fix(ui): add authoritative suspend flag gating redraws over the editor

Builds on the upstream "guard terminal writes while suspended" fix. That
fix keeps isendwin() a valid "suspended" signal by guarding stray writes
(_inp_write, beep, flash) so the existing isendwin() checks in
ui_update/ui_resize/ui_redraw hold. That is correct but fail-open: any
future unguarded doupdate()/refresh() reachable during an editor session
clears isendwin() and the ~10Hz ui_update() repaints over the editor
again (the original bug class).

Track suspension explicitly with a ui_suspended flag set in
ui_suspend()/ui_resume() and gate the three redraw entry points on
ui_suspended || isendwin() via _ui_redraw_suspended(). The flag is set
exactly at the suspend/resume boundary, so the dominant repaint path
fails safe regardless of isendwin() flapping. isendwin() is kept in the
condition for the shutdown/closed-screen case.

src/event/server_events.c

@@ -341,7 +341,7 @@ sv_ev_room_message(ProfMessage* message)
         status_bar_active(num, WIN_MUC, mucwin->roomjid);
 
         if ((g_strcmp0(mynick, message->from_jid->resourcepart) != 0) && (prefs_get_boolean(PREF_BEEP))) {
-            beep();
+            ui_beep();
         }
 
         // not currently on groupchat window
@@ -349,7 +349,7 @@ sv_ev_room_message(ProfMessage* message)
         status_bar_new(num, WIN_MUC, mucwin->roomjid);
 
         if ((g_strcmp0(mynick, message->from_jid->resourcepart) != 0) && (prefs_get_boolean(PREF_FLASH))) {
-            flash();
+            ui_flash();
         }
 
         cons_show_incoming_room_message(message->from_jid->resourcepart, mucwin->roomjid, num, mention, triggers, mucwin->unread, window);

src/ui/chatwin.c

@@ -327,7 +327,7 @@ chatwin_incoming_msg(ProfChatWin* chatwin, ProfMessage* message, gboolean win_cr
             cons_show_incoming_message(display_name, num, chatwin->unread, window);
 
             if (prefs_get_boolean(PREF_FLASH)) {
-                flash();
+                ui_flash();
             }
 
             chatwin->unread++;
@@ -364,7 +364,7 @@ chatwin_incoming_msg(ProfChatWin* chatwin, ProfMessage* message, gboolean win_cr
         wins_add_quotes_ac(window, message->plain, FALSE);
 
         if (prefs_get_boolean(PREF_BEEP)) {
-            beep();
+            ui_beep();
         }
     }
 

src/ui/core.c

@@ -65,7 +65,9 @@ static Display* display;
 static void _ui_draw_term_title(void);
 
 // Skip drawing while an external editor is active (ui_suspended) or after the
-// screen has been closed (endwin).
+// screen has been closed (endwin). The flag is authoritative and does not rely
+// on isendwin() staying TRUE, which a stray doupdate() during the session could
+// otherwise clear.
 static gboolean
 _ui_redraw_suspended(void)
 {
@@ -189,6 +191,7 @@ ui_suspend(void)
 {
     ui_suspended = TRUE;
     inp_suspend();
+    doupdate();
     endwin();
 }
 
@@ -200,6 +203,22 @@ ui_resume(void)
     inp_resume();
 }
 
+void
+ui_beep(void)
+{
+    if (!isendwin()) {
+        beep();
+    }
+}
+
+void
+ui_flash(void)
+{
+    if (!isendwin()) {
+        flash();
+    }
+}
+
 void
 ui_resize(void)
 {

src/ui/inputwin.c

@@ -311,7 +311,10 @@ inp_get_line(void)
     werase(inp_win);
     wmove(inp_win, 0, 0);
     _inp_win_update_virtual();
-    doupdate();
+    // Don't write to the terminal while suspended (external editor active).
+    if (!isendwin()) {
+        doupdate();
+    }
     char* line = NULL;
     while (!line) {
         line = inp_readline();
@@ -338,7 +341,10 @@ inp_get_password(void)
     werase(inp_win);
     wmove(inp_win, 0, 0);
     _inp_win_update_virtual();
-    doupdate();
+    // Don't write to the terminal while suspended (external editor active).
+    if (!isendwin()) {
+        doupdate();
+    }
     char* password = NULL;
     get_password = TRUE;
     while (!password) {
@@ -459,7 +465,9 @@ _inp_write(char* line, int offset)
     _inp_win_handle_scroll();
 
     _inp_win_update_virtual();
-    doupdate();
+    if (!isendwin()) {
+        doupdate();
+    }
 }
 
 static int

src/ui/privwin.c

@@ -57,7 +57,7 @@ privwin_incoming_msg(ProfPrivateWin* privatewin, ProfMessage* message)
         privatewin->unread++;
 
         if (prefs_get_boolean(PREF_FLASH)) {
-            flash();
+            ui_flash();
         }
     }
 
@@ -65,7 +65,7 @@ privwin_incoming_msg(ProfPrivateWin* privatewin, ProfMessage* message)
     wins_add_quotes_ac(window, message->plain, TRUE);
 
     if (prefs_get_boolean(PREF_BEEP)) {
-        beep();
+        ui_beep();
     }
 
     if (notify) {

src/ui/ui.h

@@ -84,6 +84,8 @@ void ui_handle_recipient_error(const char* const recipient, const char* const er
 void ui_handle_error(const char* const err_msg);
 void ui_clear_win_title(void);
 void ui_goodbye_title(void);
+void ui_beep(void);
+void ui_flash(void);
 void ui_handle_room_configuration_form_error(const char* const roomjid, const char* const message);
 void ui_handle_room_config_submit_result(const char* const roomjid);
 void ui_handle_room_config_submit_result_error(const char* const roomjid, const char* const message);

tests/unittests/ui/stub_ui.c

@@ -1475,3 +1475,13 @@ ui_is_suspended(void)
 {
     return FALSE;
 }
+
+void
+ui_beep(void)
+{
+}
+
+void
+ui_flash(void)
+{
+}