Fix that 0 is a valid memory barrier

src/libANGLE/validationES31.cpp

@@ -1744,7 +1744,7 @@ bool ValidateMemoryBarrier(Context *context, GLbitfield barriers)
         GL_PIXEL_BUFFER_BARRIER_BIT | GL_TEXTURE_UPDATE_BARRIER_BIT | GL_BUFFER_UPDATE_BARRIER_BIT |
         GL_FRAMEBUFFER_BARRIER_BIT | GL_TRANSFORM_FEEDBACK_BARRIER_BIT |
         GL_ATOMIC_COUNTER_BARRIER_BIT | GL_SHADER_STORAGE_BARRIER_BIT;
-    if ((barriers & ~supported_barrier_bits) != 0)
+    if (barriers == 0 || (barriers & ~supported_barrier_bits) != 0)
     {
         context->validationError(GL_INVALID_VALUE, kInvalidMemoryBarrierBit);
         return false;
@@ -1770,7 +1770,7 @@ bool ValidateMemoryBarrierByRegion(Context *context, GLbitfield barriers)
                                         GL_SHADER_IMAGE_ACCESS_BARRIER_BIT |
                                         GL_SHADER_STORAGE_BARRIER_BIT |
                                         GL_TEXTURE_FETCH_BARRIER_BIT | GL_UNIFORM_BARRIER_BIT;
-    if ((barriers & ~supported_barrier_bits) != 0)
+    if (barriers == 0 || (barriers & ~supported_barrier_bits) != 0)
     {
         context->validationError(GL_INVALID_VALUE, kInvalidMemoryBarrierBit);
         return false;

src/tests/gl_tests/ComputeShaderTest.cpp

@@ -2749,6 +2749,14 @@ void main()
     EXPECT_EQ(expectedValue, outputValues);
 }
 
+// Test that invalid memory barrier will produce an error.
+TEST_P(ComputeShaderTest, InvalidMemoryBarrier)
+{
+    GLbitfield barriers = 0;
+    glMemoryBarrier(barriers);
+    EXPECT_GL_ERROR(GL_INVALID_VALUE);
+}
+
 ANGLE_INSTANTIATE_TEST(ComputeShaderTest, ES31_OPENGL(), ES31_OPENGLES(), ES31_D3D11());
 ANGLE_INSTANTIATE_TEST(ComputeShaderTestES3, ES3_OPENGL(), ES3_OPENGLES());
 ANGLE_INSTANTIATE_TEST(WebGL2ComputeTest, ES31_D3D11());