From 0b77f2cf2646019331d3adc21985052319bdba4c Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Thu, 4 Mar 2021 15:40:56 -0500
Subject: [PATCH] Revert non-binary-compatible handleWarning change -- see TODO
 (ABI)

---
 ChangeLog                        |  4 ----
 TODO                             |  5 +++++
 include/qpdf/QPDFObjectHandle.hh | 11 +----------
 libqpdf/QPDFObjectHandle.cc      | 17 -----------------
 manual/qpdf-manual.xml           |  9 ---------
 5 files changed, 6 insertions(+), 40 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index be57346e..8f63349a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -51,10 +51,6 @@
 	bugs where it removes unreferenced resources that it isn't
 	supposed to.
 
-	* QPDFObjectHandle::ParserCallbacks: add virtual handleWarning
-	method, and provide default (empty) implementation of it and
-	handleEOF().
-
 	* Add QPDF::numWarnings() -- useful to tell whether any warnings
 	were issued by a specific bit of code.
 
diff --git a/TODO b/TODO
index e308927b..d327cc19 100644
--- a/TODO
+++ b/TODO
@@ -164,6 +164,11 @@ Comments appear in the code prefixed by "ABI"
 * Consider having addArrayItem, replaceKey, etc. return the new value
   so you can say
   auto oh = dict.replaceKey("/Key", QPDFObjectHandle::newSomething());
+* Added QPDFObjectHandle::ParserCallbacks::handleWarning but had to
+  revert because it was not binary compatible. Consider re-adding. The
+  commit that added this comment includes the reverting of the change.
+  The previous commit removes the code that was calling and using
+  handleWarning.
 
 Page splitting/merging
 ======================
diff --git a/include/qpdf/QPDFObjectHandle.hh b/include/qpdf/QPDFObjectHandle.hh
index 238dd6e3..e57179b5 100644
--- a/include/qpdf/QPDFObjectHandle.hh
+++ b/include/qpdf/QPDFObjectHandle.hh
@@ -224,16 +224,7 @@ class QPDFObjectHandle
         virtual void handleObject(
             QPDFObjectHandle, size_t offset, size_t length);
 
-        // handleWarning is called if a warning was issued during the
-        // parsing of the most recent object. There's no good way to
-        // get information about the warning, but implementors can use
-        // this to become aware that there was some problem while
-        // parsing this content stream.
-        QPDF_DLL
-        virtual void handleWarning();
-
-        QPDF_DLL
-        virtual void handleEOF();
+        virtual void handleEOF() = 0;
 
         // Override this if you want to know the full size of the
         // contents, possibly after concatenation of multiple streams.
diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc
index e7d84b4c..27740f09 100644
--- a/libqpdf/QPDFObjectHandle.cc
+++ b/libqpdf/QPDFObjectHandle.cc
@@ -151,16 +151,6 @@ QPDFObjectHandle::ParserCallbacks::handleObject(
     handleObject(oh);
 }
 
-void
-QPDFObjectHandle::ParserCallbacks::handleWarning()
-{
-}
-
-void
-QPDFObjectHandle::ParserCallbacks::handleEOF()
-{
-}
-
 void
 QPDFObjectHandle::ParserCallbacks::contentSize(size_t)
 {
@@ -1983,15 +1973,9 @@ QPDFObjectHandle::parseContentStream_data(
         tokenizer.readToken(input, "content", true);
         qpdf_offset_t offset = input->getLastOffset();
         input->seek(offset, SEEK_SET);
-        size_t before_nwarnings = (context ? context->numWarnings() : 0);
         QPDFObjectHandle obj =
             parseInternal(input, "content", tokenizer,
                           empty, 0, context, true);
-        size_t after_nwarnings = (context ? context->numWarnings() : 0);
-        if (after_nwarnings > before_nwarnings)
-        {
-            callbacks->handleWarning();
-        }
         if (! obj.isInitialized())
         {
             // EOF
@@ -2018,7 +2002,6 @@ QPDFObjectHandle::parseContentStream_data(
                      QPDFExc(qpdf_e_damaged_pdf, input->getName(),
                              "stream data", input->tell(),
                              "EOF found while reading inline image"));
-                callbacks->handleWarning();
             }
             else
             {
diff --git a/manual/qpdf-manual.xml b/manual/qpdf-manual.xml
index d6098563..59d4dfb3 100644
--- a/manual/qpdf-manual.xml
+++ b/manual/qpdf-manual.xml
@@ -5125,15 +5125,6 @@ print "\n";
           <filename>ChangeLog</filename> file for details.
          </para>
         </listitem>
-        <listitem>
-         <para>
-          The virtual method
-          <function>QPDFObjectHandle::ParserCallbacks::handleWarning</function>
-          is now called whenever a warning is encountered while
-          parsing a content stream. Prior to this, the caller had no
-          way to know if this had happened.
-         </para>
-        </listitem>
         <listitem>
          <para>
           The method <function>QPDF::numWarnings</function> was added