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| author | Alex Rostovtsev <tetromino@gmail.com> | 2008-08-19 23:45:40 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2008-08-19 23:45:40 +0100 |
| commit | 186e7a2602cf140ac03b730b95ed10f25f9319c6 (patch) | |
| tree | fc70f7ddf8180c5ce3c948750643e9984ed64d8f /src/cairo-png.c | |
| parent | 5712a2c619b265a7ede5cd32049bce456131c64b (diff) | |
| download | cairo-186e7a2602cf140ac03b730b95ed10f25f9319c6.tar.gz | |
[png] Specify a no-op flush callback (NULL deref)
libpng changed behaviour in v1.2.30 to call the png_ptr->output_flush_fn
in png_write_end(). If no flush function is provided with
png_set_write_fn(), libpng will use its default fflush() instead - which
assumes that closure passed is a FILE* and not an arbitrary user pointer.
Consequently, we must actually set a dummy output_flush_fn to avoid
segfaulting.
Diffstat (limited to 'src/cairo-png.c')
| -rw-r--r-- | src/cairo-png.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/src/cairo-png.c b/src/cairo-png.c index ae3a1f7b6..1b7df9abe 100644 --- a/src/cairo-png.c +++ b/src/cairo-png.c @@ -119,6 +119,13 @@ png_simple_warning_callback (png_structp png, } +/* Starting with libpng-1.2.30, we must explicitly specify an output_flush_fn. + * Otherwise, we will segfault if we are writing to a stream. */ +static void +png_simple_output_flush_fn (png_structp png_ptr) +{ +} + static cairo_status_t write_png (cairo_surface_t *surface, png_rw_ptr write_func, @@ -179,7 +186,7 @@ write_png (cairo_surface_t *surface, goto BAIL3; #endif - png_set_write_fn (png, closure, write_func, NULL); + png_set_write_fn (png, closure, write_func, png_simple_output_flush_fn); switch (image->format) { case CAIRO_FORMAT_ARGB32: |