fix(xmpp): guard NULL domain in autoping disco warning gate

g_ascii_strcasecmp() is not NULL-safe (unlike the g_strcmp0 it replaced), and connection_get_domain() can be NULL (init NULL, FREE_SET_NULL on teardown). A disco#info response racing a disconnect would dereference NULL. Capture the domain and skip the check when it is NULL.

src/command/cmd_ac.c

@@ -47,6 +47,7 @@ static char* _notify_autocomplete(ProfWin* window, const char* const input, gboo
 static char* _theme_autocomplete(ProfWin* window, const char* const input, gboolean previous);
 static char* _spellcheck_autocomplete(ProfWin* window, const char* const input, gboolean previous);
 static char* _autoaway_autocomplete(ProfWin* window, const char* const input, gboolean previous);
+static char* _autoping_autocomplete(ProfWin* window, const char* const input, gboolean previous);
 static char* _autoconnect_autocomplete(ProfWin* window, const char* const input, gboolean previous);
 static char* _account_autocomplete(ProfWin* window, const char* const input, gboolean previous);
 static char* _who_autocomplete(ProfWin* window, const char* const input, gboolean previous);
@@ -1056,6 +1057,7 @@ cmd_ac_init(void)
 
     autocomplete_add(autoping_ac, "set");
     autocomplete_add(autoping_ac, "timeout");
+    autocomplete_add(autoping_ac, "warning");
 
     autocomplete_add(plugins_ac, "install");
     autocomplete_add(plugins_ac, "update");
@@ -1407,6 +1409,7 @@ cmd_ac_init(void)
     g_hash_table_insert(ac_funcs, "/alias", _alias_autocomplete);
     g_hash_table_insert(ac_funcs, "/autoaway", _autoaway_autocomplete);
     g_hash_table_insert(ac_funcs, "/autoconnect", _autoconnect_autocomplete);
+    g_hash_table_insert(ac_funcs, "/autoping", _autoping_autocomplete);
     g_hash_table_insert(ac_funcs, "/avatar", _avatar_autocomplete);
     g_hash_table_insert(ac_funcs, "/ban", _ban_autocomplete);
     g_hash_table_insert(ac_funcs, "/blocked", _blocked_autocomplete);
@@ -1934,7 +1937,6 @@ _cmd_ac_complete_params(ProfWin* window, const char* const input, gboolean previ
         { "/prefs", prefs_ac },
         { "/disco", disco_ac },
         { "/room", room_ac },
-        { "/autoping", autoping_ac },
         { "/mainwin", winpos_ac },
         { "/inputwin", winpos_ac },
     };
@@ -4264,6 +4266,20 @@ _executable_autocomplete(ProfWin* window, const char* const input, gboolean prev
     return result;
 }
 
+static char*
+_autoping_autocomplete(ProfWin* window, const char* const input, gboolean previous)
+{
+    char* result = NULL;
+
+    result = autocomplete_param_with_ac(input, "/autoping", autoping_ac, TRUE, previous);
+    if (result) {
+        return result;
+    }
+
+    result = autocomplete_param_with_func(input, "/autoping warning", prefs_autocomplete_boolean_choice, previous, NULL);
+    return result;
+}
+
 static char*
 _lastactivity_autocomplete(ProfWin* window, const char* const input, gboolean previous)
 {

src/command/cmd_defs.c

@@ -1964,12 +1964,14 @@ static const struct cmd_t command_defs[] = {
               CMD_TAG_CONNECTION)
       CMD_SYN(
               "/autoping set <seconds>",
-              "/autoping timeout <seconds>")
+              "/autoping timeout <seconds>",
+              "/autoping warning on|off")
       CMD_DESC(
               "Set the interval between sending ping requests to the server to ensure the connection is kept alive.")
       CMD_ARGS(
               { "set <seconds>", "Number of seconds between sending pings, a value of 0 disables autoping." },
-              { "timeout <seconds>", "Seconds to wait for autoping responses, after which the connection is considered broken." })
+              { "timeout <seconds>", "Seconds to wait for autoping responses, after which the connection is considered broken." },
+              { "warning on|off", "Enable or disable autoping availability warning." })
     },
 
     { CMD_PREAMBLE("/ping",

src/command/cmd_funcs.c

@@ -6374,6 +6374,8 @@ cmd_autoping(ProfWin* window, const char* const command, gchar** args)
             cons_bad_cmd_usage(command);
         }
 
