Replace containers of PointerHolder with containers of std::shared_ptr

None of these are in the public API.

examples/pdf-create.cc

@@ -16,6 +16,7 @@
 #include <qpdf/Pl_DCT.hh>
 #include <qpdf/QIntC.hh>
 #include <iostream>
+#include <memory>
 #include <string.h>
 #include <stdlib.h>
 
@@ -105,22 +106,25 @@ void
 ImageProvider::provideStreamData(int objid, int generation,
                                  Pipeline* pipeline)
 {
-    std::vector<PointerHolder<Pipeline> > to_delete;
+    std::vector<std::shared_ptr<Pipeline>> to_delete;
     Pipeline* p = pipeline;
+    std::shared_ptr<Pipeline> p_new;
 
     if (filter == "/DCTDecode")
     {
-        p = new Pl_DCT(
+        p_new = std::make_shared<Pl_DCT>(
             "image encoder", pipeline,
             QIntC::to_uint(width), QIntC::to_uint(getHeight()),
             QIntC::to_int(stripes[0].length()), j_color_space);
-        to_delete.push_back(p);
+        to_delete.push_back(p_new);
+        p = p_new.get();
     }
     else if (filter == "/RunLengthDecode")
     {
-        p = new Pl_RunLength(
+        p_new = std::make_shared<Pl_RunLength>(
             "image encoder", pipeline, Pl_RunLength::a_encode);
-        to_delete.push_back(p);
+        to_delete.push_back(p_new);
+        p = p_new.get();
     }
 
     for (size_t i = 0; i < n_stripes; ++i)

include/qpdf/QPDF.hh

@@ -1024,7 +1024,7 @@ class QPDF
         QPDF& qpdf_for_warning, Pipeline*& pipeline,
         int objid, int generation,
 	QPDFObjectHandle& stream_dict,
-	std::vector<PointerHolder<Pipeline> >& heap);
+	std::vector<std::shared_ptr<Pipeline>>& heap);
 
     // Methods to support object copying
     void reserveObjects(QPDFObjectHandle foreign, ObjCopier& obj_copier,

include/qpdf/QPDFWriter.hh

@@ -35,6 +35,7 @@
 #include <vector>
 #include <set>
 #include <map>
+#include <memory>
 
 #include <qpdf/Constants.h>
 
@@ -684,7 +685,7 @@ class QPDFWriter
         std::string extra_header_text;
         int encryption_dict_objid;
         std::string cur_data_key;
-        std::list<PointerHolder<Pipeline> > to_delete;
+        std::list<std::shared_ptr<Pipeline>> to_delete;
         Pl_Count* pipeline;
         std::list<QPDFObjectHandle> object_queue;
         std::map<QPDFObjGen, int> obj_renumber;

libqpdf/QPDF.cc

@@ -2910,7 +2910,7 @@ QPDF::pipeStreamData(PointerHolder<EncryptionParameters> encp,
                      bool suppress_warnings,
                      bool will_retry)
 {
-    std::vector<PointerHolder<Pipeline> > to_delete;
+    std::vector<std::shared_ptr<Pipeline>> to_delete;
     if (encp->encrypted)
     {
 	decryptStream(encp, file, qpdf_for_warning,

libqpdf/QPDFWriter.cc

@@ -132,9 +132,10 @@ QPDFWriter::setOutputFile(char const* description, FILE* file, bool close_file)
     this->m->filename = description;
     this->m->file = file;
     this->m->close_file = close_file;
-    Pipeline* p = new Pl_StdioFile("qpdf output", file);
+    std::shared_ptr<Pipeline> p = std::make_shared<Pl_StdioFile>(
+        "qpdf output", file);
     this->m->to_delete.push_back(p);
-    initializePipelineStack(p);
+    initializePipelineStack(p.get());
 }
 
 void
@@ -142,7 +143,8 @@ QPDFWriter::setOutputMemory()
 {
     this->m->filename = "memory buffer";
     this->m->buffer_pipeline = new Pl_Buffer("qpdf output");
-    this->m->to_delete.push_back(this->m->buffer_pipeline);
+    this->m->to_delete.push_back(
+        std::shared_ptr<Pipeline>(this->m->buffer_pipeline));
     initializePipelineStack(this->m->buffer_pipeline);
 }
 
