Merge branch 'jk/add-e-kill-editor' into maint

"git add -e" did not allow the user to abort the operation by
killing the editor.

* jk/add-e-kill-editor:
  add: check return value of launch_editor

builtin/add.c

@@ -208,7 +208,8 @@ static int edit_patch(int argc, const char **argv, const char *prefix)
 	if (run_diff_files(&rev, 0))
 		die(_("Could not write patch"));
 
-	launch_editor(file, NULL, NULL);
+	if (launch_editor(file, NULL, NULL))
+		die(_("editing patch failed"));
 
 	if (stat(file, &st))
 		die_errno(_("Could not stat '%s'"), file);

t/t3702-add-edit.sh

@@ -118,4 +118,11 @@ test_expect_success 'add -e' '
 
 '
 
+test_expect_success 'add -e notices editor failure' '
+	git reset --hard &&
+	echo change >>file &&
+	test_must_fail env GIT_EDITOR=false git add -e &&
+	test_expect_code 1 git diff --exit-code
+'
+
 test_done