* bug#8238: possibly uninitialized variable in gif_load
@ 2011-03-13 7:17 Paul Eggert
2011-03-13 10:27 ` Julien Danjou
0 siblings, 1 reply; 3+ messages in thread
From: Paul Eggert @ 2011-03-13 7:17 UTC (permalink / raw)
To: 8238; +Cc: Julien Danjou
I found this problem by code inspection.
The following code in the Emacs trunk src/image.c's gif_load
function is suspicious, because it uses a variable transparent_p
that appears to be uninitialized in some cases:
boolean transparent_p;
...
for (i = 0; i < gif->SavedImages[ino].ExtensionBlockCount; i++)
if ((gif->SavedImages[ino].ExtensionBlocks[i].Function
== GIF_LOCAL_DESCRIPTOR_EXTENSION)
&& gif->SavedImages[ino].ExtensionBlocks[i].ByteCount == 4
/* Transparency enabled? */
&& gif->SavedImages[ino].ExtensionBlocks[i].Bytes[0] & 1)
{
transparent_p = 1;
...
}
...
if (gif_color_map)
for (i = 0; i < gif_color_map->ColorCount; ++i)
{
if (transparent_p && transparency_color_index == i)
The code never sets transparent_p to any value other than 1,
but sometimes transparent_p appears to be uninitialized.
I'm filing a bug report so that someone who is more expert in this
code can take a look at it. In the meantime, I plan to work around
the problem by initializing the variable to 0.
I'm CC'ing this to Julien Danjou, who committed the code in question.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2011-03-13 17:43 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-03-13 7:17 bug#8238: possibly uninitialized variable in gif_load Paul Eggert
2011-03-13 10:27 ` Julien Danjou
2011-03-13 17:43 ` Paul Eggert
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).