qpdf/libqpdf/QPDFObjectHandle.cc

#include <qpdf/QPDFObjectHandle.hh>

#include <qpdf/BufferInputSource.hh>
#include <qpdf/Pl_Buffer.hh>
#include <qpdf/Pl_QPDFTokenizer.hh>
#include <qpdf/QPDF.hh>
#include <qpdf/QPDFExc.hh>
#include <qpdf/QPDFMatrix.hh>
#include <qpdf/QPDFPageObjectHelper.hh>
#include <qpdf/QPDF_Array.hh>
#include <qpdf/QPDF_Bool.hh>
#include <qpdf/QPDF_Dictionary.hh>
#include <qpdf/QPDF_InlineImage.hh>
#include <qpdf/QPDF_Integer.hh>
#include <qpdf/QPDF_Name.hh>
#include <qpdf/QPDF_Null.hh>
#include <qpdf/QPDF_Operator.hh>
#include <qpdf/QPDF_Real.hh>
#include <qpdf/QPDF_Reserved.hh>
#include <qpdf/QPDF_Stream.hh>
#include <qpdf/QPDF_String.hh>
#include <qpdf/SparseOHArray.hh>

#include <qpdf/QIntC.hh>
#include <qpdf/QTC.hh>
#include <qpdf/QUtil.hh>

#include <algorithm>
#include <cstring>
#include <ctype.h>
#include <limits.h>
#include <stdexcept>
#include <stdlib.h>

namespace
{
    class TerminateParsing
    {
    };
} // namespace

QPDFObjectHandle::StreamDataProvider::StreamDataProvider(bool supports_retry) :
    supports_retry(supports_retry)
{
}

QPDFObjectHandle::StreamDataProvider::~StreamDataProvider()
{
    // Must be explicit and not inline -- see QPDF_DLL_CLASS in
    // README-maintainer
}

void
QPDFObjectHandle::StreamDataProvider::provideStreamData(
    int objid, int generation, Pipeline* pipeline)
{
    throw std::logic_error(
        "you must override provideStreamData -- see QPDFObjectHandle.hh");
}

bool
QPDFObjectHandle::StreamDataProvider::provideStreamData(
    int objid,
    int generation,
    Pipeline* pipeline,
    bool suppress_warnings,
    bool will_retry)
{
    throw std::logic_error(
        "you must override provideStreamData -- see QPDFObjectHandle.hh");
    return false;
}

bool
QPDFObjectHandle::StreamDataProvider::supportsRetry()
{
    return this->supports_retry;
}

namespace
{
    class CoalesceProvider: public QPDFObjectHandle::StreamDataProvider
    {
      public:
        CoalesceProvider(
            QPDFObjectHandle containing_page, QPDFObjectHandle old_contents) :
            containing_page(containing_page),
            old_contents(old_contents)
        {
        }
        virtual ~CoalesceProvider() = default;
        virtual void
        provideStreamData(int objid, int generation, Pipeline* pipeline);

      private:
        QPDFObjectHandle containing_page;
        QPDFObjectHandle old_contents;
    };
} // namespace

void
CoalesceProvider::provideStreamData(int, int, Pipeline* p)
{
    QTC::TC("qpdf", "QPDFObjectHandle coalesce provide stream data");
    std::string description = "page object " +
        QUtil::int_to_string(containing_page.getObjectID()) + " " +
        QUtil::int_to_string(containing_page.getGeneration());
    std::string all_description;
    old_contents.pipeContentStreams(p, description, all_description);
}

void
QPDFObjectHandle::TokenFilter::handleEOF()
{
}

void
QPDFObjectHandle::TokenFilter::setPipeline(Pipeline* p)
{
    this->pipeline = p;
}

void
QPDFObjectHandle::TokenFilter::write(char const* data, size_t len)
{
    if (!this->pipeline) {
        return;
    }
    if (len) {
        this->pipeline->write(data, len);
    }
}

void
QPDFObjectHandle::TokenFilter::write(std::string const& str)
{
    write(str.c_str(), str.length());
}

void
QPDFObjectHandle::TokenFilter::writeToken(QPDFTokenizer::Token const& token)
{
    std::string value = token.getRawValue();
    write(value.c_str(), value.length());
}

void
QPDFObjectHandle::ParserCallbacks::handleObject(QPDFObjectHandle)
{
    throw std::logic_error("You must override one of the"
                           " handleObject methods in ParserCallbacks");
}

void
QPDFObjectHandle::ParserCallbacks::handleObject(
    QPDFObjectHandle oh, size_t, size_t)
{
    // This version of handleObject was added in qpdf 9. If the
    // developer did not override it, fall back to the older
    // interface.
    handleObject(oh);
}

void
QPDFObjectHandle::ParserCallbacks::contentSize(size_t)
{
    // Ignore by default; overriding this is optional.
}

void
QPDFObjectHandle::ParserCallbacks::terminateParsing()
{
    throw TerminateParsing();
}

namespace
{
    class LastChar: public Pipeline
    {
      public:
        LastChar(Pipeline* next);
        virtual ~LastChar() = default;
        virtual void write(unsigned char const* data, size_t len);
        virtual void finish();
        unsigned char getLastChar();

      private:
        unsigned char last_char;
    };
} // namespace

LastChar::LastChar(Pipeline* next) :
    Pipeline("lastchar", next),
    last_char(0)
{
}

void
LastChar::write(unsigned char const* data, size_t len)
{
    if (len > 0) {
        this->last_char = data[len - 1];
    }
    getNext()->write(data, len);
}

void
LastChar::finish()
{
    getNext()->finish();
}

unsigned char
LastChar::getLastChar()
{
    return this->last_char;
}

QPDFObjectHandle::QPDFObjectHandle() :
    initialized(false),
    qpdf(0),
    objid(0),
    generation(0),
    reserved(false)
{
}

QPDFObjectHandle::QPDFObjectHandle(QPDF* qpdf, int objid, int generation) :
    initialized(true),
    qpdf(qpdf),
    objid(objid),
    generation(generation),
    reserved(false)
{
}

QPDFObjectHandle::QPDFObjectHandle(QPDFObject* data) :
    initialized(true),
    qpdf(0),
    objid(0),
    generation(0),
    obj(data),
    reserved(false)
{
}

void
QPDFObjectHandle::releaseResolved()
{
    // Recursively break any resolved references to indirect objects.
    // Do not cross over indirect object boundaries to avoid an
    // infinite loop.  This method may only be called during final
    // destruction.  See comments in QPDF::~QPDF().
    if (isIndirect()) {
        if (this->obj.get()) {
            this->obj = 0;
        }
    } else {
        QPDFObject::ObjAccessor::releaseResolved(this->obj.get());
    }
}

void
QPDFObjectHandle::setObjectDescriptionFromInput(
    QPDFObjectHandle object,
    QPDF* context,
    std::string const& description,
    std::shared_ptr<InputSource> input,
    qpdf_offset_t offset)
{
    object.setObjectDescription(
        context,
        (input->getName() + ", " + description + " at offset " +
         QUtil::int_to_string(offset)));
}

bool
QPDFObjectHandle::isInitialized() const
{
    return this->initialized;
}

QPDFObject::object_type_e
QPDFObjectHandle::getTypeCode()
{
    if (this->initialized) {
        dereference();
        return this->obj->getTypeCode();
    } else {
        return QPDFObject::ot_uninitialized;
    }
}

char const*
QPDFObjectHandle::getTypeName()
{
    if (this->initialized) {
        dereference();
        return this->obj->getTypeName();
    } else {
        return "uninitialized";
    }
}

namespace
{
    template <class T>
    class QPDFObjectTypeAccessor
    {
      public:
        static bool
        check(QPDFObject* o)
        {
            return (o && dynamic_cast<T*>(o));
        }
        static bool
        check(QPDFObject const* o)
        {
            return (o && dynamic_cast<T const*>(o));
        }
    };
} // namespace

bool
QPDFObjectHandle::isBool()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_Bool>::check(obj.get());
}

bool
QPDFObjectHandle::isDirectNull() const
{
    // Don't call dereference() -- this is a const method, and we know
    // objid == 0, so there's nothing to resolve.
    return (
        this->initialized && (this->objid == 0) &&
        QPDFObjectTypeAccessor<QPDF_Null>::check(obj.get()));
}

bool
QPDFObjectHandle::isNull()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_Null>::check(obj.get());
}

bool
QPDFObjectHandle::isInteger()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_Integer>::check(obj.get());
}

bool
QPDFObjectHandle::isReal()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_Real>::check(obj.get());
}

bool
QPDFObjectHandle::isNumber()
{
    return (isInteger() || isReal());
}

double
QPDFObjectHandle::getNumericValue()
{
    double result = 0.0;
    if (isInteger()) {
        result = static_cast<double>(getIntValue());
    } else if (isReal()) {
        result = atof(getRealValue().c_str());
    } else {
        typeWarning("number", "returning 0");
        QTC::TC("qpdf", "QPDFObjectHandle numeric non-numeric");
    }
    return result;
}

bool
QPDFObjectHandle::getValueAsNumber(double& value)
{
    if (!isNumber()) {
        return false;
    }
    value = getNumericValue();
    return true;
}

bool
QPDFObjectHandle::isName()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_Name>::check(obj.get());
}

bool
QPDFObjectHandle::isString()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_String>::check(obj.get());
}

bool
QPDFObjectHandle::isOperator()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_Operator>::check(obj.get());
}

bool
QPDFObjectHandle::isInlineImage()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_InlineImage>::check(obj.get());
}

bool
QPDFObjectHandle::isArray()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_Array>::check(obj.get());
}

bool
QPDFObjectHandle::isDictionary()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_Dictionary>::check(obj.get());
}

bool
QPDFObjectHandle::isStream()
{
    if (!this->initialized) {
        return false;
    }
    dereference();
    return QPDFObjectTypeAccessor<QPDF_Stream>::check(obj.get());
}

bool
QPDFObjectHandle::isReserved()
{
    if (!this->initialized) {
        return false;
    }
    // dereference will clear reserved if this has been replaced
    dereference();
    return this->reserved;
}

bool
QPDFObjectHandle::isIndirect()
{
    if (!this->initialized) {
        return false;
    }
    return (this->objid != 0);
}

bool
QPDFObjectHandle::isScalar()
{
    return (
        !(isArray() || isDictionary() || isStream() || isOperator() ||
          isInlineImage()));
}

bool
QPDFObjectHandle::isNameAndEquals(std::string const& name)
{
    return isName() && (getName() == name);
}

bool
QPDFObjectHandle::isDictionaryOfType(
    std::string const& type, std::string const& subtype)
{
    return isDictionary() &&
        (type.empty() || getKey("/Type").isNameAndEquals(type)) &&
        (subtype.empty() || getKey("/Subtype").isNameAndEquals(subtype));
}

bool
QPDFObjectHandle::isStreamOfType(
    std::string const& type, std::string const& subtype)
{
    return isStream() && getDict().isDictionaryOfType(type, subtype);
}

// Bool accessors

bool
QPDFObjectHandle::getBoolValue()
{
    if (isBool()) {
        return dynamic_cast<QPDF_Bool*>(obj.get())->getVal();
    } else {
        typeWarning("boolean", "returning false");
        QTC::TC("qpdf", "QPDFObjectHandle boolean returning false");
        return false;
    }
}

bool
QPDFObjectHandle::getValueAsBool(bool& value)
{
    if (!isBool()) {
        return false;
    }
    value = dynamic_cast<QPDF_Bool*>(obj.get())->getVal();
    return true;
}