@@ -1051,7 +1053,8 @@ void
 QPDFWriter::initializePipelineStack(Pipeline *p)
 {
     this->m->pipeline = new Pl_Count("pipeline stack base", p);
-    this->m->to_delete.push_back(this->m->pipeline);
+    this->m->to_delete.push_back(
+        std::shared_ptr<Pipeline>(this->m->pipeline));
     this->m->pipeline_stack.push_back(this->m->pipeline);
 }
 

libqpdf/QPDF_Stream.cc

@@ -463,34 +463,36 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline, bool* filterp,
     // create to be deleted when this function finishes. Pipelines
     // created by QPDFStreamFilter objects will be deleted by those
     // objects.
-    std::vector<PointerHolder<Pipeline>> to_delete;
+    std::vector<std::shared_ptr<Pipeline>> to_delete;
 
     PointerHolder<ContentNormalizer> normalizer;
+    std::shared_ptr<Pipeline> new_pipeline;
     if (filter)
     {
 	if (encode_flags & qpdf_ef_compress)
 	{
-	    pipeline = new Pl_Flate("compress stream", pipeline,
-				    Pl_Flate::a_deflate);
-	    to_delete.push_back(pipeline);
+	    new_pipeline = std::make_shared<Pl_Flate>(
+                "compress stream", pipeline, Pl_Flate::a_deflate);
+	    to_delete.push_back(new_pipeline);
+            pipeline = new_pipeline.get();
 	}
 
 	if (encode_flags & qpdf_ef_normalize)
 	{
             normalizer = new ContentNormalizer();
-	    pipeline = new Pl_QPDFTokenizer(
+	    new_pipeline = std::make_shared<Pl_QPDFTokenizer>(
                 "normalizer", normalizer.get(), pipeline);
-	    to_delete.push_back(pipeline);
+	    to_delete.push_back(new_pipeline);
+            pipeline = new_pipeline.get();
 	}
 
-        for (std::vector<PointerHolder<
-                 QPDFObjectHandle::TokenFilter> >::reverse_iterator iter =
-                 this->token_filters.rbegin();
+        for (auto iter = this->token_filters.rbegin();
              iter != this->token_filters.rend(); ++iter)
         {
-            pipeline = new Pl_QPDFTokenizer(
+            new_pipeline = std::make_shared<Pl_QPDFTokenizer>(
                 "token filter", (*iter).get(), pipeline);
-            to_delete.push_back(pipeline);
+            to_delete.push_back(new_pipeline);
+            pipeline = new_pipeline.get();
         }
 
 	for (auto f_iter = filters.rbegin();

libqpdf/QPDF_encryption.cc

@@ -1238,7 +1238,7 @@ QPDF::decryptStream(PointerHolder<EncryptionParameters> encp,
                     QPDF& qpdf_for_warning, Pipeline*& pipeline,
                     int objid, int generation,
 		    QPDFObjectHandle& stream_dict,
-		    std::vector<PointerHolder<Pipeline> >& heap)
+		    std::vector<std::shared_ptr<Pipeline>>& heap)
 {
     std::string type;
     if (stream_dict.getKey("/Type").isName())
@@ -1343,21 +1343,25 @@ QPDF::decryptStream(PointerHolder<EncryptionParameters> encp,
 	}
     }
     std::string key = getKeyForObject(encp, objid, generation, use_aes);
+    std::shared_ptr<Pipeline> new_pipeline;
     if (use_aes)
     {
 	QTC::TC("qpdf", "QPDF_encryption aes decode stream");
-	pipeline = new Pl_AES_PDF("AES stream decryption", pipeline,
-				  false, QUtil::unsigned_char_pointer(key),
-                                  key.length());
+	new_pipeline = std::make_shared<Pl_AES_PDF>(
+            "AES stream decryption", pipeline,
+            false, QUtil::unsigned_char_pointer(key),
+            key.length());
     }
     else
     {
 	QTC::TC("qpdf", "QPDF_encryption rc4 decode stream");
-	pipeline = new Pl_RC4("RC4 stream decryption", pipeline,
-			      QUtil::unsigned_char_pointer(key),
-                              toI(key.length()));
+	new_pipeline = std::make_shared<Pl_RC4>(
+            "RC4 stream decryption", pipeline,
+            QUtil::unsigned_char_pointer(key),
+            toI(key.length()));
     }
-    heap.push_back(pipeline);
+    pipeline = new_pipeline.get();
+    heap.push_back(new_pipeline);
 }
 
 void