Fix editor spawning on null-string EDITOR and VISUAL.

  $ EDITOR= VISUAL= python -c 'import os; import sys; print os.environ'
  {..., 'EDITOR': '', ..., 'VISUAL': '', ...}

1 files changed, 3 insertions, 4 deletions

diff --git a/libbe/ui/util/editor.py b/libbe/ui/util/editor.py
index ce14365..1a430c7 100644
--- a/libbe/ui/util/editor.py
+++ b/libbe/ui/util/editor.py
@@ -64,13 +64,12 @@ def editor_string(comment=None, encoding=None):
     """
     if encoding == None:
         encoding = libbe.util.encoding.get_filesystem_encoding()
+    editor = None
     for name in ('VISUAL', 'EDITOR'):
-        try:
+        if name in os.environ and os.environ[name] != '':
             editor = os.environ[name]
             break
-        except KeyError:
-            pass
-    else:
+    if editor == None:
         raise CantFindEditor()
     fhandle, fname = tempfile.mkstemp()
     try: