Bug 1263018 - Only update active prog info if linking active prog. - r=jrmuizel

dom/canvas/WebGLContextDraw.cpp

@@ -360,8 +360,10 @@ WebGLContext::DrawElements_check(GLsizei count, GLenum type,
         return false;
     }
 
-    // Any checks below this depend on a program being available.
-    if (!mCurrentProgram) {
+    // Any checks below this depend on mActiveProgramLinkInfo being available.
+    if (!mActiveProgramLinkInfo) {
+        // Technically, this will only be null iff CURRENT_PROGRAM is null.
+        // But it's better to branch on what we actually care about.
         ErrorInvalidOperation("%s: null CURRENT_PROGRAM", info);
         return false;
     }

dom/canvas/WebGLContextGL.cpp

@@ -1088,14 +1088,19 @@ WebGLContext::LinkProgram(WebGLProgram* prog)
 
     prog->LinkProgram();
 
-    if (prog->IsLinked()) {
+    if (!prog->IsLinked()) {
+        // If we failed to link, but `prog == mCurrentProgram`, we are *not* supposed to
+        // null out mActiveProgramLinkInfo.
+        return;
+    }
+
+    if (prog == mCurrentProgram) {
         mActiveProgramLinkInfo = prog->LinkInfo();
 
         if (gl->WorkAroundDriverBugs() &&
             gl->Vendor() == gl::GLVendor::NVIDIA)
         {
-            if (mCurrentProgram == prog)
-                gl->fUseProgram(prog->mGLName);
+            gl->fUseProgram(prog->mGLName);
         }
     }
 }

dom/canvas/WebGLProgram.cpp

@@ -885,7 +885,7 @@ WebGLProgram::UniformBlockBinding(GLuint uniformBlockIndex, GLuint uniformBlockB
     gl->fUniformBlockBinding(mGLName, uniformBlockIndex, uniformBlockBinding);
 }
 
-bool
+void
 WebGLProgram::LinkProgram()
 {
     mContext->InvalidateBufferFetching(); // we do it early in this function
@@ -897,18 +897,18 @@ WebGLProgram::LinkProgram()
     if (!mVertShader || !mVertShader->IsCompiled()) {
         mLinkLog.AssignLiteral("Must have a compiled vertex shader attached.");
         mContext->GenerateWarning("linkProgram: %s", mLinkLog.BeginReading());
-        return false;
+        return;
     }
 
     if (!mFragShader || !mFragShader->IsCompiled()) {
         mLinkLog.AssignLiteral("Must have an compiled fragment shader attached.");
         mContext->GenerateWarning("linkProgram: %s", mLinkLog.BeginReading());
-        return false;
+        return;
     }
 
     if (!mFragShader->CanLinkTo(mVertShader, &mLinkLog)) {
         mContext->GenerateWarning("linkProgram: %s", mLinkLog.BeginReading());
-        return false;
+        return;
     }
 
     gl::GLContext* gl = mContext->gl;
@@ -925,14 +925,14 @@ WebGLProgram::LinkProgram()
             mLinkLog.AssignLiteral("Programs with more than 16 samplers are disallowed on"
                                    " Mesa drivers to avoid crashing.");
             mContext->GenerateWarning("linkProgram: %s", mLinkLog.BeginReading());
-            return false;
+            return;
         }
 
         // Bug 1203135: Mesa crashes internally if we exceed the reported maximum attribute count.
         if (mVertShader->NumAttributes() > mContext->MaxVertexAttribs()) {
             mLinkLog.AssignLiteral("Number of attributes exceeds Mesa's reported max attribute count.");
             mContext->GenerateWarning("linkProgram: %s", mLinkLog.BeginReading());
-            return false;
+            return;
         }
     }
 
@@ -954,8 +954,9 @@ WebGLProgram::LinkProgram()
                                                     &mTempMappedVaryings);
     }
 
-    if (LinkAndUpdate())
-        return true;
+    LinkAndUpdate();
+    if (IsLinked())
+        return;
 
     // Failed link.
     if (mContext->ShouldGenerateWarnings()) {
@@ -970,8 +971,6 @@ WebGLProgram::LinkProgram()
                                       mLinkLog.BeginReading());
         }
     }
-
-    return false;
 }
 
 bool
@@ -1013,7 +1012,7 @@ WebGLProgram::ValidateProgram() const
 
 ////////////////////////////////////////////////////////////////////////////////
 
-bool
+void
 WebGLProgram::LinkAndUpdate()
 {
     mMostRecentLinkInfo = nullptr;
@@ -1039,15 +1038,10 @@ WebGLProgram::LinkAndUpdate()
     GLint ok = 0;
     gl->fGetProgramiv(mGLName, LOCAL_GL_LINK_STATUS, &ok);
     if (!ok)
-        return false;
+        return;
 
     mMostRecentLinkInfo = QueryProgramInfo(this, gl);
-
-    MOZ_ASSERT(mMostRecentLinkInfo);
-    if (!mMostRecentLinkInfo)
-        mLinkLog.AssignLiteral("Failed to gather program info.");
-
-    return mMostRecentLinkInfo;
+    MOZ_RELEASE_ASSERT(mMostRecentLinkInfo);
 }
 
 bool

dom/canvas/WebGLProgram.h

@@ -156,7 +156,7 @@ public:
                            dom::Nullable< nsTArray<GLuint> >& retval) const;
     void UniformBlockBinding(GLuint uniformBlockIndex, GLuint uniformBlockBinding) const;
 
-    bool LinkProgram();
+    void LinkProgram();
     bool UseProgram() const;
     void ValidateProgram() const;
 
@@ -195,7 +195,7 @@ public:
 private:
     ~WebGLProgram();
 
-    bool LinkAndUpdate();
+    void LinkAndUpdate();
 
 public:
     const GLuint mGLName;