[gimp] Modified a comment in more detail.

[Jehan <jehanp src gnome org>]

commit b405b0364c4a9a173653092c1b21ef076a0b355a
Author: ONO Yoshio <ohtsuka yoshio gmail com>
Date:   Tue Jul 31 08:56:19 2018 +0900

    Modified a comment in more detail.

 app/tools/gimptexttool-editor.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/app/tools/gimptexttool-editor.c b/app/tools/gimptexttool-editor.c
index 4921cb2f9c..b2d4c46ec6 100644
--- a/app/tools/gimptexttool-editor.c
+++ b/app/tools/gimptexttool-editor.c
@@ -635,7 +635,9 @@ gimp_text_tool_editor_get_cursor_rect (GimpTextTool   *text_tool,
     {
       pango_layout_index_to_pos (layout, cursor_index, cursor_rect);
 
-      /* Avoid pango bug ? */
+      /* pango_layout_index_to_pos() returns wrong position, if gravity is west
+       * and cursor is at end of line. Avoid this behavior. (pango 1.42.1)
+       */
       if (pango_context_get_base_gravity (context) == PANGO_GRAVITY_WEST &&
           cursor_rect->width == 0)
         pango_layout_get_cursor_pos (layout, cursor_index, cursor_rect, NULL);