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Bug 3698

Summary: EGL and GL extension parsing has issues
Product: SDL Reporter: Simon Hug <chli.hug>
Component: videoAssignee: Sam Lantinga <slouken>
Status: RESOLVED FIXED QA Contact: Sam Lantinga <slouken>
Severity: normal    
Priority: P2    
Version: HG 2.0   
Hardware: All   
OS: All   
Attachments: Patch that fixes extension parsing issues and adds EGL client extension querying.

Description Simon Hug 2017-07-07 13:31:14 UTC 
Created attachment 2789 [details]
Patch that fixes extension parsing issues and adds EGL client extension querying.

SDL_EGL_HasExtension is unable to detect the last extension in the string if it is directly followed by the terminating zero.

SDL_GL_ExtensionSupported has an out-of-bounds guard when checking for the space character but uses the wrong pointer in the comparison. This may cause it to incorrectly report an extension as present. Example: GL_EXT_moo is matched in the second half of GL_EXT_mooGL_EXT_moo.

The attached patch fixes these issues and also adds querying of client extension with EGL_EXT_client_extensions and EGL 1.5. This will probably be used for the KMSDRM driver proposed in bug 3690.
Comment 1 Simon Hug 2017-07-07 13:33:51 UTC 
Oh, I forgot. In the patch, I commented out some error messages. Since the SDL_EGL_HasExtension function is an internal one, what would be the proper way to signal an error there? Asserts? Could you give me an example how that could look?
Comment 2 Simon Hug 2017-08-03 22:31:02 UTC 
This is now resolved. Fix was in the kmsdrm video driver patch.