// Integer accessors

long long
QPDFObjectHandle::getIntValue()
{
    if (isInteger()) {
        return dynamic_cast<QPDF_Integer*>(obj.get())->getVal();
    } else {
        typeWarning("integer", "returning 0");
        QTC::TC("qpdf", "QPDFObjectHandle integer returning 0");
        return 0;
    }
}

bool
QPDFObjectHandle::getValueAsInt(long long& value)
{
    if (!isInteger()) {
        return false;
    }
    value = dynamic_cast<QPDF_Integer*>(obj.get())->getVal();
    return true;
}

int
QPDFObjectHandle::getIntValueAsInt()
{
    int result = 0;
    long long v = getIntValue();
    if (v < INT_MIN) {
        QTC::TC("qpdf", "QPDFObjectHandle int returning INT_MIN");
        warnIfPossible(
            "requested value of integer is too small; returning INT_MIN",
            false);
        result = INT_MIN;
    } else if (v > INT_MAX) {
        QTC::TC("qpdf", "QPDFObjectHandle int returning INT_MAX");
        warnIfPossible(
            "requested value of integer is too big; returning INT_MAX", false);
        result = INT_MAX;
    } else {
        result = static_cast<int>(v);
    }
    return result;
}

bool
QPDFObjectHandle::getValueAsInt(int& value)
{
    if (!isInteger()) {
        return false;
    }
    value = getIntValueAsInt();
    return true;
}

unsigned long long
QPDFObjectHandle::getUIntValue()
{
    unsigned long long result = 0;
    long long v = getIntValue();
    if (v < 0) {
        QTC::TC("qpdf", "QPDFObjectHandle uint returning 0");
        warnIfPossible(
            "unsigned value request for negative number; returning 0", false);
    } else {
        result = static_cast<unsigned long long>(v);
    }
    return result;
}

bool
QPDFObjectHandle::getValueAsUInt(unsigned long long& value)
{
    if (!isInteger()) {
        return false;
    }
    value = getUIntValue();
    return true;
}

unsigned int
QPDFObjectHandle::getUIntValueAsUInt()
{
    unsigned int result = 0;
    long long v = getIntValue();
    if (v < 0) {
        QTC::TC("qpdf", "QPDFObjectHandle uint uint returning 0");
        warnIfPossible(
            "unsigned integer value request for negative number; returning 0",
            false);
        result = 0;
    } else if (v > UINT_MAX) {
        QTC::TC("qpdf", "QPDFObjectHandle uint returning UINT_MAX");
        warnIfPossible(
            "requested value of unsigned integer is too big;"
            " returning UINT_MAX",
            false);
        result = UINT_MAX;
    } else {
        result = static_cast<unsigned int>(v);
    }
    return result;
}

bool
QPDFObjectHandle::getValueAsUInt(unsigned int& value)
{
    if (!isInteger()) {
        return false;
    }
    value = getUIntValueAsUInt();
    return true;
}

// Real accessors

std::string
QPDFObjectHandle::getRealValue()
{
    if (isReal()) {
        return dynamic_cast<QPDF_Real*>(obj.get())->getVal();
    } else {
        typeWarning("real", "returning 0.0");
        QTC::TC("qpdf", "QPDFObjectHandle real returning 0.0");
        return "0.0";
    }
}

bool
QPDFObjectHandle::getValueAsReal(std::string& value)
{
    if (!isReal()) {
        return false;
    }
    value = dynamic_cast<QPDF_Real*>(obj.get())->getVal();
    return true;
}

// Name accessors

std::string
QPDFObjectHandle::getName()
{
    if (isName()) {
        return dynamic_cast<QPDF_Name*>(obj.get())->getName();
    } else {
        typeWarning("name", "returning dummy name");
        QTC::TC("qpdf", "QPDFObjectHandle name returning dummy name");
        return "/QPDFFakeName";
    }
}

bool
QPDFObjectHandle::getValueAsName(std::string& value)
{
    if (!isName()) {
        return false;
    }
    value = dynamic_cast<QPDF_Name*>(obj.get())->getName();
    return true;
}

// String accessors

std::string
QPDFObjectHandle::getStringValue()
{
    if (isString()) {
        return dynamic_cast<QPDF_String*>(obj.get())->getVal();
    } else {
        typeWarning("string", "returning empty string");
        QTC::TC("qpdf", "QPDFObjectHandle string returning empty string");
        return "";
    }
}

bool
QPDFObjectHandle::getValueAsString(std::string& value)
{
    if (!isString()) {
        return false;
    }
    value = dynamic_cast<QPDF_String*>(obj.get())->getVal();
    return true;
}

std::string
QPDFObjectHandle::getUTF8Value()
{
    if (isString()) {
        return dynamic_cast<QPDF_String*>(obj.get())->getUTF8Val();
    } else {
        typeWarning("string", "returning empty string");
        QTC::TC("qpdf", "QPDFObjectHandle string returning empty utf8");
        return "";
    }
}

bool
QPDFObjectHandle::getValueAsUTF8(std::string& value)
{
    if (!isString()) {
        return false;
    }
    value = dynamic_cast<QPDF_String*>(obj.get())->getUTF8Val();
    return true;
}

// Operator and Inline Image accessors

std::string
QPDFObjectHandle::getOperatorValue()
{
    if (isOperator()) {
        return dynamic_cast<QPDF_Operator*>(obj.get())->getVal();
    } else {
        typeWarning("operator", "returning fake value");
        QTC::TC("qpdf", "QPDFObjectHandle operator returning fake value");
        return "QPDFFAKE";
    }
}

bool
QPDFObjectHandle::getValueAsOperator(std::string& value)
{
    if (!isOperator()) {
        return false;
    }
    value = dynamic_cast<QPDF_Operator*>(obj.get())->getVal();
    return true;
}

std::string
QPDFObjectHandle::getInlineImageValue()
{
    if (isInlineImage()) {
        return dynamic_cast<QPDF_InlineImage*>(obj.get())->getVal();
    } else {
        typeWarning("inlineimage", "returning empty data");
        QTC::TC("qpdf", "QPDFObjectHandle inlineimage returning empty data");
        return "";
    }
}

bool
QPDFObjectHandle::getValueAsInlineImage(std::string& value)
{
    if (!isInlineImage()) {
        return false;
    }
    value = dynamic_cast<QPDF_InlineImage*>(obj.get())->getVal();
    return true;
}

// Array accessors

QPDFObjectHandle::QPDFArrayItems
QPDFObjectHandle::aitems()
{
    return QPDFArrayItems(*this);
}

int
QPDFObjectHandle::getArrayNItems()
{
    if (isArray()) {
        return dynamic_cast<QPDF_Array*>(obj.get())->getNItems();
    } else {
        typeWarning("array", "treating as empty");
        QTC::TC("qpdf", "QPDFObjectHandle array treating as empty");
        return 0;
    }
}

QPDFObjectHandle
QPDFObjectHandle::getArrayItem(int n)
{
    QPDFObjectHandle result;
    if (isArray() && (n < getArrayNItems()) && (n >= 0)) {
        result = dynamic_cast<QPDF_Array*>(obj.get())->getItem(n);
    } else {
        result = newNull();
        if (isArray()) {
            objectWarning("returning null for out of bounds array access");
            QTC::TC("qpdf", "QPDFObjectHandle array bounds");
        } else {
            typeWarning("array", "returning null");
            QTC::TC("qpdf", "QPDFObjectHandle array null for non-array");
        }
        QPDF* context = 0;
        std::string description;
        if (this->obj->getDescription(context, description)) {
            result.setObjectDescription(
                context,
                description + " -> null returned from invalid array access");
        }
    }
    return result;
}

bool
QPDFObjectHandle::isRectangle()
{
    if (!isArray()) {
        return false;
    }
    if (getArrayNItems() != 4) {
        return false;
    }
    for (int i = 0; i < 4; ++i) {
        if (!getArrayItem(i).isNumber()) {
            return false;
        }
    }
    return true;
}

bool
QPDFObjectHandle::isMatrix()
{
    if (!isArray()) {
        return false;
    }
    if (getArrayNItems() != 6) {
        return false;
    }
    for (int i = 0; i < 6; ++i) {
        if (!getArrayItem(i).isNumber()) {
            return false;
        }
    }
    return true;
}

QPDFObjectHandle::Rectangle
QPDFObjectHandle::getArrayAsRectangle()
{
    Rectangle result;
    if (isRectangle()) {
        // Rectangle coordinates are always supposed to be llx, lly,
        // urx, ury, but files have been found in the wild where
        // llx > urx or lly > ury.
        double i0 = getArrayItem(0).getNumericValue();
        double i1 = getArrayItem(1).getNumericValue();
        double i2 = getArrayItem(2).getNumericValue();
        double i3 = getArrayItem(3).getNumericValue();
        result = Rectangle(
            std::min(i0, i2),
            std::min(i1, i3),
            std::max(i0, i2),
            std::max(i1, i3));
    }
    return result;
}

QPDFObjectHandle::Matrix
QPDFObjectHandle::getArrayAsMatrix()
{
    Matrix result;
    if (isMatrix()) {
        result = Matrix(
            getArrayItem(0).getNumericValue(),
            getArrayItem(1).getNumericValue(),
            getArrayItem(2).getNumericValue(),
            getArrayItem(3).getNumericValue(),
            getArrayItem(4).getNumericValue(),
            getArrayItem(5).getNumericValue());
    }
    return result;
}

std::vector<QPDFObjectHandle>
QPDFObjectHandle::getArrayAsVector()
{
    std::vector<QPDFObjectHandle> result;
    if (isArray()) {
        dynamic_cast<QPDF_Array*>(obj.get())->getAsVector(result);
    } else {
        typeWarning("array", "treating as empty");
        QTC::TC("qpdf", "QPDFObjectHandle array treating as empty vector");
    }
    return result;
}

// Array mutators

void
QPDFObjectHandle::setArrayItem(int n, QPDFObjectHandle const& item)
{
    if (isArray()) {
        checkOwnership(item);
        dynamic_cast<QPDF_Array*>(obj.get())->setItem(n, item);
    } else {
        typeWarning("array", "ignoring attempt to set item");
        QTC::TC("qpdf", "QPDFObjectHandle array ignoring set item");
    }
}

void
QPDFObjectHandle::setArrayFromVector(std::vector<QPDFObjectHandle> const& items)
{
    if (isArray()) {
        for (auto const& item: items) {
            checkOwnership(item);
        }
        dynamic_cast<QPDF_Array*>(obj.get())->setFromVector(items);
    } else {
        typeWarning("array", "ignoring attempt to replace items");
        QTC::TC("qpdf", "QPDFObjectHandle array ignoring replace items");
    }
}

QPDFObjectHandle&
QPDFObjectHandle::insertItem(int at, QPDFObjectHandle const& item)
{
    if (isArray()) {
        dynamic_cast<QPDF_Array*>(obj.get())->insertItem(at, item);
    } else {
        typeWarning("array", "ignoring attempt to insert item");
        QTC::TC("qpdf", "QPDFObjectHandle array ignoring insert item");
    }
    return *this;
}

QPDFObjectHandle
QPDFObjectHandle::insertItemAndGet(int at, QPDFObjectHandle const& item)
{
    insertItem(at, item);
    return item;
}

QPDFObjectHandle&
QPDFObjectHandle::appendItem(QPDFObjectHandle const& item)
{
    if (isArray()) {
        checkOwnership(item);
        dynamic_cast<QPDF_Array*>(obj.get())->appendItem(item);
    } else {
        typeWarning("array", "ignoring attempt to append item");
        QTC::TC("qpdf", "QPDFObjectHandle array ignoring append item");
    }
    return *this;
}

QPDFObjectHandle
QPDFObjectHandle::appendItemAndGet(QPDFObjectHandle const& item)
{
    appendItem(item);
    return item;
}

