Merge branch 'yn/git-jump-emacs'

"git jump" (in contrib/) learned to present the "quickfix list" to
its standard output (instead of letting it consumed by the editor
it invokes), and learned to also drive emacs/emacsclient.

* yn/git-jump-emacs:
  git-jump: invoke emacs/emacsclient
  git-jump: move valid-mode check earlier
  git-jump: add an optional argument '--stdout'

Author: gitster

contrib/git-jump/README

@@ -79,6 +79,14 @@ git jump grep -i foo_bar
 git config jump.grepCmd "ag --column"
 --------------------------------------------------
 
+You can use the optional argument '--stdout' to print the listing to
+standard output instead of feeding it to the editor. You can use the
+argument with M-x grep on Emacs:
+
+--------------------------------------------------
+# In Emacs, M-x grep and invoke "git jump --stdout <mode>"
+M-x grep<RET>git jump --stdout diff<RET>
+--------------------------------------------------
 
 Related Programs
 ----------------
@@ -100,7 +108,7 @@ Limitations
 -----------
 
 This script was written and tested with vim. Given that the quickfix
-format is the same as what gcc produces, I expect emacs users have a
+format is the same as what gcc produces, I expect other tools have a
 similar feature for iterating through the list, but I know nothing about
 how to activate it.
 

contrib/git-jump/git-jump

@@ -2,7 +2,7 @@
 
 usage() {
 	cat <<\EOF
-usage: git jump <mode> [<args>]
+usage: git jump [--stdout] <mode> [<args>]
 
 Jump to interesting elements in an editor.
 The <mode> parameter is one of:
@@ -15,12 +15,30 @@ grep: elements are grep hits. Arguments are given to git grep or, if
       configured, to the command in `jump.grepCmd`.
 
 ws: elements are whitespace errors. Arguments are given to diff --check.
+
+If the optional argument `--stdout` is given, print the quickfix
+lines to standard output instead of feeding it to the editor.
 EOF
 }
 
 open_editor() {
 	editor=`git var GIT_EDITOR`
-	eval "$editor -q \$1"
+	case "$editor" in
+	*emacs*)
+		# Supported editor values are:
+		# - emacs
+		# - emacsclient
+		# - emacsclient -t
+		#
+		# Wait for completion of the asynchronously executed process
+		# to avoid race conditions in case of "emacsclient".
+		eval "$editor --eval \"(let ((buf (grep \\\"cat \$1\\\"))) (pop-to-buffer buf) (select-frame-set-input-focus (selected-frame)) (while (get-buffer-process buf) (sleep-for 0.1)))\""
+		;;
+	*)
+		# assume anything else is vi-compatible
+		eval "$editor -q \$1"
+		;;
+	esac
 }
 
 mode_diff() {
@@ -64,15 +82,36 @@ mode_ws() {
 	git diff --check "$@"
 }
 
+use_stdout=
+while test $# -gt 0; do
+	case "$1" in
+	--stdout)
+		use_stdout=t
+		;;
+	--*)
+		usage >&2
+		exit 1
+		;;
+	*)
+		break
+		;;
+	esac
+	shift
+done
 if test $# -lt 1; then
 	usage >&2
 	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
+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"