Vulkan: Fix crash with 0-sized element buffer

src/libANGLE/renderer/vulkan/VertexArrayVk.cpp

@@ -448,7 +448,7 @@ angle::Result VertexArrayVk::syncState(const gl::Context *context,
             case gl::VertexArray::DIRTY_BIT_ELEMENT_ARRAY_BUFFER_DATA:
             {
                 gl::Buffer *bufferGL = mState.getElementArrayBuffer();
-                if (bufferGL)
+                if (bufferGL && bufferGL->getSize() > 0)
                 {
                     // Note that just updating buffer data may still result in a new
                     // vk::BufferHelper allocation.

src/tests/gl_tests/StateChangeTest.cpp

@@ -6075,6 +6075,21 @@ void main()
     EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
 }
 
+// Test that glDrawArrays when an empty-sized element array buffer is bound doesn't crash.
+// Regression test for crbug.com/1172577.
+TEST_P(SimpleStateChangeTest, DrawArraysWithZeroSizedElementArrayBuffer)
+{
+    ANGLE_GL_PROGRAM(greenProgram, essl1_shaders::vs::Simple(), essl1_shaders::fs::Green());
+
+    GLBuffer indexBuffer;
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, 0, nullptr, GL_DYNAMIC_DRAW);
+    drawQuad(greenProgram, essl1_shaders::PositionAttrib(), 0.0f);
+    ASSERT_GL_NO_ERROR();
+
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
+}
+
 // Validates GL_RASTERIZER_DISCARD state is tracked correctly
 TEST_P(SimpleStateChangeTestES3, RasterizerDiscardState)
 {