[meld] Fix uninstalled use with modules that change __file__

[Kai Willadsen <kaiw src gnome org>]

commit bafe7db31481f6cb2c2a013da5ded93affae43fe
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Apr 28 08:05:45 2012 +1000

    Fix uninstalled use with modules that change __file__
    
    Some modules such as runpy (and by extension, modules such as trace
    that use runpy) alter the value of __file__, which causes our
    directory-location logic to fail. This patch tries to detect this by
    checking the value of __file__ and falling back to sys.argv[0] when it
    looks to be dodgy.
    
    Based on a patch and suggestions from Peter Tyser.

 bin/meld |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/bin/meld b/bin/meld
index 71e9d43..e5e8250 100755
--- a/bin/meld
+++ b/bin/meld
@@ -54,7 +54,13 @@ except ValueError:
     profiling = False
 
 # Support running from an uninstalled version
-melddir = os.path.abspath(os.path.join(os.path.dirname(os.path.realpath(__file__)), ".."))
+if os.path.basename(__file__) == "meld":
+    self_path = os.path.realpath(__file__)
+else:
+    # Hack around an issue with some modules s.a. runpy/trace in Python <2.7
+    self_path = os.path.realpath(sys.argv[0])
+melddir = os.path.abspath(os.path.join(os.path.dirname(self_path), ".."))
+
 if os.path.exists(os.path.join(melddir, "meld.doap")):
     sys.path[0:0] = [melddir]
 else: