v1: add a safety check assert

git-svn-id: https://matroska.svn.sourceforge.net/svnroot/matroska/trunk/libmatroska@128 a6f86f6d-0131-4f8e-9e7b-e335508773d5

diff --git a/src/KaxBlock.cpp b/src/KaxBlock.cpp
index 4f794949cb5aa4201fbdc866c4f7e8ac09db615d..be00985e5dc2318400bb0a1850ea7ccb9263a4e6 100644 (file)
--- a/src/KaxBlock.cpp
+++ b/src/KaxBlock.cpp
@@ -283,8 +283,10 @@ filepos_t KaxBlockVirtual::UpdateSize(bool bSaveDefault, bool bForceRender)
        binary *cursor = EbmlBinary::GetBuffer();\r
        // fill data\r
        if (TrackNumber < 0x80) {\r
+        assert(GetSize() >= 4);\r
                *cursor++ = TrackNumber | 0x80; // set the first bit to 1 \r
        } else {\r
+        assert(GetSize() >= 5);\r
                *cursor++ = (TrackNumber >> 8) | 0x40; // set the second bit to 1\r
                *cursor++ = TrackNumber & 0xFF;\r
        }\r