[meld] build: Only update the MIME cache when DESTDIR isn't set

[Kai Willadsen <kaiw src gnome org>]

commit 913e5149ffc631b283f83eeb2a066b18f3faf877
Author: Kalev Lember <kalevlember gmail com>
Date:   Sat Mar 30 12:46:31 2013 +0100

    build: Only update the MIME cache when DESTDIR isn't set
    
    This adds a check to run update-mime-database / update-desktop-database
    only when DESTDIR isn't set.
    
    We don't want to include the generated cache files in downstream
    packages. These should be regenerated on the user's machine, not on the
    build host.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=696903

 Makefile |   27 +++++++++++++++++++++++----
 1 files changed, 23 insertions(+), 4 deletions(-)
---
diff --git a/Makefile b/Makefile
index dca92b3..b1e9cf9 100644
--- a/Makefile
+++ b/Makefile
@@ -92,8 +92,8 @@ install: $(addsuffix .install,$(SPECIALS)) meld.desktop
                $(DESTDIR)$(sharedir)/icons/HighContrast/scalable/apps/meld.svg
        $(MAKE) -C po install
        $(MAKE) -C help install
-       update-mime-database $(DESTDIR)$(sharedir)/mime
-       update-desktop-database $(DESTDIR)$(sharedir)/applications
+       $(update_mime_database)
+       $(update_desktop_database)
 
 meld.desktop: data/meld.desktop.in
        intltool-merge -d po data/meld.desktop.in data/meld.desktop
@@ -122,6 +122,25 @@ uninstall:
                $(sharedir)/pixmaps/meld.png
        $(MAKE) -C po uninstall
        $(MAKE) -C help uninstall
-       update-mime-database $(DESTDIR)$(sharedir)/mime
-       update-desktop-database $(DESTDIR)$(sharedir)/applications
+       $(update_mime_database)
+       $(update_desktop_database)
 
+update_mime_database_cmd = update-mime-database $(sharedir)/mime
+update_mime_database = \
+       @-if test -z "$(DESTDIR)"; then \
+               echo "Updating MIME database."; \
+               $(update_mime_database_cmd); \
+       else \
+               echo "*** MIME database not updated.  After (un)install, run this:"; \
+               echo "***   $(update_mime_database_cmd)"; \
+       fi
+
+update_desktop_database_cmd = update-desktop-database $(sharedir)/applications
+update_desktop_database = \
+       @-if test -z "$(DESTDIR)"; then \
+               echo "Updating desktop database."; \
+               $(update_desktop_database_cmd); \
+       else \
+               echo "*** Desktop database not updated.  After (un)install, run this:"; \
+               echo "***   $(update_desktop_database_cmd)"; \
+       fi