[Mono-bugs] [Bug 76844][Nor] Changed - Unlockbits fails

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Changed by 4lw0e0402 at sneakemail.com.

http://bugzilla.ximian.com/show_bug.cgi?id=76844

--- shadow/76844	2005-11-29 17:37:27.000000000 -0500
+++ shadow/76844.tmp.3661	2005-12-01 23:24:57.000000000 -0500
@@ -1,13 +1,13 @@
 Bug#: 76844
 Product: Mono: Class Libraries
 Version: unspecified
 OS: unknown
 OS Details: 
-Status: NEW   
-Resolution: 
+Status: RESOLVED   
+Resolution: FIXED
 Severity: Unknown
 Priority: Normal
 Component: Windows.Forms
 AssignedTo: peter at novonyx.com                            
 ReportedBy: miguel at ximian.com               
 QAContact: mono-bugs at ximian.com
@@ -113,6 +113,27 @@
 
 
 ------- Additional Comments From peter at novonyx.com  2005-11-29 17:37 -------
 Am CCing Jonathan Gilbert on this bug, he worked on (Un)LockBits as 
 part of his adding support for indexed images patch, he may have some 
 insight.
+
+------- Additional Comments From 4lw0e0402 at sneakemail.com  2005-12-01 23:24 -------
+Both of the examples are broken because they assume the data will be 
+tightly-packed instead of using BitmapData's Stride member, but this 
+was not evident because there is indeed a bug in UnlockBits :-)
+
+The bug was basically a typo:
+
+if ((locked_data->Reserved & GBD_READ_ONLY) != 0) {
+
+...should have been:
+
+if ((locked_data->Reserved & GBD_READ_ONLY) == 0) {
+
+However, this was in fact hiding a couple of deeper problems to do 
+with 24-bit <-> 32-bit conversions. These required fixing, mostly in 
+the pixel stream code.
+
+I have fixed all of these problems and will shortly attach a patch to 
+this bug for review. If it passes, I can commit the changes directly. 
+I will also add a regression test for this issue.