[gimp/gimp-2-8] app: enable scale image's resolution chain button only if xres == yres

[Michael Natterer <mitch src gnome org>]

commit 1f7df343dc2c0160c7b6255ed0aab12be8c8ec11
Author: Michael Natterer <mitch gimp org>
Date:   Fri Apr 18 19:17:56 2014 +0200

    app: enable scale image's resolution chain button only if xres == yres
    
    (the edit_resolution feature of GimpSizeBox is currently used
    only by the scale image dialog)
    
    (cherry picked from commit be8f43ff06e33303ec3de3ac2ed343114d6c2af5)

 app/widgets/gimpsizebox.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/app/widgets/gimpsizebox.c b/app/widgets/gimpsizebox.c
index 12adcc4..b45326e 100644
--- a/app/widgets/gimpsizebox.c
+++ b/app/widgets/gimpsizebox.c
@@ -244,14 +244,19 @@ gimp_size_box_constructed (GObject *object)
 
   if (box->edit_resolution)
     {
+      gboolean chain_active;
+
       hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
       gtk_box_pack_start (GTK_BOX (box), hbox, FALSE, FALSE, 0);
       gtk_widget_show (hbox);
 
+      chain_active = ABS (box->xresolution -
+                          box->yresolution) < GIMP_MIN_RESOLUTION;
+
       entry = gimp_coordinates_new (box->resolution_unit, _("pixels/%a"),
                                     FALSE, FALSE, SB_WIDTH,
                                     GIMP_SIZE_ENTRY_UPDATE_RESOLUTION,
-                                    TRUE, FALSE,
+                                    chain_active, FALSE,
                                     _("_X resolution:"),
                                     box->xresolution, 1.0,
                                     1, 1, 1, 10,