QPDFObjectHandle&
QPDFObjectHandle::eraseItem(int at)
{
    if (isArray() && (at < getArrayNItems()) && (at >= 0)) {
        dynamic_cast<QPDF_Array*>(obj.get())->eraseItem(at);
    } else {
        if (isArray()) {
            objectWarning("ignoring attempt to erase out of bounds array item");
            QTC::TC("qpdf", "QPDFObjectHandle erase array bounds");
        } else {
            typeWarning("array", "ignoring attempt to erase item");
            QTC::TC("qpdf", "QPDFObjectHandle array ignoring erase item");
        }
    }
    return *this;
}

QPDFObjectHandle
QPDFObjectHandle::eraseItemAndGet(int at)
{
    auto result = QPDFObjectHandle::newNull();
    if (isArray() && (at < getArrayNItems()) && (at >= 0)) {
        result = getArrayItem(at);
    }
    eraseItem(at);
    return result;
}

// Dictionary accessors

QPDFObjectHandle::QPDFDictItems
QPDFObjectHandle::ditems()
{
    return QPDFDictItems(*this);
}

bool
QPDFObjectHandle::hasKey(std::string const& key)
{
    if (isDictionary()) {
        return dynamic_cast<QPDF_Dictionary*>(obj.get())->hasKey(key);
    } else {
        typeWarning(
            "dictionary", "returning false for a key containment request");
        QTC::TC("qpdf", "QPDFObjectHandle dictionary false for hasKey");
        return false;
    }
}

QPDFObjectHandle
QPDFObjectHandle::getKey(std::string const& key)
{
    QPDFObjectHandle result;
    if (isDictionary()) {
        result = dynamic_cast<QPDF_Dictionary*>(obj.get())->getKey(key);
    } else {
        typeWarning("dictionary", "returning null for attempted key retrieval");
        QTC::TC("qpdf", "QPDFObjectHandle dictionary null for getKey");
        result = newNull();
        QPDF* qpdf = 0;
        std::string description;
        if (this->obj->getDescription(qpdf, description)) {
            result.setObjectDescription(
                qpdf,
                (description + " -> null returned from getting key " + key +
                 " from non-Dictionary"));
        }
    }
    return result;
}

QPDFObjectHandle
QPDFObjectHandle::getKeyIfDict(std::string const& key)
{
    return isNull() ? newNull() : getKey(key);
}

std::set<std::string>
QPDFObjectHandle::getKeys()
{
    std::set<std::string> result;
    if (isDictionary()) {
        result = dynamic_cast<QPDF_Dictionary*>(obj.get())->getKeys();
    } else {
        typeWarning("dictionary", "treating as empty");
        QTC::TC("qpdf", "QPDFObjectHandle dictionary empty set for getKeys");
    }
    return result;
}

std::map<std::string, QPDFObjectHandle>
QPDFObjectHandle::getDictAsMap()
{
    std::map<std::string, QPDFObjectHandle> result;
    if (isDictionary()) {
        result = dynamic_cast<QPDF_Dictionary*>(obj.get())->getAsMap();
    } else {
        typeWarning("dictionary", "treating as empty");
        QTC::TC("qpdf", "QPDFObjectHandle dictionary empty map for asMap");
    }
    return result;
}

// Array and Name accessors
bool
QPDFObjectHandle::isOrHasName(std::string const& value)
{
    if (isNameAndEquals(value)) {
        return true;
    } else if (isArray()) {
        for (auto& item: aitems()) {
            if (item.isNameAndEquals(value)) {
                return true;
            }
        }
    }
    return false;
}

void
QPDFObjectHandle::makeResourcesIndirect(QPDF& owning_qpdf)
{
    if (!isDictionary()) {
        return;
    }
    for (auto const& i1: ditems()) {
        QPDFObjectHandle sub = i1.second;
        if (!sub.isDictionary()) {
            continue;
        }
        for (auto i2: sub.ditems()) {
            std::string const& key = i2.first;
            QPDFObjectHandle val = i2.second;
            if (!val.isIndirect()) {
                sub.replaceKey(key, owning_qpdf.makeIndirectObject(val));
            }
        }
    }
}

void
QPDFObjectHandle::mergeResources(
    QPDFObjectHandle other,
    std::map<std::string, std::map<std::string, std::string>>* conflicts)
{
    if (!(isDictionary() && other.isDictionary())) {
        QTC::TC("qpdf", "QPDFObjectHandle merge top type mismatch");
        return;
    }

    auto make_og_to_name = [](QPDFObjectHandle& dict,
                              std::map<QPDFObjGen, std::string>& og_to_name) {
        for (auto i: dict.ditems()) {
            if (i.second.isIndirect()) {
                og_to_name[i.second.getObjGen()] = i.first;
            }
        }
    };

    // This algorithm is described in comments in QPDFObjectHandle.hh
    // above the declaration of mergeResources.
    for (auto o_top: other.ditems()) {
        std::string const& rtype = o_top.first;
        QPDFObjectHandle other_val = o_top.second;
        if (hasKey(rtype)) {
            QPDFObjectHandle this_val = getKey(rtype);
            if (this_val.isDictionary() && other_val.isDictionary()) {
                if (this_val.isIndirect()) {
                    // Do this even if there are no keys. Various
                    // places in the code call mergeResources with
                    // resource dictionaries that contain empty
                    // subdictionaries just to get this shallow copy
                    // functionality.
                    QTC::TC("qpdf", "QPDFObjectHandle replace with copy");
                    this_val = replaceKeyAndGet(rtype, this_val.shallowCopy());
                }
                std::map<QPDFObjGen, std::string> og_to_name;
                std::set<std::string> rnames;
                int min_suffix = 1;
                bool initialized_maps = false;
                for (auto ov_iter: other_val.ditems()) {
                    std::string const& key = ov_iter.first;
                    QPDFObjectHandle rval = ov_iter.second;
                    if (!this_val.hasKey(key)) {
                        if (!rval.isIndirect()) {
                            QTC::TC(
                                "qpdf", "QPDFObjectHandle merge shallow copy");
                            rval = rval.shallowCopy();
                        }
                        this_val.replaceKey(key, rval);
                    } else if (conflicts) {
                        if (!initialized_maps) {
                            make_og_to_name(this_val, og_to_name);
                            rnames = this_val.getResourceNames();
                            initialized_maps = true;
                        }
                        auto rval_og = rval.getObjGen();
                        if (rval.isIndirect() && og_to_name.count(rval_og)) {
                            QTC::TC("qpdf", "QPDFObjectHandle merge reuse");
                            auto new_key = og_to_name[rval_og];
                            if (new_key != key) {
                                (*conflicts)[rtype][key] = new_key;
                            }
                        } else {
                            QTC::TC("qpdf", "QPDFObjectHandle merge generate");
                            std::string new_key = getUniqueResourceName(
                                key + "_", min_suffix, &rnames);
                            (*conflicts)[rtype][key] = new_key;
                            this_val.replaceKey(new_key, rval);
                        }
                    }
                }
            } else if (this_val.isArray() && other_val.isArray()) {
                std::set<std::string> scalars;
                for (auto this_item: this_val.aitems()) {
                    if (this_item.isScalar()) {
                        scalars.insert(this_item.unparse());
                    }
                }
                for (auto other_item: other_val.aitems()) {
                    if (other_item.isScalar()) {
                        if (scalars.count(other_item.unparse()) == 0) {
                            QTC::TC("qpdf", "QPDFObjectHandle merge array");
                            this_val.appendItem(other_item);
                        } else {
                            QTC::TC("qpdf", "QPDFObjectHandle merge array dup");
                        }
                    }
                }
            }
        } else {
            QTC::TC("qpdf", "QPDFObjectHandle merge copy from other");
            replaceKey(rtype, other_val.shallowCopy());
        }
    }
}

std::set<std::string>
QPDFObjectHandle::getResourceNames()
{
    // Return second-level dictionary keys
    std::set<std::string> result;
    if (!isDictionary()) {
        return result;
    }
    std::set<std::string> keys = getKeys();
    for (auto const& key: keys) {
        QPDFObjectHandle val = getKey(key);
        if (val.isDictionary()) {
            std::set<std::string> val_keys = val.getKeys();
            for (auto const& val_key: val_keys) {
                result.insert(val_key);
            }
        }
    }
    return result;
}

std::string
QPDFObjectHandle::getUniqueResourceName(
    std::string const& prefix, int& min_suffix, std::set<std::string>* namesp)

{
    std::set<std::string> names = (namesp ? *namesp : getResourceNames());
    int max_suffix = min_suffix + QIntC::to_int(names.size());
    while (min_suffix <= max_suffix) {
        std::string candidate = prefix + QUtil::int_to_string(min_suffix);
        if (names.count(candidate) == 0) {
            return candidate;
        }
        // Increment after return; min_suffix should be the value
        // used, not the next value.
        ++min_suffix;
    }
    // This could only happen if there is a coding error.
    // The number of candidates we test is more than the
    // number of keys we're checking against.
    throw std::logic_error("unable to find unconflicting name in"
                           " QPDFObjectHandle::getUniqueResourceName");
}

// Indirect object accessors
QPDF*
QPDFObjectHandle::getOwningQPDF()
{
    // Will be null for direct objects
    return this->qpdf;
}

// Dictionary mutators

QPDFObjectHandle&
QPDFObjectHandle::replaceKey(
    std::string const& key, QPDFObjectHandle const& value)
{
    if (isDictionary()) {
        checkOwnership(value);
        dynamic_cast<QPDF_Dictionary*>(obj.get())->replaceKey(key, value);
    } else {
        typeWarning("dictionary", "ignoring key replacement request");
        QTC::TC("qpdf", "QPDFObjectHandle dictionary ignoring replaceKey");
    }
    return *this;
}

QPDFObjectHandle
QPDFObjectHandle::replaceKeyAndGet(
    std::string const& key, QPDFObjectHandle const& value)
{
    replaceKey(key, value);
    return value;
}

QPDFObjectHandle&
QPDFObjectHandle::removeKey(std::string const& key)
{
    if (isDictionary()) {
        dynamic_cast<QPDF_Dictionary*>(obj.get())->removeKey(key);
    } else {
        typeWarning("dictionary", "ignoring key removal request");
        QTC::TC("qpdf", "QPDFObjectHandle dictionary ignoring removeKey");
    }
    return *this;
}

QPDFObjectHandle
QPDFObjectHandle::removeKeyAndGet(std::string const& key)
{
    auto result = QPDFObjectHandle::newNull();
    if (isDictionary()) {
        result = getKey(key);
    }
    removeKey(key);
    return result;
}

void
QPDFObjectHandle::replaceOrRemoveKey(
    std::string const& key, QPDFObjectHandle const& value)
{
    replaceKey(key, value);
}

