fix(editor): prevent UI redraw conflicts during editor suspend/resume

Guard against re-entrant editor launches, abort editor on Ctrl-Z,
and centralize suspend-aware redraws through prof_doupdate() to prevent
terminal corruption when SIGTSTP is received while editor is active.

Removes SIGUSR1 editor escape in favor of standard pkill <editor> recovery.

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

@@ -54,6 +54,7 @@
 
 static int inp_size;
 static gboolean perform_resize = FALSE;
+static gboolean ui_suspended = FALSE;
 static GTimer* ui_idle_time;
 static WINDOW* main_scr;
 
@@ -63,6 +64,14 @@ static Display* display;
 
 static void _ui_draw_term_title(void);
 
+// Fail-safe gate: authoritative flag (doesn't depend on isendwin staying
+// TRUE), plus the regular endwin check for shutdown.
+static gboolean
+_ui_redraw_suspended(void)
+{
+    return ui_suspended || isendwin();
+}
+
 static void
 _ui_close(void)
 {
@@ -120,8 +129,7 @@ ui_sigwinch_handler(int sig)
 void
 ui_update(void)
 {
-    // UI is suspended
-    if (isendwin()) {
+    if (_ui_redraw_suspended()) {
         return;
     }
 
@@ -138,7 +146,7 @@ ui_update(void)
     title_bar_update_virtual();
     status_bar_draw();
     inp_put_back();
-    doupdate();
+    prof_doupdate();
 
     if (perform_resize) {
         perform_resize = FALSE;
@@ -180,21 +188,49 @@ void
 ui_suspend(void)
 {
     inp_suspend();
+    // Flush before flipping the flag (prof_doupdate skips while suspended).
+    prof_doupdate();
+    ui_suspended = TRUE;
     endwin();
 }
 
 void
 ui_resume(void)
 {
+    ui_suspended = FALSE;
+    clearok(stdscr, TRUE); // ncurses can't see vim's screen clobber
     refresh();
     inp_resume();
 }
 
+void
+ui_beep(void)
+{
+    if (!isendwin()) {
+        beep();
+    }
+}
+
+void
+ui_flash(void)
+{
+    if (!isendwin()) {
+        flash();
+    }
+}
+
+void
+prof_doupdate(void)
+{
+    if (!_ui_redraw_suspended()) {
+        doupdate();
+    }
+}
+
 void
 ui_resize(void)
 {
-    // UI is suspended
-    if (isendwin()) {
+    if (_ui_redraw_suspended()) {
         return;
     }
 
@@ -216,8 +252,7 @@ ui_resize(void)
 void
 ui_redraw(void)
 {
-    // UI is suspended
-    if (isendwin()) {
+    if (_ui_redraw_suspended()) {
         return;
     }
 

src/ui/inputwin.c

@@ -182,7 +182,11 @@ inp_readline(void)
 {
     // UI is suspended
     if (is_suspended || isendwin()) {
+        // Mirror the normal-path unlock so workers aren't starved
+        // for the whole editor session.
+        pthread_mutex_unlock(&lock);
         g_usleep(100000); // 100ms
+        pthread_mutex_lock(&lock);
         return NULL;
     }
 
@@ -311,11 +315,13 @@ inp_get_line(void)
     werase(inp_win);
     wmove(inp_win, 0, 0);
     _inp_win_update_virtual();
-    doupdate();
+    prof_doupdate();
     char* line = NULL;
     while (!line) {
         line = inp_readline();
         ui_update();
+        while (g_main_context_iteration(NULL, FALSE)) // non-blocking; bounded by ready sources
+            ;
     }
     status_bar_clear_prompt();
     return line;
@@ -338,12 +344,14 @@ inp_get_password(void)
     werase(inp_win);
     wmove(inp_win, 0, 0);
     _inp_win_update_virtual();
-    doupdate();
+    prof_doupdate();
     char* password = NULL;
     get_password = TRUE;
     while (!password) {
         password = inp_readline();
         ui_update();
+        while (g_main_context_iteration(NULL, FALSE)) // non-blocking; bounded by ready sources
+            ;
     }
     get_password = FALSE;
     status_bar_clear_prompt();
@@ -459,7 +467,7 @@ _inp_write(char* line, int offset)
     _inp_win_handle_scroll();
 
     _inp_win_update_virtual();
-    doupdate();
+    prof_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

@@ -43,6 +43,9 @@ void ui_load_colours(void);
 void ui_update(void);
 void ui_redraw(void);
 void ui_resize(void);
+// doupdate() wrapper that skips when the UI is suspended. Use this instead
+// of raw doupdate() to avoid the per-site whitelist class of bug.
+void prof_doupdate(void);
 void ui_focus_win(ProfWin* window);
 void ui_sigwinch_handler(int sig);
 void ui_handle_otr_error(const char* const barejid, const char* const message);
@@ -84,6 +87,8 @@ 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);