1 files changed, 11 insertions, 0 deletions
diff --git a/dom/canvas/test/webgl-conf/checkout/conformance2/transform_feedback/simultaneous_binding.html b/dom/canvas/test/webgl-conf/checkout/conformance2/transform_feedback/simultaneous_binding.html
index 228b4ab5cf..11d1eaa829 100644
--- a/dom/canvas/test/webgl-conf/checkout/conformance2/transform_feedback/simultaneous_binding.html
+++ b/dom/canvas/test/webgl-conf/checkout/conformance2/transform_feedback/simultaneous_binding.html
@@ -304,6 +304,17 @@ for (let genericBindPointValue of genericBindPointValues) {
   gl.copyBufferSubData(gl.COPY_READ_BUFFER, gl.COPY_WRITE_BUFFER, 0, 0, 1);
   wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "copyBufferSubData with double bound buffer");
 
+  debug("<hr/>Test that rejected operations do not change the bound buffer size");
+
+  gl.bindBuffer(gl.ARRAY_BUFFER, tfBuffer);
+  gl.bufferData(gl.ARRAY_BUFFER, 8, gl.STATIC_DRAW);
+  wtu.glErrorShouldBe(gl, gl.INVALID_OPERATION, "bufferData with double bound buffer");
+
+  gl.bindTransformFeedback(gl.TRANSFORM_FEEDBACK, null);
+  gl.bufferSubData(gl.ARRAY_BUFFER, 0, new Uint8Array(16));
+  wtu.glErrorShouldBe(gl, gl.NO_ERROR, "bufferSubData should succeed");
+  gl.bindBuffer(gl.ARRAY_BUFFER, null);
+
   debug("<hr/>Test bufferData family with tf object unbound");
 
   gl.bindTransformFeedback(gl.TRANSFORM_FEEDBACK, null);