Merge branch 'po/insn-editor'

* po/insn-editor:
  "rebase -i": support special-purpose editor to edit insn sheet

Documentation/config.txt

@@ -474,6 +474,12 @@ core.editor::
 	variable when it is set, and the environment variable
 	`GIT_EDITOR` is not set.  See linkgit:git-var[1].
 
+sequence.editor::
+	Text editor used by `git rebase -i` for editing the rebase insn file.
+	The value is meant to be interpreted by the shell when it is used.
+	It can be overridden by the `GIT_SEQUENCE_EDITOR` environment variable.
+	When not configured the default commit message editor is used instead.
+
 core.pager::
 	The command that git will use to paginate output.  Can
 	be overridden with the `GIT_PAGER` environment

git-rebase--interactive.sh

@@ -161,6 +161,19 @@ do_with_author () {
 	)
 }
 
+git_sequence_editor () {
+	if test -z "$GIT_SEQUENCE_EDITOR"
+	then
+		GIT_SEQUENCE_EDITOR="$(git config sequence.editor)"
+		if [ -z "$GIT_SEQUENCE_EDITOR" ]
+		then
+			GIT_SEQUENCE_EDITOR="$(git var GIT_EDITOR)" || return $?
+		fi
+	fi
+
+	eval "$GIT_SEQUENCE_EDITOR" '"$@"'
+}
+
 pick_one () {
 	ff=--ff
 	case "$1" in -n) sha1=$2; ff= ;; *) sha1=$1 ;; esac
@@ -832,7 +845,7 @@ has_action "$todo" ||
 	die_abort "Nothing to do"
 
 cp "$todo" "$todo".backup
-git_editor "$todo" ||
+git_sequence_editor "$todo" ||
 	die_abort "Could not execute editor"
 
 has_action "$todo" ||