+    } else if (g_strcmp0(cmd, "warning") == 0) {
+        _cmd_set_boolean_preference(value, "Autoping availability warning", PREF_AUTOPING_WARNING);
     } else {
         cons_bad_cmd_usage(command);
     }

src/config/preferences.c

@@ -2290,6 +2290,7 @@ _get_group(preference_t pref)
     case PREF_TRAY:
     case PREF_TRAY_READ:
     case PREF_ADV_NOTIFY_DISCO_OR_VERSION:
+    case PREF_AUTOPING_WARNING:
         return PREF_GROUP_NOTIFICATIONS;
     case PREF_DBLOG:
     case PREF_CHLOG:
@@ -2646,6 +2647,8 @@ _get_key(preference_t pref)
         return "enabled";
     case PREF_SPELLCHECK_LANG:
         return "lang";
+    case PREF_AUTOPING_WARNING:
+        return "autoping.warning";
     default:
         return NULL;
     }
@@ -2699,6 +2702,7 @@ _get_default_boolean(preference_t pref)
     case PREF_MOOD:
     case PREF_STROPHE_SM_ENABLED:
     case PREF_STROPHE_SM_RESEND:
+    case PREF_AUTOPING_WARNING:
         return TRUE;
     case PREF_SPELLCHECK_ENABLE:
     case PREF_PGP_PUBKEY_AUTOIMPORT:

src/config/preferences.h

@@ -169,6 +169,7 @@ typedef enum {
     PREF_FORCE_ENCRYPTION_MODE,
     PREF_SPELLCHECK_ENABLE,
     PREF_SPELLCHECK_LANG,
+    PREF_AUTOPING_WARNING
 } preference_t;
 
 typedef struct prof_alias_t

src/ui/console.c

@@ -1703,6 +1703,11 @@ cons_notify_setting(void)
     else
         cons_show("Subscription requests (/notify sub) : OFF");
 
+    if (prefs_get_boolean(PREF_AUTOPING_WARNING))
+        cons_show("Autoping warning (/autoping warning): ON");
+    else
+        cons_show("Autoping warning (/autoping warning): OFF");
+
     gint remind_period = prefs_get_notify_remind();
     if (remind_period == 0) {
         cons_show("Reminder period (/notify remind)    : OFF");
@@ -2003,21 +2008,26 @@ cons_autoping_setting(void)
 {
     gint autoping_interval = prefs_get_autoping();
     if (autoping_interval == 0) {
-        cons_show("Autoping interval (/autoping)   : OFF");
+        cons_show("Autoping interval (/autoping)       : OFF");
     } else if (autoping_interval == 1) {
-        cons_show("Autoping interval (/autoping)   : 1 second");
+        cons_show("Autoping interval (/autoping)       : 1 second");
     } else {
-        cons_show("Autoping interval (/autoping)   : %d seconds", autoping_interval);
+        cons_show("Autoping interval (/autoping)       : %d seconds", autoping_interval);
     }
 
     gint autoping_timeout = prefs_get_autoping_timeout();
     if (autoping_timeout == 0) {
-        cons_show("Autoping timeout (/autoping)    : OFF");
+        cons_show("Autoping timeout (/autoping)        : OFF");
     } else if (autoping_timeout == 1) {
-        cons_show("Autoping timeout (/autoping)    : 1 second");
+        cons_show("Autoping timeout (/autoping)        : 1 second");
     } else {
-        cons_show("Autoping timeout (/autoping)    : %d seconds", autoping_timeout);
+        cons_show("Autoping timeout (/autoping)        : %d seconds", autoping_timeout);
     }
+
+    if (prefs_get_boolean(PREF_AUTOPING_WARNING))
+        cons_show("Autoping warning (/autoping warning): ON");
+    else
+        cons_show("Autoping warning (/autoping warning): OFF");
 }
 
 void

src/xmpp/iq.c

@@ -99,6 +99,7 @@ static void _disco_items_result_handler(xmpp_stanza_t* const stanza);
 static void _last_activity_get_handler(xmpp_stanza_t* const stanza);
 static void _version_get_handler(xmpp_stanza_t* const stanza);
 static void _ping_get_handler(xmpp_stanza_t* const stanza);
+static void _disco_autoping_warning_message(GHashTable* features);
 
