Bug 6909

Summary:	cairo_surface_write_to_png_stream ignores status returned by the write function
Product:	cairo	Reporter:	Torsten Schönfeld <kaffeetisch>
Component:	png functions	Assignee:	Carl Worth <cworth>
Status:	RESOLVED FIXED	QA Contact:	cairo-bugs mailing list <cairo-bugs>
Severity:	normal
Priority:	high
Version:	1.1.7
Hardware:	x86 (IA32)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:

Description Torsten Schönfeld 2006-05-14 03:47:09 UTC

In case of an error (status != CAIRO_STATUS_SUCCESS)
cairo_surface_write_to_png_stream seems to ignore what the write function
actually returned.  It always simply returns CAIRO_STATUS_NO_MEMORY (that's what
that setjmp branch sets).

A quick look at the source reveals that this probably isn't easy to change since
png_rw_ptr doesn't have a return value, but I thought I file it anyway in case I
missed something obvious.  Feel free to dismiss this bug report if there is
nothing that can be done about it.

Comment 1 Chris Wilson 2007-09-25 15:49:20 UTC

I found a png_error_ptr through which we can propagate the error status.

Pushed:
commit 1469de5211e84e40490fa612538986768748bd55
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Sep 25 23:35:25 2007 +0100

    [cairo-png] Propagate error from read and write funcs.
    
    Use the png_struct->error_ptr to propagate the error status from the
    user/stdio read and write functions through the png_error() to the
    cairo_surface_write_to_png*() and cairo_surface_read_from_png*()
    functions. From there the error is returned back to the user either
    directly or as the most appropriate error surface.
    
    (Fixes https://bugs.freedesktop.org/show_bug.cgi?id=6909)

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