From df120e387c5194ce3d05ec5f848592d9af848872 Mon Sep 17 00:00:00 2001
From: Jonas Fonseca <jonas.fonseca@gmail.com>
Date: Sun, 9 Jul 2017 22:23:03 -0400
Subject: [PATCH] Fix suspension capability when calling out to external
 commands

Clear the terminal before calling out to an external command so the
altscreen won't mess up any downstream subshell management. Restore
terminal settings as per init_display when restoring. Reproducible with
example from[0]:

 - Run `tig status`
 - Press 'e' to open Vim
 - Press Ctrl-Z to suspend Vim
 - Run `fg`
 - Quit Vim

 [0] https://github.com/jonas/tig/issues/232#issuecomment-313790438

Refs: #232
---
 src/display.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/display.c b/src/display.c
index d86b0aea8..528bac991 100644
--- a/src/display.c
+++ b/src/display.c
@@ -57,6 +57,8 @@ open_external_viewer(const char *argv[], const char *dir, bool silent, bool conf
 		ok = io_run_bg(argv, dir);
 
 	} else {
+		clear();
+		refresh();
 		endwin();                  /* restore original tty modes */
 		ok = io_run_fg(argv, dir);
 		if (confirm || !ok) {
@@ -65,6 +67,11 @@ open_external_viewer(const char *argv[], const char *dir, bool silent, bool conf
 			fprintf(stderr, "Press Enter to continue");
 			getc(opt_tty);
 		}
+		nonl();		/* Disable conversion and detect newlines from input. */
+		raw();       /* Take input chars one at a time, no wait for \n */
+		noecho();       /* Don't echo input */
+		curs_set(0);
+		leaveok(stdscr, false);
 	}
 
 	if (watch_update(WATCH_EVENT_AFTER_COMMAND) && refresh) {
@@ -463,10 +470,7 @@ init_display(void)
 		die("Failed to register done_display");
 
 	/* Initialize the curses library */
-	if (!no_display && isatty(STDIN_FILENO)) {
-		cursed = !!initscr();
-		opt_tty = stdin;
-	} else {
+	{
 		/* Leave stdin and stdout alone when acting as a pager. */
 		FILE *out_tty;