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| author | Robert Ancell <robert.ancell@canonical.com> | 2018-12-12 12:46:44 +1300 |
|---|---|---|
| committer | Robert Ancell <robert.ancell@canonical.com> | 2019-01-16 15:47:09 +1300 |
| commit | 88ceed9ed1e823ffd797df798d429d15bc7efd39 (patch) | |
| tree | df02ce09e148825988eeb175528925148baefb25 | |
| parent | b9b12bfd5c6f8394cc9a4a548bd6dc0f5fb2f70b (diff) | |
| download | gdk-pixbuf-88ceed9ed1e823ffd797df798d429d15bc7efd39.tar.gz | |
gif: Fix clear code handling when at end of a block
The following was occurring:
1. A clear code is detected in the LZW stream.
2. The decoder enters a clear code handling state.
3. The decoder looks for the next code after the clear.
4. The decoder has run out of blocks, so enters a state to get new blocks
The issue is in step 4 the decoder has assumed the clear state is complete,
when it is not. The solution is to only complete the clear state once a
non clear code is read.
This caused the "Circular table entry in GIF file" error for some GIFs.
Fixes https://gitlab.gnome.org/GNOME/gdk-pixbuf/issues/27
Fixes https://gitlab.gnome.org/GNOME/gdk-pixbuf/issues/69
| -rw-r--r-- | gdk-pixbuf/io-gif.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/gdk-pixbuf/io-gif.c b/gdk-pixbuf/io-gif.c index 244d8788f..f2207360e 100644 --- a/gdk-pixbuf/io-gif.c +++ b/gdk-pixbuf/io-gif.c @@ -572,7 +572,6 @@ lzw_read_byte (GifContext *context) register int i; if (context->lzw_fresh) { - context->lzw_fresh = FALSE; do { retval = get_code (context, context->lzw_code_size); if (retval < 0) { @@ -581,6 +580,7 @@ lzw_read_byte (GifContext *context) context->lzw_firstcode = context->lzw_oldcode = retval; } while (context->lzw_firstcode == context->lzw_clear_code); + context->lzw_fresh = FALSE; return context->lzw_firstcode; } |