 static int _version_result_id_handler(xmpp_stanza_t* const stanza, void* const userdata);
 static int _disco_info_response_id_handler(xmpp_stanza_t* const stanza, void* const userdata);
@@ -2429,6 +2430,12 @@ _disco_info_response_id_handler_onconnect(xmpp_stanza_t* const stanza, void* con
             }
             child = xmpp_stanza_get_next(child);
         }
+
+        // Prevent repetitions by avoiding checks of disco items (from connection_set_disco_items)
+        const char* domain = connection_get_domain();
+        if (from && domain && g_ascii_strcasecmp(from, domain) == 0) {
+            _disco_autoping_warning_message(features);
+        }
     }
 
     connection_features_received(from);
@@ -2436,6 +2443,21 @@ _disco_info_response_id_handler_onconnect(xmpp_stanza_t* const stanza, void* con
     return 0;
 }
 
+static void
+_disco_autoping_warning_message(GHashTable* features)
+{
+    gboolean server_supports_ping = g_hash_table_contains(features, "urn:xmpp:ping");
+    gboolean user_prefers_warning = prefs_get_boolean(PREF_AUTOPING_WARNING);
+    gboolean is_autoping_enabled = prefs_get_autoping() != 0;
+
+    if (!is_autoping_enabled && server_supports_ping && user_prefers_warning) {
+        cons_show("This server supports XEP-0199: XMPP Ping (better keepalive detection),\n"
+                  "but autoping feature is currently disabled in settings.\n"
+                  "Consider enabling it (e.g., `/autoping set 30`) for improved connection stability.\n"
+                  "Use `/autoping warning off` to disable this message.");
+    }
+}
+
 static int
 _http_upload_response_id_handler(xmpp_stanza_t* const stanza, void* const userdata)
 {

tests/functionaltests/functionaltests.c

@@ -150,6 +150,14 @@ main(int argc, char* argv[])
         PROF_FUNC_TEST(autoping_sends_ping_after_interval),
         PROF_FUNC_TEST(autoping_server_not_supporting_ping),
 
+        /* Autoping availability warning - negative cases wait ~3s */
+        PROF_FUNC_TEST(autoping_warning_shown_when_disabled),
+        PROF_FUNC_TEST(autoping_warning_not_shown_when_server_unsupported),
+        PROF_FUNC_TEST(autoping_warning_not_shown_when_autoping_enabled),
+        PROF_FUNC_TEST(autoping_warning_not_shown_when_user_disabled),
+        PROF_FUNC_TEST(autoping_warning_not_shown_for_user_jid),
+        PROF_FUNC_TEST(autoping_warning_not_shown_for_subdomain_service),
+
         /* Service Discovery - XEP-0030 */
         PROF_FUNC_TEST(disco_info_shows_identity),
         PROF_FUNC_TEST(disco_info_shows_features),

