Bug 717442 - Shadow bound FBO ids - r=bjacob

gfx/gl/GLContext.h

@@ -533,6 +533,8 @@ public:
               bool aIsOffscreen = false,
               GLContext *aSharedContext = nsnull)
       : mFlushGuaranteesResolve(false),
+        mBoundDrawFBO(0),
+        mBoundReadFBO(0),
         mOffscreenFBOsDirty(false),
         mInitialized(false),
         mIsOffscreen(aIsOffscreen),
@@ -775,11 +777,10 @@ public:
         return mIsOffscreen;
     }
 
-protected:
+private:
     bool mFlushGuaranteesResolve;
 
 public:
-
     void SetFlushGuaranteesResolve(bool aFlushGuaranteesResolve) {
         mFlushGuaranteesResolve = aFlushGuaranteesResolve;
     }
@@ -851,22 +852,59 @@ public:
         return IsExtensionSupported(EXT_framebuffer_blit) || IsExtensionSupported(ANGLE_framebuffer_blit);
     }
 
+
+
+private:
+    GLuint mBoundDrawFBO;
+    GLuint mBoundReadFBO;
+
+public:
+    void fBindFramebuffer(GLenum target, GLuint framebuffer) {
+        switch (target) {
+          case LOCAL_GL_FRAMEBUFFER:
+            mBoundDrawFBO = mBoundReadFBO = framebuffer;
+            break;
+          case LOCAL_GL_DRAW_FRAMEBUFFER_EXT:
+            mBoundDrawFBO = framebuffer;
+            break;
+          case LOCAL_GL_READ_FRAMEBUFFER_EXT:
+            mBoundReadFBO = framebuffer;
+            break;
+        }
+        raw_fBindFramebuffer(target, framebuffer);
+    }
+
     GLuint GetBoundDrawFBO() {
+#ifdef DEBUG
         GLint ret = 0;
-        if (SupportsOffscreenSplit())
-            fGetIntegerv(LOCAL_GL_DRAW_FRAMEBUFFER_BINDING_EXT, &ret);
-        else
-            fGetIntegerv(LOCAL_GL_FRAMEBUFFER_BINDING, &ret);
-        return ret;
+        // Don't need a branch here, because:
+        // LOCAL_GL_DRAW_FRAMEBUFFER_BINDING_EXT == LOCAL_GL_FRAMEBUFFER_BINDING == 0x8CA6
+        fGetIntegerv(LOCAL_GL_DRAW_FRAMEBUFFER_BINDING_EXT, &ret);
+
+        if (mBoundDrawFBO != (GLuint)ret) {
+          printf_stderr("!!! Draw FBO mismatch: Was: %d, Expected: %d\n", ret, mBoundDrawFBO);
+          NS_ABORT();
+        }
+#endif
+
+        return mBoundDrawFBO;
     }
 
     GLuint GetBoundReadFBO() {
+#ifdef DEBUG
         GLint ret = 0;
         if (SupportsOffscreenSplit())
             fGetIntegerv(LOCAL_GL_READ_FRAMEBUFFER_BINDING_EXT, &ret);
         else
             fGetIntegerv(LOCAL_GL_FRAMEBUFFER_BINDING, &ret);
-        return ret;
+
+        if (mBoundReadFBO != (GLuint)ret) {
+          printf_stderr("!!! Read FBO mismatch: Was: %d, Expected: %d\n", ret, mBoundReadFBO);
+          NS_ABORT();
+        }
+#endif
+
+        return mBoundReadFBO;
     }
 
     void BindDrawFBO(GLuint name) {
@@ -2421,12 +2459,14 @@ public:
         AFTER_GL_CALL;
     }
 
-    void fBindFramebuffer(GLenum target, GLuint framebuffer) {
+private:
+    void raw_fBindFramebuffer(GLenum target, GLuint framebuffer) {
         BEFORE_GL_CALL;
         mSymbols.fBindFramebuffer(target, framebuffer);
         AFTER_GL_CALL;
     }
 
+public:
     void fBindRenderbuffer(GLenum target, GLuint renderbuffer) {
         BEFORE_GL_CALL;
         mSymbols.fBindRenderbuffer(target, renderbuffer);