This patch fixes three issues with "notmuch-mutt tag":

1. The message_id was not shell quoted.
   Thanks to Jason Miller for the bug report and patch.

2. The tags passed into tag_action() were not being properly quoted.
   The "join before shell_quote" was combining multiple tags into a
   single argument to notmuch tag: '+one -two -three' instead of
   '+one' '-two' '-three'.

3. A "--" was added between the tags and search-term as shown in the
   current notmuch-tag man page.

Thanks to Tomi Ollila for suggesting the simple fix of using
the list form of system(), which bypasses the shell.
---
 contrib/notmuch-mutt/notmuch-mutt | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/contrib/notmuch-mutt/notmuch-mutt b/contrib/notmuch-mutt/notmuch-mutt
index c69b35c..4969e4b 100755
--- a/contrib/notmuch-mutt/notmuch-mutt
+++ b/contrib/notmuch-mutt/notmuch-mutt
@@ -113,9 +113,7 @@ sub tag_action(@) {
     my $mid = get_message_id();
     defined $mid or die "notmuch-mutt: cannot find Message-Id, abort.\n";
 
-    system("notmuch tag "
-	   . shell_quote(join(' ', @_))
-	   . " id:$mid");
+    system("notmuch", "tag", @_, "--", "id:$mid");
 }
 
 sub die_usage() {
-- 
1.8.4.rc3