commit 9494572a1798d5148d18d3db57c06ce07d608d23
author Nicolas Capens <capn@google.com> Fri Jun 30 17:07:33 2017 -0400
committer Nicolas Capens <capn@google.com> Tue Jul 04 18:07:19 2017 +0000
tree 911ad98cb6c52d4d1bab609db31430c515db3871
parent 9eaa19c2bcd788a4fc4fa6218dfa7f5544003a13

Fix allowing to make null EGL surfaces current.

eglMakeCurrent(display, EGL_NO_SURFACE, EGL_NO_SURFACE, context)
resulted in a null dereference. It should be supported and is a common
idiom for detaching the surfaces from the context before destroying
them.

Bug swiftshader:70

Change-Id: I5b4406c8d594bc5db34c51bd08371ce69bbd471b
Reviewed-on: https://swiftshader-review.googlesource.com/10389
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>

src/OpenGL/libGLESv2/Context.cpp

diff --git a/src/OpenGL/libGLESv2/Context.cpp b/src/OpenGL/libGLESv2/Context.cpp
index 5e99607..84196ac 100644
--- a/src/OpenGL/libGLESv2/Context.cpp
+++ b/src/OpenGL/libGLESv2/Context.cpp
@@ -274,35 +274,42 @@
 
 		mState.viewportX = 0;
 		mState.viewportY = 0;
-		mState.viewportWidth = surface->getWidth();
-		mState.viewportHeight = surface->getHeight();
+		mState.viewportWidth = surface ? surface->getWidth() : 0;
+		mState.viewportHeight = surface ? surface->getHeight() : 0;
 
 		mState.scissorX = 0;
 		mState.scissorY = 0;
-		mState.scissorWidth = surface->getWidth();
-		mState.scissorHeight = surface->getHeight();
+		mState.scissorWidth = surface ? surface->getWidth() : 0;
+		mState.scissorHeight = surface ? surface->getHeight() : 0;
 
 		mHasBeenCurrent = true;
 	}
 
-	// Wrap the existing resources into GL objects and assign them to the '0' names
-	egl::Image *defaultRenderTarget = surface->getRenderTarget();
-	egl::Image *depthStencil = surface->getDepthStencil();
-
-	Colorbuffer *colorbufferZero = new Colorbuffer(defaultRenderTarget);
-	DepthStencilbuffer *depthStencilbufferZero = new DepthStencilbuffer(depthStencil);
-	Framebuffer *framebufferZero = new DefaultFramebuffer(colorbufferZero, depthStencilbufferZero);
-
-	setFramebufferZero(framebufferZero);
-
-	if(defaultRenderTarget)
+	if(surface)
 	{
-		defaultRenderTarget->release();
+		// Wrap the existing resources into GL objects and assign them to the '0' names
+		egl::Image *defaultRenderTarget = surface->getRenderTarget();
+		egl::Image *depthStencil = surface->getDepthStencil();
+
+		Colorbuffer *colorbufferZero = new Colorbuffer(defaultRenderTarget);
+		DepthStencilbuffer *depthStencilbufferZero = new DepthStencilbuffer(depthStencil);
+		Framebuffer *framebufferZero = new DefaultFramebuffer(colorbufferZero, depthStencilbufferZero);
+
+		setFramebufferZero(framebufferZero);
+
+		if(defaultRenderTarget)
+		{
+			defaultRenderTarget->release();
+		}
+
+		if(depthStencil)
+		{
+			depthStencil->release();
+		}
 	}
-
-	if(depthStencil)
+	else
 	{
-		depthStencil->release();
+		setFramebufferZero(nullptr);
 	}
 
 	markAllStateDirty();