tests/functionaltests/test_autoping.c

@@ -112,3 +112,144 @@ autoping_server_not_supporting_ping(void** state)
     // Should show error about ping not being supported
     assert_true(prof_output_regex("Server ping not supported"));
 }
+
+/*
+ * Autoping availability warning.
+ *
+ * The warning fires from the on-connect disco handler, so the three inputs
+ * (server ping support, autoping interval, warning preference) must all be
+ * set before prof_connect().
+ */
+
+/* Stable substring of the warning text emitted by iq.c. */
+#define AUTOPING_WARNING_MATCH "This server supports XEP-0199"
+
+static void
+_stub_server_disco(gboolean with_ping)
+{
+    if (with_ping) {
+        stbbr_for_query("http://jabber.org/protocol/disco#info",
+            "<iq to='stabber@localhost/profanity' type='result' from='localhost'>"
+                "<query xmlns='http://jabber.org/protocol/disco#info'>"
+                    "<identity category='server' type='im' name='Stabber'/>"
+                    "<feature var='urn:xmpp:ping'/>"
+                "</query>"
+            "</iq>"
+        );
+    } else {
+        stbbr_for_query("http://jabber.org/protocol/disco#info",
+            "<iq to='stabber@localhost/profanity' type='result' from='localhost'>"
+                "<query xmlns='http://jabber.org/protocol/disco#info'>"
+                    "<identity category='server' type='im' name='Stabber'/>"
+                "</query>"
+            "</iq>"
+        );
+    }
+}
+
+void
+autoping_warning_shown_when_disabled(void** state)
+{
+    // All conditions met: server supports ping, autoping off, warning on (default).
+    _stub_server_disco(TRUE);
+
+    prof_input("/autoping set 0");
+    assert_true(prof_output_exact("Autoping disabled."));
+
+    prof_connect();
+
+    assert_true(prof_output_regex(AUTOPING_WARNING_MATCH));
+}
+
+void
+autoping_warning_not_shown_when_server_unsupported(void** state)
+{
+    // Server does not advertise urn:xmpp:ping -> no warning even with autoping off.
+    _stub_server_disco(FALSE);
+
+    prof_input("/autoping set 0");
+    assert_true(prof_output_exact("Autoping disabled."));
+
+    prof_connect();
+
+    prof_timeout(NEGATIVE_ASSERT_TIMEOUT);
+    assert_false(prof_output_regex(AUTOPING_WARNING_MATCH));
+}
+
+void
+autoping_warning_not_shown_when_autoping_enabled(void** state)
+{
+    // Warning is suppressed while autoping is enabled.
+    _stub_server_disco(TRUE);
+
+    prof_input("/autoping set 30");
+    assert_true(prof_output_exact("Autoping interval set to 30 seconds."));
+
+    prof_connect();
+
+    prof_timeout(NEGATIVE_ASSERT_TIMEOUT);
+    assert_false(prof_output_regex(AUTOPING_WARNING_MATCH));
+}
+
+void
+autoping_warning_not_shown_when_user_disabled(void** state)
+{
+    // User opted out -> no warning.
+    _stub_server_disco(TRUE);
+
+    prof_input("/autoping set 0");
+    assert_true(prof_output_exact("Autoping disabled."));
+
+    prof_input("/autoping warning off");
+    assert_true(prof_output_exact("Autoping availability warning disabled."));
+
+    prof_connect();
+
+    prof_timeout(NEGATIVE_ASSERT_TIMEOUT);
+    assert_false(prof_output_regex(AUTOPING_WARNING_MATCH));
+}
+
+void
+autoping_warning_not_shown_for_user_jid(void** state)
+{
+    // disco#info from a user JID (with '@') should not trigger the warning,
+    // only server responses (no '@') should.
+    stbbr_for_query("http://jabber.org/protocol/disco#info",
+        "<iq to='stabber@localhost/profanity' type='result' from='buddy1@localhost'>"
+            "<query xmlns='http://jabber.org/protocol/disco#info'>"
+                "<identity category='person' type='chat' name='Buddy1'/>"
+                "<feature var='urn:xmpp:ping'/>"
+            "</query>"
+        "</iq>"
+    );
+
+    prof_input("/autoping set 0");
+    assert_true(prof_output_exact("Autoping disabled."));
+
+    prof_connect();
+
+    prof_timeout(NEGATIVE_ASSERT_TIMEOUT);
+    assert_false(prof_output_regex(AUTOPING_WARNING_MATCH));
+}
+
+void
+autoping_warning_not_shown_for_subdomain_service(void** state)
+{
+    // disco#info from a subdomain service should not trigger the warning, only the server's own domain should
+    stbbr_for_query("http://jabber.org/protocol/disco#info",
+        "<iq to='stabber@localhost/profanity' type='result' from='conf.localhost'>"
+            "<query xmlns='http://jabber.org/protocol/disco#info'>"
+                "<identity category='conference' type='text' name='Conference Service'/>"
+                "<feature var='urn:xmpp:ping'/>"
+            "</query>"
+        "</iq>"
+    );
+
+    prof_input("/autoping set 0");
+    assert_true(prof_output_exact("Autoping disabled."));
+
+    prof_connect();
+
+    prof_timeout(NEGATIVE_ASSERT_TIMEOUT);
+    assert_false(prof_output_regex(AUTOPING_WARNING_MATCH));
+}

tests/functionaltests/test_autoping.h

@@ -4,3 +4,9 @@ void autoping_timeout_set(void** state);
 void autoping_timeout_zero_disables(void** state);
 void autoping_sends_ping_after_interval(void** state);
 void autoping_server_not_supporting_ping(void** state);
+void autoping_warning_shown_when_disabled(void** state);
+void autoping_warning_not_shown_when_server_unsupported(void** state);
+void autoping_warning_not_shown_when_autoping_enabled(void** state);
+void autoping_warning_not_shown_when_user_disabled(void** state);
+void autoping_warning_not_shown_for_user_jid(void** state);
+void autoping_warning_not_shown_for_subdomain_service(void** state);