[gegl] pixelize: fix potential glitches

[Thomas Manni <tmanni src gnome org>]

commit a941184b5f85b8170f90e76ef8ea90920c1e9d18
Author: Thomas Manni <thomas manni free fr>
Date:   Mon Aug 5 12:17:10 2019 +0200

    pixelize: fix potential glitches
    
    In set_rectangle_noalloc function, iterate over the output with
    GEGL_ACCESS_READWRITE instead of GEGL_ACCESS_WRITE since we only fill
    pixels inside the shape and need to keep already filled background pixels.

 operations/common/pixelize.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/operations/common/pixelize.c b/operations/common/pixelize.c
index 831db725c..4c628b9ca 100644
--- a/operations/common/pixelize.c
+++ b/operations/common/pixelize.c
@@ -267,7 +267,7 @@ set_rectangle_noalloc (GeglBuffer      *output,
       gegl_color_get_pixel (color, format, col);
 
       gi = gegl_buffer_iterator_new (output, rect, 0, format,
-                                     GEGL_ACCESS_WRITE, GEGL_ABYSS_CLAMP, 1);
+                                     GEGL_ACCESS_READWRITE, GEGL_ABYSS_CLAMP, 1);
 
       while (gegl_buffer_iterator_next (gi))
         {