From 0838c87dacdb8355ca9a2d7a812d18a58087aac8 Mon Sep 17 00:00:00 2001
From: Markus Wick <markus@selfnet.de>
Date: Sat, 19 May 2018 15:40:46 +0200
Subject: [PATCH] gl_stream_buffer: Only flush the host buffer if anything was
 written.

This might happen in the new TBO upload path.
---
 src/video_core/renderer_opengl/gl_stream_buffer.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/video_core/renderer_opengl/gl_stream_buffer.cpp b/src/video_core/renderer_opengl/gl_stream_buffer.cpp
index 1957cfbcc..03a8ed8b7 100644
--- a/src/video_core/renderer_opengl/gl_stream_buffer.cpp
+++ b/src/video_core/renderer_opengl/gl_stream_buffer.cpp
@@ -87,7 +87,7 @@ std::tuple<u8*, GLintptr, bool> OGLStreamBuffer::Map(GLsizeiptr size, GLintptr a
 void OGLStreamBuffer::Unmap(GLsizeiptr size) {
     ASSERT(size <= mapped_size);
 
-    if (!coherent) {
+    if (!coherent && size > 0) {
         glFlushMappedBufferRange(gl_target, buffer_pos - mapped_offset, size);
     }