I wasn't able to reproduce this by modifying test/testrendercopyex.c to set the width and height to zero in the SDL_RenderCopyEx() call.

What renderer are you using, and can you attach a quick test to show the crash?

Thanks!

That was quick Sam, hi :)

Only happens in the software renderer.

SDL_CreateRenderer(window, 3, 0); // 3 = software renderer on my system

If that doesn't trigger it, I will dig deeper and put a test together.

Yeah, that didn't trigger it for me. Are you using the latest SDL snapshot?
http://www.libsdl.org/tmp/SDL-2.0.zip

I remember that something like this was fixed a while back.

(In reply to Sam Lantinga from comment #3)
> Yeah, that didn't trigger it for me. Are you using the latest SDL snapshot?
> http://www.libsdl.org/tmp/SDL-2.0.zip
> 
> I remember that something like this was fixed a while back.

I'm using the 2.0.5 .lib files.

I see there have been fixes to the software SDL_RenderCopyEx recently this month, which has probably fixed it.

I had problems linking the snapshots before, but I will try again and see if that solves it. Thanks Sam. Please bare with...

I have tried to reproduce the case also, with latest source, 2.0.4 and 2.0.5 and I have seen nothing. So is there a real issue with this ?

Can you confirm you were using the software renderer and drawing a rotated texture?

Set either the w or h of the destination rectangle to 0, and rotation to a value higher than 0.

I've tested again and it's still crashing. I dropped the 2.0.6 DLL in, and it still crashes.

Yes angle = 30, sprite->w = 3, renderer = software.

maybe, make sure you are using the software renderer :

SDL_RendererInfo info;
SDL_GetRendererInfo(renderer, &info);
SDL_Log("Renderer %s", info.name);

I tried also with testrendercopyex.c

Created attachment 2953 [details]
screen shot of comprehensive graphics options in PowBall Renaissance

You mean sprite->w = 0? The crash only happens when width or height is zero.

I have comprehensive graphics settings in the game I made which lets you cycle through all the avaliable renderers. This only happens in the software renderer. opengl, opengles, direct3D all work fine.

Sorry, I mean't "s->sprite_rect.w = 0;" of testrendercopyex.c

this is intriguing. you should definitively build a testcase.

I think this is fixed in the 2.0.6 pre-release:
http://www.libsdl.org/tmp/download-2.0.php

yep, but Anthony says it still happens with 2.0.6 DLL.
And It won't get reproduced with an older SDL2. 

Maybe a bug that testrendercopyex is not covering.

I've been digging deeper into this problem. I think it's something to do with the format of my SDL_Texture. It could be the pixel format or dimensions of the texture. If I create an empty texture and use that in place of the texture I've created from loading a PNG (with LodePNG), it doesn't crash. I'll continue to dig deeper.

I've never been able to compile SDL from source; I don't know how to set it up, so I can't step through where CopyEx crashes.

This is what's making the software renderer crash with rotated destination rectangles of w or h = 0:

SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "2");

Great. Can you attach a minimal example that we can use to reproduce this?

Thanks!

Great, this can be reproduced now. This happens when renderCopyEx take the "smooth" path. it's a regression from bug 1550 (https://hg.libsdl.org/SDL/rev/5c4a85c5b648)

and putting back the correct condition fix it:


diff -r 8ab64b5850ae src/render/software/SDL_rotate.c
--- a/src/render/software/SDL_rotate.c	Fri Sep 15 17:27:32 2017 -0700
+++ b/src/render/software/SDL_rotate.c	Thu Sep 21 10:06:16 2017 +0200
@@ -257,7 +257,7 @@
                 dy = (sdy >> 16);
                 if (flipx) dx = sw - dx;
                 if (flipy) dy = sh - dy;
-                if ((unsigned)dx < (unsigned)sw && (unsigned)dy < (unsigned)sh) {
+                if ((dx > -1) && (dy > -1) && (dx < (src->w-1)) && (dy < (src->h-1))) {
                     sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy) + dx;
                     c00 = *sp;
                     sp += 1;

Fixed, thanks!
https://hg.libsdl.org/SDL/rev/833d4fbb3d76