[meld] dirdiff: Add Enter/Return as an accelerator for Compare (#262)

[Kai Willadsen <kaiw src gnome org>]

commit d47a58706a21f9c9aaa7f8b25fe2818f02fc88b5
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Tue Jan 1 09:47:59 2019 +1000

    dirdiff: Add Enter/Return as an accelerator for Compare (#262)
    
    The intention here was for this to essentially be a documentation
    change, i.e., so that users can see that the shortcut exists. In
    reality, this is a behaviour change when hitting enter on a folder row.
    
    Previously, this would expand/collapse the row because it was a treeview
    row activation signal and that seemed like a reasonable thing to do.
    This is still what will happen on actual row activation (i.e., double-
    clicking a folder row), but now hitting enter will activate the Compare
    action and will create a new folder comparison when activating a folder
    row.
    
    I don't think either of these options are obviously better than the
    other, so I'm going to go with this new behaviour for now.

 data/ui/dirdiff.ui | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/data/ui/dirdiff.ui b/data/ui/dirdiff.ui
index b5b3a12e..70840405 100644
--- a/data/ui/dirdiff.ui
+++ b/data/ui/dirdiff.ui
@@ -11,6 +11,7 @@
         <property name="is_important">True</property>
         <signal name="activate" handler="on_button_diff_clicked" swapped="no"/>
       </object>
+      <accelerator key="Return"/>
     </child>
     <child>
       <object class="GtkAction" id="DirCollapseRecursively">