// Stream accessors
QPDFObjectHandle
QPDFObjectHandle::getDict()
{
    assertStream();
    return dynamic_cast<QPDF_Stream*>(obj.get())->getDict();
}

void
QPDFObjectHandle::setFilterOnWrite(bool val)
{
    assertStream();
    dynamic_cast<QPDF_Stream*>(obj.get())->setFilterOnWrite(val);
}

bool
QPDFObjectHandle::getFilterOnWrite()
{
    assertStream();
    return dynamic_cast<QPDF_Stream*>(obj.get())->getFilterOnWrite();
}

bool
QPDFObjectHandle::isDataModified()
{
    assertStream();
    return dynamic_cast<QPDF_Stream*>(obj.get())->isDataModified();
}

void
QPDFObjectHandle::replaceDict(QPDFObjectHandle const& new_dict)
{
    assertStream();
    dynamic_cast<QPDF_Stream*>(obj.get())->replaceDict(new_dict);
}

std::shared_ptr<Buffer>
QPDFObjectHandle::getStreamData(qpdf_stream_decode_level_e level)
{
    assertStream();
    return dynamic_cast<QPDF_Stream*>(obj.get())->getStreamData(level);
}

std::shared_ptr<Buffer>
QPDFObjectHandle::getRawStreamData()
{
    assertStream();
    return dynamic_cast<QPDF_Stream*>(obj.get())->getRawStreamData();
}

bool
QPDFObjectHandle::pipeStreamData(
    Pipeline* p,
    bool* filtering_attempted,
    int encode_flags,
    qpdf_stream_decode_level_e decode_level,
    bool suppress_warnings,
    bool will_retry)
{
    assertStream();
    return dynamic_cast<QPDF_Stream*>(obj.get())->pipeStreamData(
        p,
        filtering_attempted,
        encode_flags,
        decode_level,
        suppress_warnings,
        will_retry);
}

bool
QPDFObjectHandle::pipeStreamData(
    Pipeline* p,
    int encode_flags,
    qpdf_stream_decode_level_e decode_level,
    bool suppress_warnings,
    bool will_retry)
{
    assertStream();
    bool filtering_attempted;
    dynamic_cast<QPDF_Stream*>(obj.get())->pipeStreamData(
        p,
        &filtering_attempted,
        encode_flags,
        decode_level,
        suppress_warnings,
        will_retry);
    return filtering_attempted;
}

bool
QPDFObjectHandle::pipeStreamData(
    Pipeline* p, bool filter, bool normalize, bool compress)
{
    int encode_flags = 0;
    qpdf_stream_decode_level_e decode_level = qpdf_dl_none;
    if (filter) {
        decode_level = qpdf_dl_generalized;
        if (normalize) {
            encode_flags |= qpdf_ef_normalize;
        }
        if (compress) {
            encode_flags |= qpdf_ef_compress;
        }
    }
    return pipeStreamData(p, encode_flags, decode_level, false);
}

void
QPDFObjectHandle::replaceStreamData(
    std::shared_ptr<Buffer> data,
    QPDFObjectHandle const& filter,
    QPDFObjectHandle const& decode_parms)
{
    assertStream();
    dynamic_cast<QPDF_Stream*>(obj.get())->replaceStreamData(
        data, filter, decode_parms);
}

void
QPDFObjectHandle::replaceStreamData(
    std::string const& data,
    QPDFObjectHandle const& filter,
    QPDFObjectHandle const& decode_parms)
{
    assertStream();
    auto b = std::make_shared<Buffer>(data.length());
    unsigned char* bp = b->getBuffer();
    memcpy(bp, data.c_str(), data.length());
    dynamic_cast<QPDF_Stream*>(obj.get())->replaceStreamData(
        b, filter, decode_parms);
}

void
QPDFObjectHandle::replaceStreamData(
    std::shared_ptr<StreamDataProvider> provider,
    QPDFObjectHandle const& filter,
    QPDFObjectHandle const& decode_parms)
{
    assertStream();
    dynamic_cast<QPDF_Stream*>(obj.get())->replaceStreamData(
        provider, filter, decode_parms);
}

namespace
{
    class FunctionProvider: public QPDFObjectHandle::StreamDataProvider
    {
      public:
        FunctionProvider(std::function<void(Pipeline*)> provider) :
            StreamDataProvider(false),
            p1(provider),
            p2(nullptr)
        {
        }
        FunctionProvider(std::function<bool(Pipeline*, bool, bool)> provider) :
            StreamDataProvider(true),
            p1(nullptr),
            p2(provider)
        {
        }

        virtual void
        provideStreamData(int, int, Pipeline* pipeline) override
        {
            p1(pipeline);
        }

        virtual bool
        provideStreamData(
            int,
            int,
            Pipeline* pipeline,
            bool suppress_warnings,
            bool will_retry) override
        {
            return p2(pipeline, suppress_warnings, will_retry);
        }

      private:
        std::function<void(Pipeline*)> p1;
        std::function<bool(Pipeline*, bool, bool)> p2;
    };
} // namespace

void
QPDFObjectHandle::replaceStreamData(
    std::function<void(Pipeline*)> provider,
    QPDFObjectHandle const& filter,
    QPDFObjectHandle const& decode_parms)
{
    assertStream();
    auto sdp =
        std::shared_ptr<StreamDataProvider>(new FunctionProvider(provider));
    dynamic_cast<QPDF_Stream*>(obj.get())->replaceStreamData(
        sdp, filter, decode_parms);
}

void
QPDFObjectHandle::replaceStreamData(
    std::function<bool(Pipeline*, bool, bool)> provider,
    QPDFObjectHandle const& filter,
    QPDFObjectHandle const& decode_parms)
{
    assertStream();
    auto sdp =
        std::shared_ptr<StreamDataProvider>(new FunctionProvider(provider));
    dynamic_cast<QPDF_Stream*>(obj.get())->replaceStreamData(
        sdp, filter, decode_parms);
}

QPDFObjGen
QPDFObjectHandle::getObjGen() const
{
    return QPDFObjGen(this->objid, this->generation);
}

int
QPDFObjectHandle::getObjectID() const
{
    return this->objid;
}

int
QPDFObjectHandle::getGeneration() const
{
    return this->generation;
}

std::map<std::string, QPDFObjectHandle>
QPDFObjectHandle::getPageImages()
{
    return QPDFPageObjectHelper(*this).getImages();
}

std::vector<QPDFObjectHandle>
QPDFObjectHandle::arrayOrStreamToStreamArray(
    std::string const& description, std::string& all_description)
{
    all_description = description;
    std::vector<QPDFObjectHandle> result;
    if (isArray()) {
        int n_items = getArrayNItems();
        for (int i = 0; i < n_items; ++i) {
            QPDFObjectHandle item = getArrayItem(i);
            if (item.isStream()) {
                result.push_back(item);
            } else {
                QTC::TC("qpdf", "QPDFObjectHandle non-stream in stream array");
                warn(
                    item.getOwningQPDF(),
                    QPDFExc(
                        qpdf_e_damaged_pdf,
                        "",
                        description + ": item index " +
                            QUtil::int_to_string(i) + " (from 0)",
                        0,
                        "ignoring non-stream in an array of streams"));
            }
        }
    } else if (isStream()) {
        result.push_back(*this);
    } else if (!isNull()) {
        warn(
            getOwningQPDF(),
            QPDFExc(
                qpdf_e_damaged_pdf,
                "",
                description,
                0,
                " object is supposed to be a stream or an"
                " array of streams but is neither"));
    }

    bool first = true;
    for (auto const& item: result) {
        std::string og = QUtil::int_to_string(item.getObjectID()) + " " +
            QUtil::int_to_string(item.getGeneration());
        if (first) {
            first = false;
        } else {
            all_description += ",";
        }
        all_description += " stream " + og;
    }

    return result;
}

std::vector<QPDFObjectHandle>
QPDFObjectHandle::getPageContents()
{
    std::string description = "page object " +
        QUtil::int_to_string(this->objid) + " " +
        QUtil::int_to_string(this->generation);
    std::string all_description;
    return this->getKey("/Contents")
        .arrayOrStreamToStreamArray(description, all_description);
}

void
QPDFObjectHandle::addPageContents(QPDFObjectHandle new_contents, bool first)
{
    new_contents.assertStream();

    std::vector<QPDFObjectHandle> orig_contents = getPageContents();

    std::vector<QPDFObjectHandle> content_streams;
    if (first) {
        QTC::TC("qpdf", "QPDFObjectHandle prepend page contents");
        content_streams.push_back(new_contents);
    }
    for (auto const& iter: orig_contents) {
        QTC::TC("qpdf", "QPDFObjectHandle append page contents");
        content_streams.push_back(iter);
    }
    if (!first) {
        content_streams.push_back(new_contents);
    }

    QPDFObjectHandle contents = QPDFObjectHandle::newArray(content_streams);
    this->replaceKey("/Contents", contents);
}

void
QPDFObjectHandle::rotatePage(int angle, bool relative)
{
    if ((angle % 90) != 0) {
        throw std::runtime_error("QPDF::rotatePage called with an"
                                 " angle that is not a multiple of 90");
    }
    int new_angle = angle;
    if (relative) {
        int old_angle = 0;
        bool found_rotate = false;
        QPDFObjectHandle cur_obj = *this;
        bool searched_parent = false;
        std::set<QPDFObjGen> visited;
        while (!found_rotate) {
            if (visited.count(cur_obj.getObjGen())) {
                // Don't get stuck in an infinite loop
                break;
            }
            if (!visited.empty()) {
                searched_parent = true;
            }
            visited.insert(cur_obj.getObjGen());
            if (cur_obj.getKey("/Rotate").isInteger()) {
                found_rotate = true;
                old_angle = cur_obj.getKey("/Rotate").getIntValueAsInt();
            } else if (cur_obj.getKey("/Parent").isDictionary()) {
                cur_obj = cur_obj.getKey("/Parent");
            } else {
                break;
            }
        }
        QTC::TC(
            "qpdf",
            "QPDFObjectHandle found old angle",
            searched_parent ? 0 : 1);
        if ((old_angle % 90) != 0) {
            old_angle = 0;
        }
        new_angle += old_angle;
    }
    new_angle = (new_angle + 360) % 360;
    // Make this explicit even with new_angle == 0 since /Rotate can
    // be inherited.
    replaceKey("/Rotate", QPDFObjectHandle::newInteger(new_angle));
}

void
QPDFObjectHandle::coalesceContentStreams()
{
    QPDFObjectHandle contents = this->getKey("/Contents");
    if (contents.isStream()) {
        QTC::TC("qpdf", "QPDFObjectHandle coalesce called on stream");
        return;
    } else if (!contents.isArray()) {
        // /Contents is optional for pages, and some very damaged
        // files may have pages that are invalid in other ways.
        return;
    }
    QPDF* qpdf = getOwningQPDF();
    if (qpdf == 0) {
        // Should not be possible for a page object to not have an
        // owning PDF unless it was manually constructed in some
        // incorrect way. However, it can happen in a PDF file whose
        // page structure is direct, which is against spec but still
        // possible to hand construct, as in fuzz issue 27393.
        throw std::runtime_error("coalesceContentStreams called on object"
                                 " with no associated PDF file");
    }
    QPDFObjectHandle new_contents = newStream(qpdf);
    this->replaceKey("/Contents", new_contents);

    auto provider = std::shared_ptr<StreamDataProvider>(
        new CoalesceProvider(*this, contents));
    new_contents.replaceStreamData(provider, newNull(), newNull());
}

std::string
QPDFObjectHandle::unparse()
{
    std::string result;
    if (this->isIndirect()) {
        result = QUtil::int_to_string(this->objid) + " " +
            QUtil::int_to_string(this->generation) + " R";
    } else {
        result = unparseResolved();
    }
    return result;
}

std::string
QPDFObjectHandle::unparseResolved()
{
    dereference();
    if (this->reserved) {
        throw std::logic_error(
            "QPDFObjectHandle: attempting to unparse a reserved object");
    }
    return this->obj->unparse();
}

std::string
QPDFObjectHandle::unparseBinary()
{
    if (this->isString()) {
        return dynamic_cast<QPDF_String*>(this->obj.get())->unparse(true);
    } else {
        return unparse();
    }
}

// Deprecated versionless getJSON to be removed in qpdf 12
JSON
QPDFObjectHandle::getJSON(bool dereference_indirect)
{
    return getJSON(1, dereference_indirect);
}

JSON
QPDFObjectHandle::getJSON(int json_version, bool dereference_indirect)
{
    if ((!dereference_indirect) && this->isIndirect()) {
        return JSON::makeString(unparse());
    } else {
        dereference();
        if (this->reserved) {
            throw std::logic_error(
                "QPDFObjectHandle: attempting to unparse a reserved object");
        }
        return this->obj->getJSON(json_version);
    }
}

JSON
QPDFObjectHandle::getStreamJSON(
    int json_version,
    qpdf_stream_data_json_e json_data,
    qpdf_stream_decode_level_e decode_level,
    Pipeline* p,
    std::string const& data_filename)
{
    assertStream();
    return dynamic_cast<QPDF_Stream*>(obj.get())->getStreamJSON(
        json_version, json_data, decode_level, p, data_filename);
}

