Fixed bug #33 Mike Frysinger wrote: > with libsdl-1.2.9, some games (like bomberclone) started > segfaulting in Gentoo [...snip...] > the last change in the last hunk: [...snip...] > if i change the statement to read: > (table[which].blit_features & GetBlitFeatures()) == GetBlitFeatures() > bomberclone no longer segfaults on my box Alex Volkov wrote: > The test "(table[which].blit_features & GetBlitFeatures()) == > table[which].blit_features)" is correct, and the previous > "(table[which].cpu_mmx == SDL_HasMMX())" was actually broken. I think there is potentially a slightly different cause of the above problem. During the introduction of the Altivec code, the blit_table struct field 'alpha' got changed from a straightforward enum to a bitmask, which makes perfect sense by itself. However, now the table driven blitter selection code in SDL_CalculateBlitN() can choose the wrong blitters when searching for a NO_ALPHA blitter because of the following code: int a_need = 0; ... (a_need & table[which].alpha) == a_need && When searching through the normal_blit_2[] table, a SET_ALPHA blitter (like Blit_RGB565_ARGB8888) can now be selected instead of a NO_ALPHA one, causing alpha channel bits to appear in a non-alpha destination surface. I suppose this could theoretically be an indirect cause of the segfault mentioned above. I *think* this can be fixed by changing to int a_need = NO_ALPHA;

These are test programs for the SDL library:

	testver		Check the version and dynamic loading and endianness
	testtypes	Check to see if the data types are the correct size
	testhread	Hacked up test of multi-threading
	testlock	Hacked up test of multi-threading and locking
	testerror	Tests multi-threaded error handling
	testsem		Tests SDL's semaphore implementation
	testtimer	Test the timer facilities
	loopwave	Audio test -- loop playing a WAV file
	testcdrom	Sample audio CD control program
	testkeys	List the available keyboard keys
	testvidinfo	Show the pixel format of the display and perfom the benchmark
	checkkeys	Watch the key events to check the keyboard
	testwin		Display a BMP image at various depths
	graywin		Display a gray gradient and center mouse on spacebar
	testsprite	Example of fast sprite movement on the screen
	testbitmap	Test displaying 1-bit bitmaps
	testalpha	Display an alpha faded icon -- paint with mouse
	testwm		Test window manager -- title, icon, events
	threadwin	Test multi-threaded event handling
	testgl		A very simple example of using OpenGL with SDL
	testjoystick	List joysticks and watch joystick events
	testoverlay	Tests the software/hardware overlay functionality.
	testoverlay2	Tests the overlay flickering/scaling during playback.
	testblitspeed	Tests performance of SDL's blitters and converters.