nmcli: fix endless loop with --offline --ask

If --offline and --ask were used at the same time, and endless loop
showing the readline's prompt but without waiting for user's input
happened.

This was because when using --offline, all arguments are parsed and
resolved before running the g_main_loop. In nmc_readline_helper it was
checked that the main loop is running, so if g_main_loop_quit is called
we can stop waiting for user's input.

Fix this bug by continue polling for user input if the main loop is
running or if we are in offline mode.  Cancelling the user input is
still possible both in normal and offline mode with Ctrl+C or Ctrl+D.

Added a test case to verify that this still works after future changes.

src/nmcli/common.c

@@ -880,7 +880,8 @@ read_again:
     rl_got_line = FALSE;
     rl_callback_handler_install(prompt, readline_cb);
 
-    while (!rl_got_line && g_main_loop_is_running(loop) && !nmc_seen_sigint())
+    while (!rl_got_line && (g_main_loop_is_running(loop) || nmc_config->offline)
+           && !nmc_seen_sigint())
         g_main_context_iteration(NULL, TRUE);
 
     /* If Ctrl-C was detected, complete the line */
@@ -909,7 +910,7 @@ read_again:
         }
     } else if (!rl_string) {
         /* Ctrl-D, exit */
-        if (g_main_loop_is_running(loop))
+        if (g_main_loop_is_running(loop) || nmc_config->offline)
             nmc_exit();
     }
 

src/tests/client/test-client.py

@@ -703,11 +703,14 @@ class Util:
         return typ(pexp, valgrind_log)
 
     @staticmethod
-    def cmd_call_pexpect_nmcli(args):
+    def cmd_call_pexpect_nmcli(args, extra_env={}):
+        extra_env = extra_env.copy()
+        extra_env.update({"NO_COLOR": "1"})
+
         return Util.cmd_call_pexpect(
             ENV_NM_TEST_CLIENT_NMCLI_PATH,
             args,
-            {"NO_COLOR": "1"},
+            extra_env,
         )
 
 
@@ -2158,6 +2161,55 @@ class TestNmcli(unittest.TestCase):
         nmc.pexp.expect(pexpect.EOF)
         Util.valgrind_check_log(nmc.valgrind_log, "test_ask_mode")
 
+    @Util.skip_without_pexpect
+    @nm_test
+    def test_ask_offline(self):
+        # Make sure we're not using D-Bus
+        no_dbus_env = {
+            "DBUS_SYSTEM_BUS_ADDRESS": "very:invalid",
+            "DBUS_SESSION_BUS_ADDRESS": "very:invalid",
+        }
+
+        nmc = Util.cmd_call_pexpect_nmcli(
+            ["--offline", "--ask", "c", "add"], extra_env=no_dbus_env
+        )
+        nmc.pexp.expect("Connection type:")
+        nmc.pexp.sendline("ethernet")
+        nmc.pexp.expect("Interface name:")
+        nmc.pexp.sendline("eth0")
+        nmc.pexp.expect("There are 3 optional settings for Wired Ethernet.")
+        nmc.pexp.expect("Do you want to provide them\? \(yes/no\) \[yes]")
+        nmc.pexp.sendline("no")
+        nmc.pexp.expect("There are 2 optional settings for IPv4 protocol.")
+        nmc.pexp.expect("Do you want to provide them\? \(yes/no\) \[yes]")
+        nmc.pexp.sendline("no")
+        nmc.pexp.expect("There are 2 optional settings for IPv6 protocol.")
+        nmc.pexp.expect("Do you want to provide them\? \(yes/no\) \[yes]")
+        nmc.pexp.sendline("no")
+        nmc.pexp.expect("There are 4 optional settings for Proxy.")
+        nmc.pexp.expect("Do you want to provide them\? \(yes/no\) \[yes]")
+        nmc.pexp.sendline("no")
+        nmc.pexp.expect(
+            "\[connection\]\r\n"
+            + "id=ethernet\r\n"
+            + "uuid=.*\r\n"
+            + "type=ethernet\r\n"
+            + "interface-name=eth0\r\n"
+            + "\r\n"
+            + "\[ethernet\]\r\n"
+            + "\r\n"
+            + "\[ipv4\]\r\n"
+            + "method=auto\r\n"
+            + "\r\n"
+            + "\[ipv6\]\r\n"
+            + "addr-gen-mode=default\r\n"
+            + "method=auto\r\n"
+            + "\r\n"
+            + "\[proxy\]\r\n"
+        )
+        nmc.pexp.expect(pexpect.EOF)
+        Util.valgrind_check_log(nmc.valgrind_log, "test_ask_offline")
+
     @Util.skip_without_pexpect
     @nm_test
     def test_monitor(self):