git-jump: move valid-mode check earlier

We check if the "mode" argument supplied by the user is valid by seeing
if we have a mode_$mode function defined. But we don't do that until
after creating the tempfile. This is wasteful (we create a tempfile but
never use it), and makes it harder to add new options (the recent stdout
option exits before creating the tempfile, so it misses the check and
"git jump --stdout foo" will produce "git-jump: 92: mode_foo: not found"
rather than the regular usage message).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/git-jump/git-jump

@@ -88,6 +88,8 @@ if test $# -lt 1; then
 	exit 1
 fi
 mode=$1; shift
+type "mode_$mode" >/dev/null 2>&1 || { usage >&2; exit 1; }
+
 if test "$use_stdout" = "t"; then
 	"mode_$mode" "$@"
 	exit 0
@@ -95,7 +97,6 @@ fi
 
 trap 'rm -f "$tmp"' 0 1 2 3 15
 tmp=`mktemp -t git-jump.XXXXXX` || exit 1
-type "mode_$mode" >/dev/null 2>&1 || { usage >&2; exit 1; }
 "mode_$mode" "$@" >"$tmp"
 test -s "$tmp" || exit 0
 open_editor "$tmp"