WebGL_compatibility: disallow client-side arrays

BUG=angleproject:1523

Change-Id: Icd207b2d94c1375c6f3189af42d55eac52b99603
Reviewed-on: https://chromium-review.googlesource.com/418398
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/tests/gl_tests/WebGLCompatibilityTest.cpp b/src/tests/gl_tests/WebGLCompatibilityTest.cpp
index ebc0efc..8464111 100644
--- a/src/tests/gl_tests/WebGLCompatibilityTest.cpp
+++ b/src/tests/gl_tests/WebGLCompatibilityTest.cpp
@@ -140,6 +140,78 @@
     glDeleteProgram(program);
 }
 
+// Test that client-side array buffers are forbidden in WebGL mode
+TEST_P(WebGLCompatibilityTest, ForbidsClientSideArrayBuffer)
+{
+    const std::string &vert =
+        "attribute vec3 a_pos;\n"
+        "void main()\n"
+        "{\n"
+        "    gl_Position = vec4(a_pos, 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);
+
+    GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
+    ASSERT_NE(-1, posLocation);
+    glUseProgram(program.get());
+
+    const auto &vertices = GetQuadVertices();
+    glVertexAttribPointer(posLocation, 3, GL_FLOAT, GL_FALSE, 0, vertices.data());
+    glEnableVertexAttribArray(posLocation);
+
+    ASSERT_GL_NO_ERROR();
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
+}
+
+// Test that client-side element array buffers are forbidden in WebGL mode
+TEST_P(WebGLCompatibilityTest, ForbidsClientSideElementBuffer)
+{
+    const std::string &vert =
+        "attribute vec3 a_pos;\n"
+        "void main()\n"
+        "{\n"
+        "    gl_Position = vec4(a_pos, 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);
+
+    GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
+    ASSERT_NE(-1, posLocation);
+    glUseProgram(program.get());
+
+    const auto &vertices = GetQuadVertices();
+
+    GLBuffer vertexBuffer;
+    glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer.get());
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices[0]) * vertices.size(), vertices.data(),
+                 GL_STATIC_DRAW);
+
+    glVertexAttribPointer(posLocation, 3, GL_FLOAT, GL_FALSE, 0, 0);
+    glEnableVertexAttribArray(posLocation);
+
+    const GLubyte indices[] = {0, 1, 2, 3, 4, 5};
+
+    ASSERT_GL_NO_ERROR();
+    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_BYTE, indices);
+    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
+}
+
 // Use this to select which configurations (e.g. which renderer, which GLES major version) these
 // tests should be run against.
 ANGLE_INSTANTIATE_TEST(WebGLCompatibilityTest,