[poppler] poppler/FlateEncoder.cc

[GitLab Mirror]

 poppler/FlateEncoder.cc |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

New commits:
commit c702589307896c7d6f5f4cfdf63535761ad1ad23
Author: Even Rouault <even.roua...@spatialys.com>
Date:   Wed Nov 24 16:14:24 2021 +0100

    FlateEncoder.cc: fix -Wzero-as-null-pointer-constant warnings
    
    Use nullptr instead of Z_NULL. zlib.h defines Z_NULL as 0, so using
    nullptr is safe now, and for the future, as zlib.h can't really
    change its definition to something that would be fundammentaly different
    from expressing a null pointer.

diff --git a/poppler/FlateEncoder.cc b/poppler/FlateEncoder.cc
index 316e531e..fa8d574b 100644
--- a/poppler/FlateEncoder.cc
+++ b/poppler/FlateEncoder.cc
@@ -24,9 +24,15 @@ FlateEncoder::FlateEncoder(Stream *strA) : FilterStream(strA)
     outBufPtr = outBufEnd = outBuf;
     inBufEof = outBufEof = false;
 
-    zlib_stream.zalloc = Z_NULL;
-    zlib_stream.zfree = Z_NULL;
-    zlib_stream.opaque = Z_NULL;
+    // We used to assign Z_NULL to the 3 following members of zlib_stream,
+    // but as Z_NULL is a #define to 0, using it triggers the
+    // -Wzero-as-null-pointer-constant warning.
+    // For safety, check that the Z_NULL definition is equivalent to
+    // 0 / null pointer.
+    static_assert(Z_NULL == 0);
+    zlib_stream.zalloc = nullptr;
+    zlib_stream.zfree = nullptr;
+    zlib_stream.opaque = nullptr;
 
     zlib_status = deflateInit(&zlib_stream, Z_DEFAULT_COMPRESSION);