[Libreoffice-commits] core.git: vcl/source

[Caolán McNamara (via logerrit)]

 vcl/source/filter/GraphicFormatDetector.cxx |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

New commits:
commit fa387c3a99ebd033586b6f0a45276016dda56b45
Author:     Caolán McNamara <caolanm at redhat.com>
AuthorDate: Fri Sep 3 10:38:14 2021 +0100
Commit:     Caolán McNamara <caolanm at redhat.com>
CommitDate: Fri Sep 3 20:58:56 2021 +0200

    ofz: MemorySanitizer: use-of-uninitialized-value
    
    Change-Id: I6bafceac5ebd1852aaf296abe89b49b74ad884d5
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/121598
    Tested-by: Jenkins
    Reviewed-by: Caolán McNamara <caolanm at redhat.com>

diff --git a/vcl/source/filter/GraphicFormatDetector.cxx b/vcl/source/filter/GraphicFormatDetector.cxx
index dafe7f5222b4..6c8df32a456e 100644
--- a/vcl/source/filter/GraphicFormatDetector.cxx
+++ b/vcl/source/filter/GraphicFormatDetector.cxx
@@ -700,7 +700,9 @@ bool GraphicFormatDetector::checkSVG()
         ZCodec aCodec;
         mrStream.Seek(mnStreamPosition);
         aCodec.BeginCompression(ZCODEC_DEFAULT_COMPRESSION, /*gzLib*/ true);
-        nDecompressedSize = aCodec.Read(mrStream, sExtendedOrDecompressedFirstBytes, 2048);
+        auto nDecompressedOut = aCodec.Read(mrStream, sExtendedOrDecompressedFirstBytes, 2048);
+        // ZCodec::Decompress returns -1 on failure
+        nDecompressedSize = nDecompressedOut < 0 ? 0 : nDecompressedOut;
         nCheckSize = std::min<sal_uInt64>(nDecompressedSize, 256);
         aCodec.EndCompression();
         pCheckArray = sExtendedOrDecompressedFirstBytes;