Bug 6301

Summary:	Empty image if destination region is bigger than source bitmap
Product:	cairo	Reporter:	Alexander Darovsky <adarovsky>
Component:	win32 backend	Assignee:	Owen Taylor <otaylor>
Status:	RESOLVED FIXED	QA Contact:	cairo-bugs mailing list <cairo-bugs>
Severity:	normal
Priority:	high	CC:	chris
Version:	1.0.2
Hardware:	Other
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	fix

Description Alexander Darovsky 2006-03-17 21:55:32 UTC

Here is a little bug in win32 backend, which, however, causes  
AlphaBlend to fail with "invalid argument" error code.   
  
The problem arises when src_x or src_y < 0, or when width or height is 
bigger than source bitmap. Applied patch solves this problem, and also 
fixes LoadLibrary issue. We must call LoadLibraryA or enclose "msimg32" 
into special macro.

Comment 1 Alexander Darovsky 2006-03-17 21:56:58 UTC

Created attachment 4980 [details] [review]
fix

This patch fixes problems with msimg32 loading and AlphaBlend call

Comment 2 Chris Wilson 2008-01-11 09:07:55 UTC

Adrian Johnson fixed the LoadLibraryA issue with commit f20a1a40c3f6d95b4dc89ae4198ad81b7092450c.

However, it should be impossible for AlphaBlend() to be called with a src rectangle that lies outside the source as it is fixed up by the caller (_cairo_win32_surface_composite, lines 1042-66 and added in commit 68ed40b6da242816a43cd68cc2c7feb779cf0acf by Vladimir Vukicevic).

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