intel: Fix inverted test for disabling flushing of front buffer output.

The comment disagreed with the code, and nicely drew my eyes to what was
going wrong.

Bug #21774 (blender)
Bug #21788 (readpix)

(cherry picked from master, commit fd65418f600874b05f902b622078b40bc1abb24a)

diff --git a/src/mesa/drivers/dri/intel/intel_context.c b/src/mesa/drivers/dri/intel/intel_context.c
index a40951abe398f577c7398995ea24d2ac16fa1dc6..50ae677d2034163c07cb595db96fb55753b3e0da 100644 (file)
--- a/src/mesa/drivers/dri/intel/intel_context.c
+++ b/src/mesa/drivers/dri/intel/intel_context.c
@@ -505,7 +505,7 @@ intel_flush(GLcontext *ctx, GLboolean needs_mi_flush)
          * each of N places that do rendering.  This has worse performances,
          * but it is much easier to get correct.
          */
-        if (intel->is_front_buffer_rendering) {
+        if (!intel->is_front_buffer_rendering) {
            intel->front_buffer_dirty = GL_FALSE;
         }
       }