QPDFObjectHandle
QPDFObjectHandle::wrapInArray()
{
    if (isArray()) {
        return *this;
    }
    QPDFObjectHandle result = QPDFObjectHandle::newArray();
    result.appendItem(*this);
    return result;
}

QPDFObjectHandle
QPDFObjectHandle::parse(
    std::string const& object_str, std::string const& object_description)
{
    return parse(nullptr, object_str, object_description);
}

QPDFObjectHandle
QPDFObjectHandle::parse(
    QPDF* context,
    std::string const& object_str,
    std::string const& object_description)
{
    auto input = std::shared_ptr<InputSource>(
        new BufferInputSource("parsed object", object_str));
    QPDFTokenizer tokenizer;
    bool empty = false;
    QPDFObjectHandle result =
        parse(input, object_description, tokenizer, empty, 0, context);
    size_t offset = QIntC::to_size(input->tell());
    while (offset < object_str.length()) {
        if (!isspace(object_str.at(offset))) {
            QTC::TC("qpdf", "QPDFObjectHandle trailing data in parse");
            throw QPDFExc(
                qpdf_e_damaged_pdf,
                input->getName(),
                object_description,
                input->getLastOffset(),
                "trailing data found parsing object from string");
        }
        ++offset;
    }
    return result;
}

void
QPDFObjectHandle::pipePageContents(Pipeline* p)
{
    std::string description = "page object " +
        QUtil::int_to_string(this->objid) + " " +
        QUtil::int_to_string(this->generation);
    std::string all_description;
    this->getKey("/Contents")
        .pipeContentStreams(p, description, all_description);
}

void
QPDFObjectHandle::pipeContentStreams(
    Pipeline* p, std::string const& description, std::string& all_description)
{
    std::vector<QPDFObjectHandle> streams =
        arrayOrStreamToStreamArray(description, all_description);
    bool need_newline = false;
    Pl_Buffer buf("concatenated content stream buffer");
    for (auto stream: streams) {
        if (need_newline) {
            buf.writeCStr("\n");
        }
        LastChar lc(&buf);
        std::string og = QUtil::int_to_string(stream.getObjectID()) + " " +
            QUtil::int_to_string(stream.getGeneration());
        std::string w_description = "content stream object " + og;
        if (!stream.pipeStreamData(&lc, 0, qpdf_dl_specialized)) {
            QTC::TC("qpdf", "QPDFObjectHandle errors in parsecontent");
            throw QPDFExc(
                qpdf_e_damaged_pdf,
                "content stream",
                w_description,
                0,
                "errors while decoding content stream");
        }
        lc.finish();
        need_newline = (lc.getLastChar() != static_cast<unsigned char>('\n'));
        QTC::TC("qpdf", "QPDFObjectHandle need_newline", need_newline ? 0 : 1);
    }
    std::unique_ptr<Buffer> b(buf.getBuffer());
    p->write(b->getBuffer(), b->getSize());
    p->finish();
}

void
QPDFObjectHandle::parsePageContents(ParserCallbacks* callbacks)
{
    std::string description = "page object " +
        QUtil::int_to_string(this->objid) + " " +
        QUtil::int_to_string(this->generation);
    this->getKey("/Contents")
        .parseContentStream_internal(description, callbacks);
}

void
QPDFObjectHandle::parseAsContents(ParserCallbacks* callbacks)
{
    std::string description = "object " + QUtil::int_to_string(this->objid) +
        " " + QUtil::int_to_string(this->generation);
    this->parseContentStream_internal(description, callbacks);
}

void
QPDFObjectHandle::filterPageContents(TokenFilter* filter, Pipeline* next)
{
    std::string description = "token filter for page object " +
        QUtil::int_to_string(this->objid) + " " +
        QUtil::int_to_string(this->generation);
    Pl_QPDFTokenizer token_pipeline(description.c_str(), filter, next);
    this->pipePageContents(&token_pipeline);
}

void
QPDFObjectHandle::filterAsContents(TokenFilter* filter, Pipeline* next)
{
    std::string description = "token filter for object " +
        QUtil::int_to_string(this->objid) + " " +
        QUtil::int_to_string(this->generation);
    Pl_QPDFTokenizer token_pipeline(description.c_str(), filter, next);
    this->pipeStreamData(&token_pipeline, 0, qpdf_dl_specialized);
}

void
QPDFObjectHandle::parseContentStream(
    QPDFObjectHandle stream_or_array, ParserCallbacks* callbacks)
{
    stream_or_array.parseContentStream_internal(
        "content stream objects", callbacks);
}

void
QPDFObjectHandle::parseContentStream_internal(
    std::string const& description, ParserCallbacks* callbacks)
{
    Pl_Buffer buf("concatenated stream data buffer");
    std::string all_description;
    pipeContentStreams(&buf, description, all_description);
    auto stream_data = buf.getBufferSharedPointer();
    callbacks->contentSize(stream_data->getSize());
    try {
        parseContentStream_data(
            stream_data, all_description, callbacks, getOwningQPDF());
    } catch (TerminateParsing&) {
        return;
    }
    callbacks->handleEOF();
}

void
QPDFObjectHandle::parseContentStream_data(
    std::shared_ptr<Buffer> stream_data,
    std::string const& description,
    ParserCallbacks* callbacks,
    QPDF* context)
{
    size_t stream_length = stream_data->getSize();
    auto input = std::shared_ptr<InputSource>(
        new BufferInputSource(description, stream_data.get()));
    QPDFTokenizer tokenizer;
    tokenizer.allowEOF();
    bool empty = false;
    while (QIntC::to_size(input->tell()) < stream_length) {
        // Read a token and seek to the beginning. The offset we get
        // from this process is the beginning of the next
        // non-ignorable (space, comment) token. This way, the offset
        // and don't including ignorable content.
        tokenizer.readToken(input, "content", true);
        qpdf_offset_t offset = input->getLastOffset();
        input->seek(offset, SEEK_SET);
        QPDFObjectHandle obj =
            parseInternal(input, "content", tokenizer, empty, 0, context, true);
        if (!obj.isInitialized()) {
            // EOF
            break;
        }
        size_t length = QIntC::to_size(input->tell() - offset);

        callbacks->handleObject(obj, QIntC::to_size(offset), length);
        if (obj.isOperator() && (obj.getOperatorValue() == "ID")) {
            // Discard next character; it is the space after ID that
            // terminated the token.  Read until end of inline image.
            char ch;
            input->read(&ch, 1);
            tokenizer.expectInlineImage(input);
            QPDFTokenizer::Token t =
                tokenizer.readToken(input, description, true);
            offset = input->getLastOffset();
            length = QIntC::to_size(input->tell() - offset);
            if (t.getType() == QPDFTokenizer::tt_bad) {
                QTC::TC("qpdf", "QPDFObjectHandle EOF in inline image");
                warn(
                    context,
                    QPDFExc(
                        qpdf_e_damaged_pdf,
                        input->getName(),
                        "stream data",
                        input->tell(),
                        "EOF found while reading inline image"));
            } else {
                std::string inline_image = t.getValue();
                QTC::TC("qpdf", "QPDFObjectHandle inline image token");
                callbacks->handleObject(
                    QPDFObjectHandle::newInlineImage(inline_image),
                    QIntC::to_size(offset),
                    length);
            }
        }
    }
}

void
QPDFObjectHandle::addContentTokenFilter(std::shared_ptr<TokenFilter> filter)
{
    coalesceContentStreams();
    this->getKey("/Contents").addTokenFilter(filter);
}

void
QPDFObjectHandle::addTokenFilter(std::shared_ptr<TokenFilter> filter)
{
    assertStream();
    return dynamic_cast<QPDF_Stream*>(obj.get())->addTokenFilter(filter);
}

QPDFObjectHandle
QPDFObjectHandle::parse(
    std::shared_ptr<InputSource> input,
    std::string const& object_description,
    QPDFTokenizer& tokenizer,
    bool& empty,
    StringDecrypter* decrypter,
    QPDF* context)
{
    return parseInternal(
        input, object_description, tokenizer, empty, decrypter, context, false);
}

QPDFObjectHandle
QPDFObjectHandle::parseInternal(
    std::shared_ptr<InputSource> input,
    std::string const& object_description,
    QPDFTokenizer& tokenizer,
    bool& empty,
    StringDecrypter* decrypter,
    QPDF* context,
    bool content_stream)
{
    // This method must take care not to resolve any objects. Don't
    // check the type of any object without first ensuring that it is
    // a direct object. Otherwise, doing so may have the side effect
    // of reading the object and changing the file pointer. If you do
    // this, it will cause a logic error to be thrown from
    // QPDF::inParse().

    QPDF::ParseGuard pg(context);

    empty = false;

    QPDFObjectHandle object;
    bool set_offset = false;

    std::vector<SparseOHArray> olist_stack;
    olist_stack.push_back(SparseOHArray());
    std::vector<parser_state_e> state_stack;
    state_stack.push_back(st_top);
    std::vector<qpdf_offset_t> offset_stack;
    qpdf_offset_t offset = input->tell();
    offset_stack.push_back(offset);
    bool done = false;
    int bad_count = 0;
    int good_count = 0;
    bool b_contents = false;
    std::vector<std::string> contents_string_stack;
    contents_string_stack.push_back("");
    std::vector<qpdf_offset_t> contents_offset_stack;
    contents_offset_stack.push_back(-1);
    while (!done) {
        bool bad = false;
        SparseOHArray& olist = olist_stack.back();
        parser_state_e state = state_stack.back();
        offset = offset_stack.back();
        std::string& contents_string = contents_string_stack.back();
        qpdf_offset_t& contents_offset = contents_offset_stack.back();

        object = QPDFObjectHandle();
        set_offset = false;

        QPDFTokenizer::Token token =
            tokenizer.readToken(input, object_description, true);
        std::string const& token_error_message = token.getErrorMessage();
        if (!token_error_message.empty()) {
            // Tokens other than tt_bad can still generate warnings.
            warn(
                context,
                QPDFExc(
                    qpdf_e_damaged_pdf,
                    input->getName(),
                    object_description,
                    input->getLastOffset(),
                    token_error_message));
        }

        switch (token.getType()) {
        case QPDFTokenizer::tt_eof:
            if (!content_stream) {
                QTC::TC("qpdf", "QPDFObjectHandle eof in parseInternal");
                warn(
                    context,
                    QPDFExc(
                        qpdf_e_damaged_pdf,
                        input->getName(),
                        object_description,
                        input->getLastOffset(),
                        "unexpected EOF"));
            }
            bad = true;
            state = st_eof;
            break;

        case QPDFTokenizer::tt_bad:
            QTC::TC("qpdf", "QPDFObjectHandle bad token in parse");
            bad = true;
            object = newNull();
            break;

        case QPDFTokenizer::tt_brace_open:
        case QPDFTokenizer::tt_brace_close:
            QTC::TC("qpdf", "QPDFObjectHandle bad brace");
            warn(
                context,
                QPDFExc(
                    qpdf_e_damaged_pdf,
                    input->getName(),
                    object_description,
                    input->getLastOffset(),
                    "treating unexpected brace token as null"));
            bad = true;
            object = newNull();
            break;

        case QPDFTokenizer::tt_array_close:
            if (state == st_array) {
                state = st_stop;
            } else {
                QTC::TC("qpdf", "QPDFObjectHandle bad array close");
                warn(
                    context,
                    QPDFExc(
                        qpdf_e_damaged_pdf,
                        input->getName(),
                        object_description,
                        input->getLastOffset(),
                        "treating unexpected array close token as null"));
                bad = true;
                object = newNull();
            }
            break;

