Bug 696495 - texture-mips.html failures might be workaroundable by setting minification filter before glGenerateMipmap call - r=jgilbert

content/canvas/src/WebGLContextGL.cpp

@@ -1903,7 +1903,15 @@ WebGLContext::GenerateMipmap(WebGLenum target)
     tex->SetGeneratedMipmap();
 
     MakeContextCurrent();
+    
+    // bug 696495 - to work around failures in the texture-mips.html test, at least on WinXP and Mac, we
+    // set the minification filter before calling glGenerateMipmap. This should not carry a significant performance
+    // overhead so we do it unconditionally.
+    //
+    // note that the choice of GL_NEAREST_MIPMAP_NEAREST really matters. See Chromium bug 101105.
+    gl->fTexParameteri(target, LOCAL_GL_TEXTURE_MIN_FILTER, LOCAL_GL_NEAREST_MIPMAP_NEAREST);
     gl->fGenerateMipmap(target);
+    gl->fTexParameteri(target, LOCAL_GL_TEXTURE_MIN_FILTER, tex->MinFilter());
     return NS_OK;
 }
 

content/canvas/test/webgl/failing_tests_linux.txt

@@ -4,7 +4,6 @@ conformance/glsl/misc/shader-with-256-character-identifier.frag.html
 conformance/glsl/misc/shader-with-long-line.html
 conformance/misc/uninitialized-test.html
 conformance/programs/gl-get-active-attribute.html
-conformance/textures/texture-mips.html
 conformance/uniforms/gl-uniform-bool.html
 conformance/more/conformance/quickCheckAPI-S_V.html
 conformance/more/functions/uniformfArrayLen1.html