[gcalctool] Allow explicit superscript minus

[Robert Ancell <rancell src gnome org>]

commit 543a3712ad65d26d8d4e16564fe14869f1c883d5
Author: Robert Ancell <robert ancell gmail com>
Date:   Tue Feb 23 12:17:59 2010 +1100

    Allow explicit superscript minus

 src/gtk.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/src/gtk.c b/src/gtk.c
index 2bede45..2ce6a5b 100644
--- a/src/gtk.c
+++ b/src/gtk.c
@@ -1392,6 +1392,13 @@ main_window_key_press_cb(GtkWidget *widget, GdkEventKey *event)
         }
     }
 
+    if (state == GDK_CONTROL_MASK && event->keyval == GDK_minus) 
+    {
+        do_text("â?»");
+        X.can_super_minus = FALSE;
+        return TRUE;
+    }
+
     if (state != 0)
         return FALSE;