[meld] bin/meld: Don't pass git environment vars on to children (bgo#741142)

[Kai Willadsen <kaiw src gnome org>]

commit f3002310da1c5db3bfe0f093c898815d712f39a9
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Dec 13 06:21:43 2014 +1000

    bin/meld: Don't pass git environment vars on to children (bgo#741142)
    
    GIT_DIR and GIT_WORK_TREE are somewhat-helpfully set by some helper
    tools such as git-gui. However, since we are quite good about setting
    the cwd everywhere we call our git helpers, this sometimes messes with
    things for us when invoking from subdirectories and whatnot. Since
    these vars aren't helping us anyway, we'll just unset them in Meld's
    environment altogether.

 bin/meld |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/bin/meld b/bin/meld
index 0be179d..060b15e 100755
--- a/bin/meld
+++ b/bin/meld
@@ -252,12 +252,23 @@ def setup_logging():
     log.addHandler(handler)
 
 
+def environment_hacks():
+    # We manage cwd ourselves for git operations, and GIT_DIR in particular
+    # can mess with this when set.
+    for var in ('GIT_DIR', 'GIT_WORK_TREE'):
+        try:
+            del os.environ[var]
+        except KeyError:
+            pass
+
+
 if __name__ == '__main__':
     setup_logging()
     disable_stdout_buffering()
     check_requirements()
     setup_settings()
     setup_resources()
+    environment_hacks()
 
     import meld.meldapp
     if sys.platform != 'win32':