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Remove redundant parameters from QPDF::readObject

This commit is contained in:
m-holger 2023-07-07 20:37:13 +01:00
parent 2bf7359e35
commit bee726609c
2 changed files with 30 additions and 44 deletions
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6
include/qpdf/QPDF.hh
View File

@ -1006,11 +1006,7 @@ class QPDF
void insertFreeXrefEntry(QPDFObjGen);
void insertReconstructedXrefEntry(int obj, qpdf_offset_t f1, int f2);
void setLastObjectDescription(std::string const& description, QPDFObjGen const& og);
QPDFObjectHandle readObject(
std::shared_ptr<InputSource>,
std::string const& description,
QPDFObjGen const& og,
bool in_object_stream);
QPDFObjectHandle readObject(std::string const& description, QPDFObjGen og);
QPDFObjectHandle readObjectInStream(std::shared_ptr<InputSource>, QPDFObjGen og);
size_t recoverStreamLength(
std::shared_ptr<InputSource> input, QPDFObjGen const& og, qpdf_offset_t stream_offset);

68
libqpdf/QPDF.cc
View File

@ -567,7 +567,7 @@ QPDF::reconstruct_xref(QPDFExc& e)
insertReconstructedXrefEntry(obj, token_start, gen);
}
} else if (!m->trailer.isInitialized() && t1.isWord("trailer")) {
QPDFObjectHandle t = readObject(m->file, "trailer", QPDFObjGen(), false);
QPDFObjectHandle t = readObject("trailer", QPDFObjGen());
if (!t.isDictionary()) {
// Oh well. It was worth a try.
} else {
@ -855,7 +855,7 @@ QPDF::read_xrefTable(qpdf_offset_t xref_offset)
}
// Set offset to previous xref table if any
QPDFObjectHandle cur_trailer = readObject(m->file, "trailer", QPDFObjGen(), false);
QPDFObjectHandle cur_trailer = readObject("trailer", QPDFObjGen());
if (!cur_trailer.isDictionary()) {
QTC::TC("qpdf", "QPDF missing trailer");
throw damagedPDF("", "expected trailer dictionary");
@ -1268,32 +1268,28 @@ QPDF::setLastObjectDescription(std::string const& description, QPDFObjGen const&
}
QPDFObjectHandle
QPDF::readObject(
std::shared_ptr<InputSource> input,
std::string const& description,
QPDFObjGen const& og,
bool in_object_stream)
QPDF::readObject(std::string const& description, QPDFObjGen og)
{
setLastObjectDescription(description, og);
qpdf_offset_t offset = input->tell();
qpdf_offset_t offset = m->file->tell();
bool empty = false;
std::shared_ptr<StringDecrypter> decrypter_ph;
StringDecrypter* decrypter = nullptr;
if (m->encp->encrypted && (!in_object_stream)) {
if (m->encp->encrypted) {
decrypter_ph = std::make_shared<StringDecrypter>(this, og);
decrypter = decrypter_ph.get();
}
auto object = QPDFParser(input, m->last_object_description, m->tokenizer, decrypter, this)
auto object = QPDFParser(m->file, m->last_object_description, m->tokenizer, decrypter, this)
.parse(empty, false);
if (empty) {
// Nothing in the PDF spec appears to allow empty objects, but they have been encountered in
// actual PDF files and Adobe Reader appears to ignore them.
warn(damagedPDF(input, input->getLastOffset(), "empty object treated as null"));
} else if (object.isDictionary() && (!in_object_stream)) {
warn(damagedPDF(m->file, m->file->getLastOffset(), "empty object treated as null"));
} else if (object.isDictionary()) {
// check for stream
qpdf_offset_t cur_offset = input->tell();
if (readToken(input).isWord("stream")) {
qpdf_offset_t cur_offset = m->file->tell();
if (readToken(m->file).isWord("stream")) {
// The PDF specification states that the word "stream" should be followed by either a
// carriage return and a newline or by a newline alone. It specifically disallowed
// following it by a carriage return alone since, in that case, there would be no way to
