From 0f2ef5e85bce0d64683e8071151711f21fa3e052 Mon Sep 17 00:00:00 2001
From: m-holger <m-holger@kubitscheck.org>
Date: Thu, 25 May 2023 14:10:47 +0100
Subject: Add new Buffer method copy and deprecate copy constructor /
 assignment operator

Also fix accidental Buffer copy in Pl_LZWDecoder::addToTable.
---
 libqpdf/Buffer.cc        | 25 +++++++++++++++++++++++++
 libqpdf/Pl_LZWDecoder.cc |  2 +-
 2 files changed, 26 insertions(+), 1 deletion(-)

(limited to 'libqpdf')

diff --git a/libqpdf/Buffer.cc b/libqpdf/Buffer.cc
index ae04fbc8..3dddd5db 100644
--- a/libqpdf/Buffer.cc
+++ b/libqpdf/Buffer.cc
@@ -1,7 +1,20 @@
+#include <qpdf/assert_test.h>
+
 #include <qpdf/Buffer.hh>
 
 #include <cstring>
 
+bool test_mode = false;
+
+// During CI the Buffer copy constructor and copy assignment operator throw an assertion error to
+// detect their accidental use. Call setTestMode to surpress the assertion errors for testing of
+// copy construction and assignment.
+void
+Buffer::setTestMode() noexcept
+{
+    test_mode = true;
+}
+
 Buffer::Members::Members(size_t size, unsigned char* buf, bool own_memory) :
     own_memory(own_memory),
     size(size),
@@ -38,12 +51,14 @@ Buffer::Buffer(unsigned char* buf, size_t size) :
 
 Buffer::Buffer(Buffer const& rhs)
 {
+    assert(test_mode);
     copy(rhs);
 }
 
 Buffer&
 Buffer::operator=(Buffer const& rhs)
 {
+    assert(test_mode);
     copy(rhs);
     return *this;
 }
@@ -88,3 +103,13 @@ Buffer::getBuffer()
 {
     return m->buf;
 }
+
+Buffer
+Buffer::copy() const
+{
+    auto result = Buffer(m->size);
+    if (m->size) {
+        memcpy(result.m->buf, m->buf, m->size);
+    }
+    return result;
+}
diff --git a/libqpdf/Pl_LZWDecoder.cc b/libqpdf/Pl_LZWDecoder.cc
index 4ffcaa3f..9abb69cd 100644
--- a/libqpdf/Pl_LZWDecoder.cc
+++ b/libqpdf/Pl_LZWDecoder.cc
@@ -129,7 +129,7 @@ Pl_LZWDecoder::addToTable(unsigned char next)
     unsigned char* new_data = entry.getBuffer();
     memcpy(new_data, last_data, last_size);
     new_data[last_size] = next;
-    this->table.push_back(entry);
+    this->table.push_back(std::move(entry));
 }
 
 void
-- 
cgit v1.2.3-70-g09d2