lua: fix SIGINT handling

Tarantool console quits if you type Ctrl+C.
This patch fixes console behavior on sending SIGINT. Console discards the current input on typing Ctrl+C and invites user to the new line.

In daemon mode the process will exit after receiving SIGINT.

Fixes #2717

src/main.cc

@@ -178,6 +178,31 @@ signal_cb(ev_loop *loop, struct ev_signal *w, int revents)
 	tarantool_exit(0);
 }
 
+static void
+signal_sigint_cb(ev_loop *loop, struct ev_signal *w, int revents)
+{
+	(void) loop;
+	(void) w;
+	(void) revents;
+
+	/**
+	 * If running in daemon mode, tarantool exits on SIGINT
+	 */
+	if (pid_file)
+		tarantool_exit(0);
+
+	/**
+ 	 * Setting prompt explicitly every time, cause of
+ 	 * need to return from search mode
+ 	 */
+	rl_set_prompt("tarantool>");
+	write(STDOUT_FILENO, "\n", sizeof("\n")-1);
+	RL_UNSETSTATE(RL_STATE_ISEARCH | RL_STATE_NSEARCH | RL_STATE_SEARCH);
+	rl_on_new_line();
+	rl_replace_line("", 0);
+	rl_redisplay();
+}
+
 static void
 signal_sigwinch_cb(ev_loop *loop, struct ev_signal *w, int revents)
 {
@@ -251,7 +276,7 @@ signal_init(void)
 	crash_signal_init();
 
 	ev_signal_init(&ev_sigs[0], sig_checkpoint, SIGUSR1);
-	ev_signal_init(&ev_sigs[1], signal_cb, SIGINT);
+	ev_signal_init(&ev_sigs[1], signal_sigint_cb, SIGINT);
 	ev_signal_init(&ev_sigs[2], signal_cb, SIGTERM);
 	ev_signal_init(&ev_sigs[3], signal_sigwinch_cb, SIGWINCH);
 	ev_signal_init(&ev_sigs[4], say_logrotate, SIGHUP);

test/app-tap/gh-2717-no-quit-sigint.test.lua

@@ -0,0 +1,33 @@
+#!/usr/bin/env tarantool
+
+local fiber = require('fiber')
+local tap = require('tap')
+local popen = require('popen')
+
+--
+-- gh-2717: tarantool console quit on sigint
+--
+
+local TARANTOOL_PATH = arg[-1]
+
+local res = tap.test('gh-2717', function(test)
+    print(TARANTOOL_PATH)
+
+    test:plan(2)
+    local prompt = 'tarantool>'
+    local ph = popen.shell(TARANTOOL_PATH .. ' -i', 'r')
+    assert(ph.pid, 'popen error while executing ' .. TARANTOOL_PATH)
+
+    fiber.sleep(0.5)
+    ph:signal(popen.signal.SIGINT)
+    fiber.sleep(0.5)
+
+    local output = ph:read()
+    test:like(ph:info().status.state, popen.state.ALIVE, 'process is still alive after SIGINT ')
+
+    ph:close()
+    print(output)
+    test:like(output, prompt .. ' \n' .. prompt, 'SIGINT doesn\'t kill tarantool in interactive mode ')
+    ph:close()
+end)
+os.exit(res and 0 or 1)