Fix missing validation cache update on VAO binding.

src/libANGLE/Context.cpp

@@ -8705,6 +8705,7 @@ void StateCache::onVertexArrayBindingChange(Context *context)
     updateActiveAttribsMask(context);
     updateVertexElementLimits(context);
     updateBasicDrawStatesError();
+    updateBasicDrawElementsError();
 }
 
 void StateCache::onProgramExecutableChange(Context *context)

src/libANGLE/Context.h

@@ -204,6 +204,7 @@ class StateCache final : angle::NonCopyable
     // 2. onVertexArrayBufferStateChange.
     // 3. onBufferBindingChange.
     // 4. onVertexArrayStateChange.
+    // 5. onVertexArrayBindingStateChange.
     intptr_t getBasicDrawElementsError(const Context *context) const
     {
         if (mCachedBasicDrawElementsError != kInvalidPointer)

src/tests/gl_tests/StateChangeTest.cpp

@@ -5800,6 +5800,25 @@ TEST_P(RobustBufferAccessWebGL2ValidationStateChangeTest, BindZeroSizeBufferThen
     ASSERT_GL_NO_ERROR();
 }
 
+// Tests DrawElements with an empty buffer using a VAO.
+TEST_P(WebGL2ValidationStateChangeTest, DrawElementsEmptyVertexArray)
+{
+    ANGLE_GL_PROGRAM(program, essl1_shaders::vs::Simple(), essl1_shaders::fs::Red());
+
+    glUseProgram(program);
+
+    // Draw with empty buffer. Out of range but valid.
+    GLBuffer buffer;
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffer);
+    glDrawElements(GL_TRIANGLES, 0, GL_UNSIGNED_SHORT, reinterpret_cast<const GLvoid *>(0x1000));
+
+    // Switch VAO. No buffer bound, should be an error.
+    GLVertexArray vao;
+    glBindVertexArray(vao);
+    glDrawElements(GL_LINE_STRIP, 0x1000, GL_UNSIGNED_SHORT,
+                   reinterpret_cast<const GLvoid *>(0x1000));
+    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
+}
 }  // anonymous namespace
 
 ANGLE_INSTANTIATE_TEST_ES2(StateChangeTest);