@ -1305,7 +1301,7 @@ QPDF::readObject(
while (!done) {
done = true;
char ch;
if (input->read(&ch, 1) == 0) {
if (m->file->read(&ch, 1) == 0) {
// A premature EOF here will result in some other problem that will get reported
// at another time.
} else if (ch == '\n') {
@ -1313,7 +1309,7 @@ QPDF::readObject(
QTC::TC("qpdf", "QPDF stream with NL only");
} else if (ch == '\r') {
// Read another character
if (input->read(&ch, 1) != 0) {
if (m->file->read(&ch, 1) != 0) {
if (ch == '\n') {
// Ready to read stream data
QTC::TC("qpdf", "QPDF stream with CRNL");
@ -1321,32 +1317,27 @@ QPDF::readObject(
// Treat the \r by itself as the whitespace after endstream and start
// reading stream data in spite of not having seen a newline.
QTC::TC("qpdf", "QPDF stream with CR only");
input->unreadCh(ch);
m->file->unreadCh(ch);
warn(damagedPDF(
input,
input->tell(),
"stream keyword followed by carriage return "
"only"));
m->file->tell(),
"stream keyword followed by carriage return only"));
}
}
} else if (QUtil::is_space(ch)) {
warn(damagedPDF(
input, input->tell(), "stream keyword followed by extraneous whitespace"));
m->file->tell(), "stream keyword followed by extraneous whitespace"));
done = false;
} else {
QTC::TC("qpdf", "QPDF stream without newline");
input->unreadCh(ch);
m->file->unreadCh(ch);
warn(damagedPDF(
input,
input->tell(),
"stream keyword not followed by proper line "
"terminator"));
m->file->tell(), "stream keyword not followed by proper line terminator"));
}
}
// Must get offset before accessing any additional objects since resolving a previously
// unresolved indirect object will change file position.
qpdf_offset_t stream_offset = input->tell();
qpdf_offset_t stream_offset = m->file->tell();
size_t length = 0;
try {
@ -1355,37 +1346,36 @@ QPDF::readObject(
if (!length_obj.isInteger()) {
if (length_obj.isNull()) {
QTC::TC("qpdf", "QPDF stream without length");
throw damagedPDF(input, offset, "stream dictionary lacks /Length key");
throw damagedPDF(offset, "stream dictionary lacks /Length key");
}
QTC::TC("qpdf", "QPDF stream length not integer");
throw damagedPDF(
input, offset, "/Length key in stream dictionary is not an integer");
throw damagedPDF(offset, "/Length key in stream dictionary is not an integer");
}
length = toS(length_obj.getUIntValue());
// Seek in two steps to avoid potential integer overflow
input->seek(stream_offset, SEEK_SET);
input->seek(toO(length), SEEK_CUR);
if (!readToken(input).isWord("endstream")) {
m->file->seek(stream_offset, SEEK_SET);
m->file->seek(toO(length), SEEK_CUR);
if (!readToken(m->file).isWord("endstream")) {
QTC::TC("qpdf", "QPDF missing endstream");
throw damagedPDF(input, input->getLastOffset(), "expected endstream");
throw damagedPDF("expected endstream");
}
} catch (QPDFExc& e) {
if (m->attempt_recovery) {
warn(e);
length = recoverStreamLength(input, og, stream_offset);
length = recoverStreamLength(m->file, og, stream_offset);
} else {
throw;
}
}
object = newIndirect(og, QPDF_Stream::create(this, og, object, stream_offset, length));
} else {
input->seek(cur_offset, SEEK_SET);
m->file->seek(cur_offset, SEEK_SET);
}
}
// Override last_offset so that it points to the beginning of the object we just read
input->setLastOffset(offset);
m->file->setLastOffset(offset);
return object;
}
@ -1579,7 +1569,7 @@ QPDF::readObjectAtOffset(
}
}
QPDFObjectHandle oh = readObject(m->file, description, og, false);
QPDFObjectHandle oh = readObject(description, og);
if (!readToken(m->file).isWord("endobj")) {
QTC::TC("qpdf", "QPDF err expected endobj");