        case QPDFTokenizer::tt_dict_close:
            if (state == st_dictionary) {
                state = st_stop;
            } else {
                QTC::TC("qpdf", "QPDFObjectHandle bad dictionary close");
                warn(
                    context,
                    QPDFExc(
                        qpdf_e_damaged_pdf,
                        input->getName(),
                        object_description,
                        input->getLastOffset(),
                        "unexpected dictionary close token"));
                bad = true;
                object = newNull();
            }
            break;

        case QPDFTokenizer::tt_array_open:
        case QPDFTokenizer::tt_dict_open:
            if (olist_stack.size() > 500) {
                QTC::TC("qpdf", "QPDFObjectHandle too deep");
                warn(
                    context,
                    QPDFExc(
                        qpdf_e_damaged_pdf,
                        input->getName(),
                        object_description,
                        input->getLastOffset(),
                        "ignoring excessively deeply nested data structure"));
                bad = true;
                object = newNull();
                state = st_top;
            } else {
                olist_stack.push_back(SparseOHArray());
                state = st_start;
                offset_stack.push_back(input->tell());
                state_stack.push_back(
                    (token.getType() == QPDFTokenizer::tt_array_open)
                        ? st_array
                        : st_dictionary);
                b_contents = false;
                contents_string_stack.push_back("");
                contents_offset_stack.push_back(-1);
            }
            break;

        case QPDFTokenizer::tt_bool:
            object = newBool((token.getValue() == "true"));
            break;

        case QPDFTokenizer::tt_null:
            object = newNull();
            break;

        case QPDFTokenizer::tt_integer:
            object = newInteger(QUtil::string_to_ll(token.getValue().c_str()));
            break;

        case QPDFTokenizer::tt_real:
            object = newReal(token.getValue());
            break;

        case QPDFTokenizer::tt_name:
            {
                std::string name = token.getValue();
                object = newName(name);

                if (name == "/Contents") {
                    b_contents = true;
                } else {
                    b_contents = false;
                }
            }
            break;

        case QPDFTokenizer::tt_word:
            {
                std::string const& value = token.getValue();
                if (content_stream) {
                    object = QPDFObjectHandle::newOperator(value);
                } else if (
                    (value == "R") && (state != st_top) &&
                    (olist.size() >= 2) &&
                    (!olist.at(olist.size() - 1).isIndirect()) &&
                    (olist.at(olist.size() - 1).isInteger()) &&
                    (!olist.at(olist.size() - 2).isIndirect()) &&
                    (olist.at(olist.size() - 2).isInteger())) {
                    if (context == 0) {
                        QTC::TC(
                            "qpdf",
                            "QPDFObjectHandle indirect without context");
                        throw std::logic_error(
                            "QPDFObjectHandle::parse called without context"
                            " on an object with indirect references");
                    }
                    // Try to resolve indirect objects
                    object = newIndirect(
                        context,
                        olist.at(olist.size() - 2).getIntValueAsInt(),
                        olist.at(olist.size() - 1).getIntValueAsInt());
                    olist.remove_last();
                    olist.remove_last();
                } else if ((value == "endobj") && (state == st_top)) {
                    // We just saw endobj without having read
                    // anything.  Treat this as a null and do not move
                    // the input source's offset.
                    object = newNull();
                    input->seek(input->getLastOffset(), SEEK_SET);
                    empty = true;
                } else {
                    QTC::TC("qpdf", "QPDFObjectHandle treat word as string");
                    warn(
                        context,
                        QPDFExc(
                            qpdf_e_damaged_pdf,
                            input->getName(),
                            object_description,
                            input->getLastOffset(),
                            "unknown token while reading object;"
                            " treating as string"));
                    bad = true;
                    object = newString(value);
                }
            }
            break;

        case QPDFTokenizer::tt_string:
            {
                std::string val = token.getValue();
                if (decrypter) {
                    if (b_contents) {
                        contents_string = val;
                        contents_offset = input->getLastOffset();
                        b_contents = false;
                    }
                    decrypter->decryptString(val);
                }
                object = QPDFObjectHandle::newString(val);
            }

            break;

        default:
            warn(
                context,
                QPDFExc(
                    qpdf_e_damaged_pdf,
                    input->getName(),
                    object_description,
                    input->getLastOffset(),
                    "treating unknown token type as null while "
                    "reading object"));
            bad = true;
            object = newNull();
            break;
        }

        if ((!object.isInitialized()) &&
            (!((state == st_start) || (state == st_stop) ||
               (state == st_eof)))) {
            throw std::logic_error("QPDFObjectHandle::parseInternal: "
                                   "unexpected uninitialized object");
            object = newNull();
        }

        if (bad) {
            ++bad_count;
            good_count = 0;
        } else {
            ++good_count;
            if (good_count > 3) {
                bad_count = 0;
            }
        }
        if (bad_count > 5) {
            // We had too many consecutive errors without enough
            // intervening successful objects. Give up.
            warn(
                context,
                QPDFExc(
                    qpdf_e_damaged_pdf,
                    input->getName(),
                    object_description,
                    input->getLastOffset(),
                    "too many errors; giving up on reading object"));
            state = st_top;
            object = newNull();
        }

        switch (state) {
        case st_eof:
            if (state_stack.size() > 1) {
                warn(
                    context,
                    QPDFExc(
                        qpdf_e_damaged_pdf,
                        input->getName(),
                        object_description,
                        input->getLastOffset(),
                        "parse error while reading object"));
            }
            done = true;
            // In content stream mode, leave object uninitialized to
            // indicate EOF
            if (!content_stream) {
                object = newNull();
            }
            break;

        case st_dictionary:
        case st_array:
            setObjectDescriptionFromInput(
                object,
                context,
                object_description,
                input,
                input->getLastOffset());
            object.setParsedOffset(input->getLastOffset());
            set_offset = true;
            olist.append(object);
            break;

        case st_top:
            done = true;
            break;

        case st_start:
            break;

        case st_stop:
            if ((state_stack.size() < 2) || (olist_stack.size() < 2)) {
                throw std::logic_error(
                    "QPDFObjectHandle::parseInternal: st_stop encountered"
                    " with insufficient elements in stack");
            }
            parser_state_e old_state = state_stack.back();
            state_stack.pop_back();
            if (old_state == st_array) {
                // There's no newArray(SparseOHArray) since
                // SparseOHArray is not part of the public API.
                object = QPDFObjectHandle(new QPDF_Array(olist));
                setObjectDescriptionFromInput(
                    object, context, object_description, input, offset);
                // The `offset` points to the next of "[". Set the
                // rewind offset to point to the beginning of "[".
                // This has been explicitly tested with whitespace
                // surrounding the array start delimiter.
                // getLastOffset points to the array end token and
                // therefore can't be used here.
                object.setParsedOffset(offset - 1);
                set_offset = true;
            } else if (old_state == st_dictionary) {
                // Convert list to map. Alternating elements are keys.
                // Attempt to recover more or less gracefully from
                // invalid dictionaries.
                std::set<std::string> names;
                size_t n_elements = olist.size();
                for (size_t i = 0; i < n_elements; ++i) {
                    QPDFObjectHandle oh = olist.at(i);
                    if ((!oh.isIndirect()) && oh.isName()) {
                        names.insert(oh.getName());
                    }
                }

                std::map<std::string, QPDFObjectHandle> dict;
                int next_fake_key = 1;
                for (unsigned int i = 0; i < olist.size(); ++i) {
                    QPDFObjectHandle key_obj = olist.at(i);
                    QPDFObjectHandle val;
                    if (key_obj.isIndirect() || (!key_obj.isName())) {
                        bool found_fake = false;
                        std::string candidate;
                        while (!found_fake) {
                            candidate = "/QPDFFake" +
                                QUtil::int_to_string(next_fake_key++);
                            found_fake = (names.count(candidate) == 0);
                            QTC::TC(
                                "qpdf",
                                "QPDFObjectHandle found fake",
                                (found_fake ? 0 : 1));
                        }
                        warn(
                            context,
                            QPDFExc(
                                qpdf_e_damaged_pdf,
                                input->getName(),
                                object_description,
                                offset,
                                "expected dictionary key but found"
                                " non-name object; inserting key " +
                                    candidate));
                        val = key_obj;
                        key_obj = newName(candidate);
                    } else if (i + 1 >= olist.size()) {
                        QTC::TC("qpdf", "QPDFObjectHandle no val for last key");
                        warn(
                            context,
                            QPDFExc(
                                qpdf_e_damaged_pdf,
                                input->getName(),
                                object_description,
                                offset,
                                "dictionary ended prematurely; "
                                "using null as value for last key"));
                        val = newNull();
                        setObjectDescriptionFromInput(
                            val, context, object_description, input, offset);
                    } else {
                        val = olist.at(++i);
                    }
                    std::string key = key_obj.getName();
                    if (dict.count(key) > 0) {
                        QTC::TC("qpdf", "QPDFObjectHandle duplicate dict key");
                        warn(
                            context,
                            QPDFExc(
                                qpdf_e_damaged_pdf,
                                input->getName(),
                                object_description,
                                offset,
                                "dictionary has duplicated key " + key +
                                    "; last occurrence overrides earlier "
                                    "ones"));
                    }
                    dict[key] = val;
                }
                if (!contents_string.empty() && dict.count("/Type") &&
                    dict["/Type"].isNameAndEquals("/Sig") &&
                    dict.count("/ByteRange") && dict.count("/Contents") &&
                    dict["/Contents"].isString()) {
                    dict["/Contents"] =
                        QPDFObjectHandle::newString(contents_string);
                    dict["/Contents"].setParsedOffset(contents_offset);
                }
                object = newDictionary(dict);
                setObjectDescriptionFromInput(
                    object, context, object_description, input, offset);
                // The `offset` points to the next of "<<". Set the
                // rewind offset to point to the beginning of "<<".
                // This has been explicitly tested with whitespace
                // surrounding the dictionary start delimiter.
                // getLastOffset points to the dictionary end token
                // and therefore can't be used here.
                object.setParsedOffset(offset - 2);
                set_offset = true;
            }
            olist_stack.pop_back();
            offset_stack.pop_back();
            if (state_stack.back() == st_top) {
                done = true;
            } else {
                olist_stack.back().append(object);
            }
            contents_string_stack.pop_back();
            contents_offset_stack.pop_back();
        }
    }

    if (!set_offset) {
        setObjectDescriptionFromInput(
            object, context, object_description, input, offset);
        object.setParsedOffset(offset);
    }
    return object;
}

qpdf_offset_t
QPDFObjectHandle::getParsedOffset()
{
    dereference();
    return this->obj->getParsedOffset();
}

void
QPDFObjectHandle::setParsedOffset(qpdf_offset_t offset)
{
    // This is called during parsing on newly created direct objects,
    // so we can't call dereference() here.
    if (this->obj.get()) {
        this->obj->setParsedOffset(offset);
    }
}

QPDFObjectHandle
QPDFObjectHandle::newIndirect(QPDF* qpdf, int objid, int generation)
{
    if (objid == 0) {
        // Special case: QPDF uses objid 0 as a sentinel for direct
        // objects, and the PDF specification doesn't allow for object
        // 0. Treat indirect references to object 0 as null so that we
        // never create an indirect object with objid 0.
        QTC::TC("qpdf", "QPDFObjectHandle indirect with 0 objid");
        return newNull();
    }

    return QPDFObjectHandle(qpdf, objid, generation);
}

QPDFObjectHandle
QPDFObjectHandle::newBool(bool value)
{
    return QPDFObjectHandle(new QPDF_Bool(value));
}

QPDFObjectHandle
QPDFObjectHandle::newNull()
{
    return QPDFObjectHandle(new QPDF_Null());
}

QPDFObjectHandle
QPDFObjectHandle::newInteger(long long value)
{
    return QPDFObjectHandle(new QPDF_Integer(value));
}

