Respect locale environment variables on darwin.
In python 2.4+ on darwin, locale.getpreferredencoding() returns
mac-roman regardless of what LC_CTYPE, LANG etc are set to. This can
produce hard-to-notice conversion errors if input text is not in
mac-roman. So this patch overrides it with setlocale/getlocale if the
environment has been customized, on the assumption that the user has
done so deliberately.
% init
% commit
adding base
% qnew mqbase
% qrefresh
% qdiff
diff -r 67e992f2c4f3 base
--- a/base
+++ b/base
@@ -1,1 +1,1 @@ base
-base
+patched
% qdiff dirname
diff -r 67e992f2c4f3 base
--- a/base
+++ b/base
@@ -1,1 +1,1 @@ base
-base
+patched