Add error check on resuming XFB with deleted buffer.

Bug: chromium:1305190
Change-Id: I22c6f6400b05ca32c922fba9a3b9d4b5841ca8b8
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3578378
Auto-Submit: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

src/libANGLE/validationES3.cpp

@@ -4377,6 +4377,13 @@ bool ValidateResumeTransformFeedback(const Context *context, angle::EntryPoint e
         return false;
     }
 
+    if (!ValidateProgramExecutableXFBBuffersPresent(context,
+                                                    context->getState().getProgramExecutable()))
+    {
+        context->validationError(entryPoint, GL_INVALID_OPERATION, kTransformFeedbackBufferMissing);
+        return false;
+    }
+
     return true;
 }
 

src/tests/gl_tests/TransformFeedbackTest.cpp

@@ -4080,6 +4080,31 @@ TEST_P(TransformFeedbackTest, BaseInstance)
     EXPECT_GL_NO_ERROR();
 }
 
+// Tests that deleting a buffer then resuming transform feedback produces an error.
+TEST_P(TransformFeedbackTest, ResumingTransformFeedbackAfterDeletebuffer)
+{
+    ANGLE_GL_PROGRAM_TRANSFORM_FEEDBACK(testProgram, essl1_shaders::vs::Simple(),
+                                        essl1_shaders::fs::Green(), {"gl_Position"},
+                                        GL_INTERLEAVED_ATTRIBS);
+    glUseProgram(testProgram);
+
+    std::vector<uint8_t> bufData(100, 0);
+
+    GLBuffer buf;
+    glBindBuffer(GL_PIXEL_UNPACK_BUFFER, buf);
+    glBufferData(GL_PIXEL_UNPACK_BUFFER, bufData.size(), bufData.data(), GL_DYNAMIC_COPY);
+    glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, buf);
+    glBeginTransformFeedback(GL_POINTS);
+    glPauseTransformFeedback();
+    glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+    buf.reset();
+    ASSERT_GL_NO_ERROR();
+
+    // Should produce an error because of a missing buffer binding.
+    glResumeTransformFeedback();
+    ASSERT_GL_ERROR(GL_INVALID_OPERATION);
+}
+
 GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(TransformFeedbackTest);
 ANGLE_INSTANTIATE_TEST_ES3(TransformFeedbackTest);