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>

diff --git a/src/OpenGL/libGLESv2/Context.cpp b/src/OpenGL/libGLESv2/Context.cpp
index 5e99607..84196ac 100644 (file)
--- a/src/OpenGL/libGLESv2/Context.cpp
+++ b/src/OpenGL/libGLESv2/Context.cpp
@@ -274,35 +274,42 @@ void Context::makeCurrent(gl::Surface *surface)
 
                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();
+       if(surface)
+       {
+               // 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);
+               Colorbuffer *colorbufferZero = new Colorbuffer(defaultRenderTarget);
+               DepthStencilbuffer *depthStencilbufferZero = new DepthStencilbuffer(depthStencil);
+               Framebuffer *framebufferZero = new DefaultFramebuffer(colorbufferZero, depthStencilbufferZero);
 
-       setFramebufferZero(framebufferZero);
+               setFramebufferZero(framebufferZero);
 
-       if(defaultRenderTarget)
-       {
-               defaultRenderTarget->release();
-       }
+               if(defaultRenderTarget)
+               {
+                       defaultRenderTarget->release();
+               }
 
-       if(depthStencil)
+               if(depthStencil)
+               {
+                       depthStencil->release();
+               }
+       }
+       else
        {
-               depthStencil->release();
+               setFramebufferZero(nullptr);
        }
 
        markAllStateDirty();