Fixed bug #526 Comment #1 From Simon Howard 2009-03-20 16:50:56 Hi, I'm the author of Chocolate Doom, one of the other source ports that James mentioned. This is a patch against the current SVN version of SDL 1.2 that fixes the bug. It has been tested and hopefully should be obviously correct from examining the changes. I'll give a brief explanation. When the palette is set with SDL_SetPalette, the IDirectDrawPalette_SetEntries DirectX function is invoked. However, when this happens, a WM_PALETTECHANGED message is sent to the window. A WM_PALETTECHANGED message can also be received if the palette is changed for some other reason, like if the system palette is changed. Therefore, the palette change handler (DX5_PaletteChanged) has code to deal with this case. It distinguishes "expected" palette changes (set with SDL_SetPalette) from "unexpected" palette changes using the colorchange_expected variable, which is set before calling IDirectDrawPalette_SetEntries. However, the code to set this variable is missing in the fullscreen code path. By setting this variable, the palette change is handled properly and the freezes go away.

--- a/src/video/windx5/SDL_dx5video.c	Thu Apr 02 04:43:36 2009 +0000
+++ b/src/video/windx5/SDL_dx5video.c	Mon Apr 13 00:53:12 2009 +0000
@@ -2266,6 +2266,8 @@
 				SDL_colors[j].peGreen = colors[i].g;
 				SDL_colors[j].peBlue = colors[i].b;
 			}
+			/* This sends an WM_PALETTECHANGED message to us */
+			colorchange_expected = 1;
 			IDirectDrawPalette_SetEntries(SDL_palette, 0,
 				firstcolor, ncolors, &SDL_colors[firstcolor]);
 			alloct_all = 1;