Teach git var about GIT_EDITOR

Expose the command used by launch_editor() for scripts to use.
This should allow one to avoid searching for a proper editor
separately in each command.

git_editor(void) uses the logic to decide which editor to use
that used to live in launch_editor().  The function returns NULL
if there is no suitable editor; the caller is expected to issue
an error message when appropriate.

launch_editor() uses git_editor() and gives the error message the
same way as before when EDITOR is not set.

"git var GIT_EDITOR" gives the editor name, or an error message
when there is no appropriate one.

"git var -l" gives GIT_EDITOR=name only if there is an
appropriate editor.

Originally-submitted-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/editor.c b/editor.c
index 3f1375114..70618f106 100644
--- a/editor.c
+++ b/editor.c
@@ -2,7 +2,7 @@
 #include "strbuf.h"
 #include "run-command.h"
 
-int launch_editor(const char *path, struct strbuf *buffer, const char *const *env)
+const char *git_editor(void)
 {
 	const char *editor = getenv("GIT_EDITOR");
 	const char *terminal = getenv("TERM");
@@ -16,11 +16,21 @@ int launch_editor(const char *path, struct strbuf *buffer, const char *const *en
 		editor = getenv("EDITOR");
 
 	if (!editor && terminal_is_dumb)
-		return error("terminal is dumb, but EDITOR unset");
+		return NULL;
 
 	if (!editor)
 		editor = "vi";
 
+	return editor;
+}
+
+int launch_editor(const char *path, struct strbuf *buffer, const char *const *env)
+{
+	const char *editor = git_editor();
+
+	if (!editor)
+		return error("Terminal is dumb, but EDITOR unset");
+
 	if (strcmp(editor, ":")) {
 		size_t len = strlen(editor);
 		int i = 0;