WebGL Compat: forbid client side arrays, even unused

src/libANGLE/validationES.cpp

@@ -51,15 +51,17 @@ bool ValidateDrawAttribs(ValidationContext *context,
     for (size_t attributeIndex = 0; attributeIndex < maxEnabledAttrib; ++attributeIndex)
     {
         const VertexAttribute &attrib = vertexAttribs[attributeIndex];
-        if (!program->isAttribLocationActive(attributeIndex) || !attrib.enabled)
+
+        // No need to range check for disabled attribs.
+        if (!attrib.enabled)
         {
             continue;
         }
 
-        const VertexBinding &binding = vertexBindings[attrib.bindingIndex];
         // If we have no buffer, then we either get an error, or there are no more checks to be
         // done.
-        gl::Buffer *buffer = binding.getBuffer().get();
+        const VertexBinding &binding  = vertexBindings[attrib.bindingIndex];
+        gl::Buffer *buffer            = binding.getBuffer().get();
         if (!buffer)
         {
             if (webglCompatibility || !state.areClientArraysEnabled())
@@ -84,6 +86,13 @@ bool ValidateDrawAttribs(ValidationContext *context,
             continue;
         }
 
+        // This needs to come after the check for client arrays as even unused attributes cannot use
+        // client-side arrays
+        if (!program->isAttribLocationActive(attributeIndex))
+        {
+            continue;
+        }
+
         // If we're drawing zero vertices, we have enough data.
         if (vertexCount <= 0 || primcount <= 0)
         {

src/tests/gl_tests/WebGLCompatibilityTest.cpp

@@ -573,6 +573,35 @@ TEST_P(WebGLCompatibilityTest, ForbidsClientSideElementBuffer)
     EXPECT_GL_ERROR(GL_INVALID_OPERATION);
 }
 
+// Test that client-side array buffers are forbidden even if the program doesn't use the attribute
+TEST_P(WebGLCompatibilityTest, ForbidsClientSideArrayBufferEvenNotUsedOnes)
+{
+    const std::string &vert =
+        "void main()\n"
+        "{\n"
+        "    gl_Position = vec4(1.0);\n"
+        "}\n";
+
+    const std::string &frag =
+        "precision highp float;\n"
+        "void main()\n"
+        "{\n"
+        "    gl_FragColor = vec4(1.0);\n"
+        "}\n";
+
+    ANGLE_GL_PROGRAM(program, vert, frag);
+
+    glUseProgram(program.get());
+
+    const auto &vertices = GetQuadVertices();
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 4, vertices.data());
+    glEnableVertexAttribArray(0);
+
+    ASSERT_GL_NO_ERROR();
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
+}
+
 // Tests the WebGL requirement of having the same stencil mask, writemask and ref for fron and back
 TEST_P(WebGLCompatibilityTest, RequiresSameStencilMaskAndRef)
 {