Fix (unreported) Image Editor UI drawing too dark

Caused by rBf0221ff6674f.

Only draw the Image buffer itself in display space.

Differential Revision: https://developer.blender.org/D7449

source/blender/editors/space_image/image_draw.c

@@ -575,6 +575,9 @@ static void draw_image_buffer(const bContext *C,
                               float zoomx,
                               float zoomy)
 {
+  /* Image are still drawn in display space. */
+  glDisable(GL_FRAMEBUFFER_SRGB);
+
   int x, y;
   int sima_flag = sima->flag & ED_space_image_get_display_channel_mask(ibuf);
 
@@ -666,6 +669,8 @@ static void draw_image_buffer(const bContext *C,
       GPU_blend(false);
     }
   }
+
+  glEnable(GL_FRAMEBUFFER_SRGB);
 }
 
 static void draw_image_buffer_repeated(const bContext *C,

source/blender/editors/space_image/space_image.c

@@ -669,14 +669,9 @@ static void image_main_region_draw(const bContext *C, ARegion *region)
   /* we set view2d from own zoom and offset each time */
   image_main_region_set_view2d(sima, region);
 
-  /* Image are still drawn in display space. */
-  glDisable(GL_FRAMEBUFFER_SRGB);
-
   /* we draw image in pixelspace */
   draw_image_main(C, region);
 
-  glEnable(GL_FRAMEBUFFER_SRGB);
-
   /* and uvs in 0.0-1.0 space */
   UI_view2d_view_ortho(v2d);