QPDFObjectHandle
QPDFObjectHandle::newReal(std::string const& value)
{
    return QPDFObjectHandle(new QPDF_Real(value));
}

QPDFObjectHandle
QPDFObjectHandle::newReal(
    double value, int decimal_places, bool trim_trailing_zeroes)
{
    return QPDFObjectHandle(
        new QPDF_Real(value, decimal_places, trim_trailing_zeroes));
}

QPDFObjectHandle
QPDFObjectHandle::newName(std::string const& name)
{
    return QPDFObjectHandle(new QPDF_Name(name));
}

QPDFObjectHandle
QPDFObjectHandle::newString(std::string const& str)
{
    return QPDFObjectHandle(new QPDF_String(str));
}

QPDFObjectHandle
QPDFObjectHandle::newUnicodeString(std::string const& utf8_str)
{
    return QPDFObjectHandle(QPDF_String::new_utf16(utf8_str));
}

QPDFObjectHandle
QPDFObjectHandle::newOperator(std::string const& value)
{
    return QPDFObjectHandle(new QPDF_Operator(value));
}

QPDFObjectHandle
QPDFObjectHandle::newInlineImage(std::string const& value)
{
    return QPDFObjectHandle(new QPDF_InlineImage(value));
}

QPDFObjectHandle
QPDFObjectHandle::newArray()
{
    return newArray(std::vector<QPDFObjectHandle>());
}

QPDFObjectHandle
QPDFObjectHandle::newArray(std::vector<QPDFObjectHandle> const& items)
{
    return QPDFObjectHandle(new QPDF_Array(items));
}

QPDFObjectHandle
QPDFObjectHandle::newArray(Rectangle const& rect)
{
    std::vector<QPDFObjectHandle> items;
    items.push_back(newReal(rect.llx));
    items.push_back(newReal(rect.lly));
    items.push_back(newReal(rect.urx));
    items.push_back(newReal(rect.ury));
    return newArray(items);
}

QPDFObjectHandle
QPDFObjectHandle::newArray(Matrix const& matrix)
{
    std::vector<QPDFObjectHandle> items;
    items.push_back(newReal(matrix.a));
    items.push_back(newReal(matrix.b));
    items.push_back(newReal(matrix.c));
    items.push_back(newReal(matrix.d));
    items.push_back(newReal(matrix.e));
    items.push_back(newReal(matrix.f));
    return newArray(items);
}

QPDFObjectHandle
QPDFObjectHandle::newArray(QPDFMatrix const& matrix)
{
    std::vector<QPDFObjectHandle> items;
    items.push_back(newReal(matrix.a));
    items.push_back(newReal(matrix.b));
    items.push_back(newReal(matrix.c));
    items.push_back(newReal(matrix.d));
    items.push_back(newReal(matrix.e));
    items.push_back(newReal(matrix.f));
    return newArray(items);
}

QPDFObjectHandle
QPDFObjectHandle::newFromRectangle(Rectangle const& rect)
{
    return newArray(rect);
}

QPDFObjectHandle
QPDFObjectHandle::newFromMatrix(Matrix const& m)
{
    return newArray(m);
}

QPDFObjectHandle
QPDFObjectHandle::newFromMatrix(QPDFMatrix const& m)
{
    return newArray(m);
}

QPDFObjectHandle
QPDFObjectHandle::newDictionary()
{
    return newDictionary(std::map<std::string, QPDFObjectHandle>());
}

QPDFObjectHandle
QPDFObjectHandle::newDictionary(
    std::map<std::string, QPDFObjectHandle> const& items)
{
    return QPDFObjectHandle(new QPDF_Dictionary(items));
}

QPDFObjectHandle
QPDFObjectHandle::newStream(
    QPDF* qpdf,
    int objid,
    int generation,
    QPDFObjectHandle stream_dict,
    qpdf_offset_t offset,
    size_t length)
{
    QPDFObjectHandle result = QPDFObjectHandle(
        new QPDF_Stream(qpdf, objid, generation, stream_dict, offset, length));
    if (offset) {
        result.setParsedOffset(offset);
    }
    return result;
}

QPDFObjectHandle
QPDFObjectHandle::newStream(QPDF* qpdf)
{
    if (qpdf == 0) {
        throw std::runtime_error(
            "attempt to create stream in null qpdf object");
    }
    QTC::TC("qpdf", "QPDFObjectHandle newStream");
    QPDFObjectHandle stream_dict = newDictionary();
    QPDFObjectHandle result = qpdf->makeIndirectObject(
        QPDFObjectHandle(new QPDF_Stream(qpdf, 0, 0, stream_dict, 0, 0)));
    result.dereference();
    QPDF_Stream* stream = dynamic_cast<QPDF_Stream*>(result.obj.get());
    stream->setObjGen(result.getObjectID(), result.getGeneration());
    return result;
}

QPDFObjectHandle
QPDFObjectHandle::newStream(QPDF* qpdf, std::shared_ptr<Buffer> data)
{
    QTC::TC("qpdf", "QPDFObjectHandle newStream with data");
    QPDFObjectHandle result = newStream(qpdf);
    result.replaceStreamData(data, newNull(), newNull());
    return result;
}

QPDFObjectHandle
QPDFObjectHandle::newStream(QPDF* qpdf, std::string const& data)
{
    QTC::TC("qpdf", "QPDFObjectHandle newStream with string");
    QPDFObjectHandle result = newStream(qpdf);
    result.replaceStreamData(data, newNull(), newNull());
    return result;
}

QPDFObjectHandle
QPDFObjectHandle::newReserved(QPDF* qpdf)
{
    // Reserve a spot for this object by assigning it an object
    // number, but then return an unresolved handle to the object.
    QPDFObjectHandle reserved =
        qpdf->makeIndirectObject(QPDFObjectHandle(new QPDF_Reserved()));
    QPDFObjectHandle result =
        newIndirect(qpdf, reserved.objid, reserved.generation);
    result.reserved = true;
    return result;
}

void
QPDFObjectHandle::setObjectDescription(
    QPDF* owning_qpdf, std::string const& object_description)
{
    // This is called during parsing on newly created direct objects,
    // so we can't call dereference() here.
    if (isInitialized() && this->obj.get()) {
        this->obj->setDescription(owning_qpdf, object_description);
    }
}

bool
QPDFObjectHandle::hasObjectDescription()
{
    if (isInitialized()) {
        dereference();
        if (this->obj.get()) {
            return this->obj->hasDescription();
        }
    }
    return false;
}

QPDFObjectHandle
QPDFObjectHandle::shallowCopy()
{
    QPDFObjectHandle result;
    shallowCopyInternal(result, false);
    return result;
}

QPDFObjectHandle
QPDFObjectHandle::unsafeShallowCopy()
{
    QPDFObjectHandle result;
    shallowCopyInternal(result, true);
    return result;
}

void
QPDFObjectHandle::shallowCopyInternal(
    QPDFObjectHandle& new_obj, bool first_level_only)
{
    assertInitialized();

    if (isStream()) {
        QTC::TC("qpdf", "QPDFObjectHandle ERR shallow copy stream");
        throw std::runtime_error("attempt to make a shallow copy of a stream");
    }

    if (isArray()) {
        QTC::TC("qpdf", "QPDFObjectHandle shallow copy array");
        // No newArray for shallow copying the sparse array
        QPDF_Array* arr = dynamic_cast<QPDF_Array*>(obj.get());
        new_obj =
            QPDFObjectHandle(new QPDF_Array(arr->getElementsForShallowCopy()));
    } else if (isDictionary()) {
        QTC::TC("qpdf", "QPDFObjectHandle shallow copy dictionary");
        new_obj = newDictionary(getDictAsMap());
    } else {
        QTC::TC("qpdf", "QPDFObjectHandle shallow copy scalar");
        new_obj = *this;
    }

    std::set<QPDFObjGen> visited;
    new_obj.copyObject(visited, false, first_level_only, false);
}

void
QPDFObjectHandle::copyObject(
    std::set<QPDFObjGen>& visited,
    bool cross_indirect,
    bool first_level_only,
    bool stop_at_streams)
{
    assertInitialized();

    if (isStream()) {
        QTC::TC(
            "qpdf", "QPDFObjectHandle copy stream", stop_at_streams ? 0 : 1);
        if (stop_at_streams) {
            return;
        }
        throw std::runtime_error(
            "attempt to make a stream into a direct object");
    }

    QPDFObjGen cur_og(this->objid, this->generation);
    if (cur_og.getObj() != 0) {
        if (visited.count(cur_og)) {
            QTC::TC("qpdf", "QPDFObjectHandle makeDirect loop");
            throw std::runtime_error(
                "loop detected while converting object from "
                "indirect to direct");
        }
        visited.insert(cur_og);
    }

    if (isReserved()) {
        throw std::logic_error("QPDFObjectHandle: attempting to make a"
                               " reserved object handle direct");
    }

    dereference();
    this->qpdf = 0;
    this->objid = 0;
    this->generation = 0;

    std::shared_ptr<QPDFObject> new_obj;

    if (isBool()) {
        QTC::TC("qpdf", "QPDFObjectHandle clone bool");
        new_obj = std::shared_ptr<QPDFObject>(new QPDF_Bool(getBoolValue()));
    } else if (isNull()) {
        QTC::TC("qpdf", "QPDFObjectHandle clone null");
        new_obj = std::shared_ptr<QPDFObject>(new QPDF_Null());
    } else if (isInteger()) {
        QTC::TC("qpdf", "QPDFObjectHandle clone integer");
        new_obj = std::shared_ptr<QPDFObject>(new QPDF_Integer(getIntValue()));
    } else if (isReal()) {
        QTC::TC("qpdf", "QPDFObjectHandle clone real");
        new_obj = std::shared_ptr<QPDFObject>(new QPDF_Real(getRealValue()));
    } else if (isName()) {
        QTC::TC("qpdf", "QPDFObjectHandle clone name");
        new_obj = std::shared_ptr<QPDFObject>(new QPDF_Name(getName()));
    } else if (isString()) {
        QTC::TC("qpdf", "QPDFObjectHandle clone string");
        new_obj =
            std::shared_ptr<QPDFObject>(new QPDF_String(getStringValue()));
    } else if (isArray()) {
        QTC::TC("qpdf", "QPDFObjectHandle clone array");
        std::vector<QPDFObjectHandle> items;
        int n = getArrayNItems();
        for (int i = 0; i < n; ++i) {
            items.push_back(getArrayItem(i));
            if ((!first_level_only) &&
                (cross_indirect || (!items.back().isIndirect()))) {
                items.back().copyObject(
                    visited, cross_indirect, first_level_only, stop_at_streams);
            }
        }
        new_obj = std::shared_ptr<QPDFObject>(new QPDF_Array(items));
    } else if (isDictionary()) {
        QTC::TC("qpdf", "QPDFObjectHandle clone dictionary");
        std::set<std::string> keys = getKeys();
        std::map<std::string, QPDFObjectHandle> items;
        for (auto const& key: keys) {
            items[key] = getKey(key);
            if ((!first_level_only) &&
                (cross_indirect || (!items[key].isIndirect()))) {
                items[key].copyObject(
                    visited, cross_indirect, first_level_only, stop_at_streams);
            }
        }
        new_obj = std::shared_ptr<QPDFObject>(new QPDF_Dictionary(items));
    } else {
        throw std::logic_error("QPDFObjectHandle::makeDirectInternal: "
                               "unknown object type");
    }

    this->obj = new_obj;

    if (cur_og.getObj()) {
        visited.erase(cur_og);
    }
}

QPDFObjectHandle
QPDFObjectHandle::copyStream()
{
    assertStream();
    QPDFObjectHandle result = newStream(this->getOwningQPDF());
    QPDFObjectHandle dict = result.getDict();
    QPDFObjectHandle old_dict = getDict();
    for (auto& iter: QPDFDictItems(old_dict)) {
        if (iter.second.isIndirect()) {
            dict.replaceKey(iter.first, iter.second);
        } else {
            dict.replaceKey(iter.first, iter.second.shallowCopy());
        }
    }
    QPDF::StreamCopier::copyStreamData(getOwningQPDF(), result, *this);
    return result;
}

void
QPDFObjectHandle::makeDirect(bool allow_streams)
{
    std::set<QPDFObjGen> visited;
    copyObject(visited, true, false, allow_streams);
}

void
QPDFObjectHandle::assertInitialized() const
{
    if (!this->initialized) {
        throw std::logic_error("operation attempted on uninitialized "
                               "QPDFObjectHandle");
    }
}

void
QPDFObjectHandle::typeWarning(
    char const* expected_type, std::string const& warning)
{
    QPDF* context = nullptr;
    std::string description;
    dereference();
    this->obj->getDescription(context, description);
    // Null context handled by warn
    warn(
        context,
        QPDFExc(
            qpdf_e_object,
            "",
            description,
            0,
            std::string("operation for ") + expected_type +
                " attempted on object of type " + getTypeName() + ": " +
                warning));
}

void
QPDFObjectHandle::warnIfPossible(
    std::string const& warning, bool throw_if_no_description)
{
    QPDF* context = 0;
    std::string description;
    dereference();
    if (this->obj->getDescription(context, description)) {
        warn(context, QPDFExc(qpdf_e_damaged_pdf, "", description, 0, warning));
    } else if (throw_if_no_description) {
        throw std::runtime_error(warning);
    }
}

void
QPDFObjectHandle::objectWarning(std::string const& warning)
{
    QPDF* context = nullptr;
    std::string description;
    dereference();
    this->obj->getDescription(context, description);
    // Null context handled by warn
    warn(context, QPDFExc(qpdf_e_object, "", description, 0, warning));
}

void
QPDFObjectHandle::assertType(char const* type_name, bool istype)
{
    if (!istype) {
        throw std::runtime_error(
            std::string("operation for ") + type_name +
            " attempted on object of type " + getTypeName());
    }
}

void
QPDFObjectHandle::assertNull()
{
    assertType("null", isNull());
}

void
QPDFObjectHandle::assertBool()
{
    assertType("boolean", isBool());
}

void
QPDFObjectHandle::assertInteger()
{
    assertType("integer", isInteger());
}

void
QPDFObjectHandle::assertReal()
{
    assertType("real", isReal());
}

void
QPDFObjectHandle::assertName()
{
    assertType("name", isName());
}

void
QPDFObjectHandle::assertString()
{
    assertType("string", isString());
}

void
QPDFObjectHandle::assertOperator()
{
    assertType("operator", isOperator());
}

void
QPDFObjectHandle::assertInlineImage()
{
    assertType("inlineimage", isInlineImage());
}

void
QPDFObjectHandle::assertArray()
{
    assertType("array", isArray());
}

void
QPDFObjectHandle::assertDictionary()
{
    assertType("dictionary", isDictionary());
}

void
QPDFObjectHandle::assertStream()
{
    assertType("stream", isStream());
}

void
QPDFObjectHandle::assertReserved()
{
    assertType("reserved", isReserved());
}

void
QPDFObjectHandle::assertIndirect()
{
    if (!isIndirect()) {
        throw std::logic_error(
            "operation for indirect object attempted on direct object");
    }
}

void
QPDFObjectHandle::assertScalar()
{
    assertType("scalar", isScalar());
}

void
QPDFObjectHandle::assertNumber()
{
    assertType("number", isNumber());
}

bool
QPDFObjectHandle::isPageObject()
{
    // See comments in QPDFObjectHandle.hh.
    if (getOwningQPDF() == nullptr) {
        return false;
    }
    // getAllPages repairs /Type when traversing the page tree.
    getOwningQPDF()->getAllPages();
    if (!this->isDictionary()) {
        return false;
    }
    if (this->hasKey("/Type")) {
        QPDFObjectHandle type = this->getKey("/Type");
        if (type.isNameAndEquals("/Page")) {
            return true;
        }
        // Files have been seen in the wild that have /Type (Page)
        else if (type.isString() && (type.getStringValue() == "Page")) {
            return true;
        } else {
            return false;
        }
    }
    return false;
}

bool
QPDFObjectHandle::isPagesObject()
{
    if (getOwningQPDF() == nullptr) {
        return false;
    }
    // getAllPages repairs /Type when traversing the page tree.
    getOwningQPDF()->getAllPages();
    return isDictionaryOfType("/Pages");
}

bool
QPDFObjectHandle::isFormXObject()
{
    return isStreamOfType("", "/Form");
}

bool
QPDFObjectHandle::isImage(bool exclude_imagemask)
{
    return (
        isStreamOfType("", "/Image") &&
        ((!exclude_imagemask) ||
         (!(getDict().getKey("/ImageMask").isBool() &&
            getDict().getKey("/ImageMask").getBoolValue()))));
}

void
QPDFObjectHandle::checkOwnership(QPDFObjectHandle const& item) const
{
    if ((this->qpdf != nullptr) && (item.qpdf != nullptr) &&
        (this->qpdf != item.qpdf)) {
        QTC::TC("qpdf", "QPDFObjectHandle check ownership");
        throw std::logic_error(
            "Attempting to add an object from a different QPDF."
            " Use QPDF::copyForeignObject to add objects from another file.");
    }
}

void
QPDFObjectHandle::assertPageObject()
{
    if (!isPageObject()) {
        throw std::runtime_error("page operation called on non-Page object");
    }
}

void
QPDFObjectHandle::dereference()
{
    if (!this->initialized) {
        throw std::logic_error(
            "attempted to dereference an uninitialized QPDFObjectHandle");
    }
    if (this->obj.get() && this->objid &&
        QPDF::Resolver::objectChanged(
            this->qpdf, QPDFObjGen(this->objid, this->generation), this->obj)) {
        this->obj = nullptr;
    }
    if (this->obj.get() == 0) {
        std::shared_ptr<QPDFObject> obj =
            QPDF::Resolver::resolve(this->qpdf, this->objid, this->generation);
        if (obj.get() == 0) {
            // QPDF::resolve never returns an uninitialized object, but
            // check just in case.
            this->obj = std::shared_ptr<QPDFObject>(new QPDF_Null());
        } else if (dynamic_cast<QPDF_Reserved*>(obj.get())) {
            // Do not resolve
        } else {
            this->reserved = false;
            this->obj = obj;
        }
    }
}

void
QPDFObjectHandle::warn(QPDF* qpdf, QPDFExc const& e)
{
    // If parsing on behalf of a QPDF object and want to give a
    // warning, we can warn through the object. If parsing for some
    // other reason, such as an explicit creation of an object from a
    // string, then just throw the exception.
    if (qpdf) {
        qpdf->warn(e);
    } else {
        throw e;
    }
}

QPDFObjectHandle::QPDFDictItems::QPDFDictItems(QPDFObjectHandle const& oh) :
    oh(oh)
{
}

QPDFObjectHandle::QPDFDictItems::iterator&
QPDFObjectHandle::QPDFDictItems::iterator::operator++()
{
    ++this->m->iter;
    updateIValue();
    return *this;
}

QPDFObjectHandle::QPDFDictItems::iterator&
QPDFObjectHandle::QPDFDictItems::iterator::operator--()
{
    --this->m->iter;
    updateIValue();
    return *this;
}

QPDFObjectHandle::QPDFDictItems::iterator::reference
QPDFObjectHandle::QPDFDictItems::iterator::operator*()
{
    updateIValue();
    return this->ivalue;
}

QPDFObjectHandle::QPDFDictItems::iterator::pointer
QPDFObjectHandle::QPDFDictItems::iterator::operator->()
{
    updateIValue();
    return &this->ivalue;
}

bool
QPDFObjectHandle::QPDFDictItems::iterator::operator==(
    iterator const& other) const
{
    if (this->m->is_end && other.m->is_end) {
        return true;
    }
    if (this->m->is_end || other.m->is_end) {
        return false;
    }
    return (this->ivalue.first == other.ivalue.first);
}

QPDFObjectHandle::QPDFDictItems::iterator::iterator(
    QPDFObjectHandle& oh, bool for_begin) :
    m(new Members(oh, for_begin))
{
    updateIValue();
}

void
QPDFObjectHandle::QPDFDictItems::iterator::updateIValue()
{
    this->m->is_end = (this->m->iter == this->m->keys.end());
    if (this->m->is_end) {
        this->ivalue.first = "";
        this->ivalue.second = QPDFObjectHandle();
    } else {
        this->ivalue.first = *(this->m->iter);
        this->ivalue.second = this->m->oh.getKey(this->ivalue.first);
    }
}

QPDFObjectHandle::QPDFDictItems::iterator::Members::Members(
    QPDFObjectHandle& oh, bool for_begin) :
    oh(oh)
{
    this->keys = oh.getKeys();
    this->iter = for_begin ? this->keys.begin() : this->keys.end();
}

QPDFObjectHandle::QPDFDictItems::iterator
QPDFObjectHandle::QPDFDictItems::begin()
{
    return iterator(oh, true);
}

QPDFObjectHandle::QPDFDictItems::iterator
QPDFObjectHandle::QPDFDictItems::end()
{
    return iterator(oh, false);
}

QPDFObjectHandle::QPDFArrayItems::QPDFArrayItems(QPDFObjectHandle const& oh) :
    oh(oh)
{
}

QPDFObjectHandle::QPDFArrayItems::iterator&
QPDFObjectHandle::QPDFArrayItems::iterator::operator++()
{
    if (!this->m->is_end) {
        ++this->m->item_number;
        updateIValue();
    }
    return *this;
}

QPDFObjectHandle::QPDFArrayItems::iterator&
QPDFObjectHandle::QPDFArrayItems::iterator::operator--()
{
    if (this->m->item_number > 0) {
        --this->m->item_number;
        updateIValue();
    }
    return *this;
}

QPDFObjectHandle::QPDFArrayItems::iterator::reference
QPDFObjectHandle::QPDFArrayItems::iterator::operator*()
{
    updateIValue();
    return this->ivalue;
}

QPDFObjectHandle::QPDFArrayItems::iterator::pointer
QPDFObjectHandle::QPDFArrayItems::iterator::operator->()
{
    updateIValue();
    return &this->ivalue;
}

bool
QPDFObjectHandle::QPDFArrayItems::iterator::operator==(
    iterator const& other) const
{
    return (this->m->item_number == other.m->item_number);
}

QPDFObjectHandle::QPDFArrayItems::iterator::iterator(
    QPDFObjectHandle& oh, bool for_begin) :
    m(new Members(oh, for_begin))
{
    updateIValue();
}

void
QPDFObjectHandle::QPDFArrayItems::iterator::updateIValue()
{
    this->m->is_end = (this->m->item_number >= this->m->oh.getArrayNItems());
    if (this->m->is_end) {
        this->ivalue = QPDFObjectHandle();
    } else {
        this->ivalue = this->m->oh.getArrayItem(this->m->item_number);
    }
}

QPDFObjectHandle::QPDFArrayItems::iterator::Members::Members(
    QPDFObjectHandle& oh, bool for_begin) :
    oh(oh)
{
    this->item_number = for_begin ? 0 : oh.getArrayNItems();
}

QPDFObjectHandle::QPDFArrayItems::iterator
QPDFObjectHandle::QPDFArrayItems::begin()
{
    return iterator(oh, true);
}

QPDFObjectHandle::QPDFArrayItems::iterator
QPDFObjectHandle::QPDFArrayItems::end()
{
    return iterator(oh, false);
}

QPDFObjectHandle operator""_qpdf(char const* v, size_t len)
{
    return QPDFObjectHandle::parse(
        std::string(v, len), "QPDFObjectHandle literal");
}