fix(editor): Ctrl-Z aborts editor and returns to profanity

Replaces the SIGTSTP=SIG_IGN inheritance approach (was commit 8) with a
detect-and-abort design that matches user expectation: Ctrl-Z inside
the editor brings you back to profanity instead of leaving the session
suspended.

- src/tools/editor.c: SIGTSTP reset back to SIG_DFL in the child so
  vim's :stop / Ctrl-Z actually stop the editor (revert previous
  SIG_IGN inheritance).
- src/tools/editor.c: new editor_check_stopped() — non-reaping waitpid
  poll for WIFSTOPPED. Lets prof_run detect Ctrl-Z / :stop / gdb-attach
  on the editor child.
- src/tools/editor.c: editor_emergency_kill() now sends SIGCONT before
  SIGTERM so the abort works on a STOPPED child too.
- src/tools/editor.c: _editor_exit_cb handles WIFSIGNALED cleanly with
  "Editor session cancelled." instead of printing garbage via
  WEXITSTATUS on a signaled child.
- src/profanity.c: SIGTSTP / SIGCONT signal handlers set flags consumed
  by the main loop. Editor STOPPED -> editor_emergency_kill (returns to
  the chat with the pre-alt+c readline buffer intact). Plain Ctrl-Z
  with no editor -> mutt-style drop the process group to the shell.
  SIGCONT -> refresh curses with clearok + ui_resize. While editor is
  active, swallow suspend_requested (race: vim's kill(0,SIGTSTP) beats
  waitpid seeing STOPPED — next poll catches it).
- src/tools/editor.h: declare editor_check_stopped and editor_is_active.

Verbose comment blocks across the branch tightened to one to two lines.

src/profanity.c

@@ -20,6 +20,7 @@
 #include <string.h>
 
 #include <glib.h>
+#include <glib-unix.h>
 
 #include "profanity.h"
 #include "common.h"
@@ -70,6 +71,12 @@ static void _connect_default(const char* const account);
 pthread_mutex_t lock;
 static gboolean force_quit = FALSE;
 
+// Signal-driven flags consumed by the main loop. SIGTSTP and a STOPPED editor
+// child → drop the process group to the shell (mutt-style). SIGCONT →
+// refresh curses on return.
+static volatile sig_atomic_t suspend_requested = FALSE;
+static volatile sig_atomic_t cont_requested = FALSE;
+
 void
 prof_run(gchar* log_level, gchar* account_name, gchar* config_file, gchar* log_file, gchar* theme_name, gchar** commands)
 {
@@ -93,6 +100,36 @@ prof_run(gchar* log_level, gchar* account_name, gchar* config_file, gchar* log_f
     int waittime = 0;
     while (cont && !force_quit) {
         log_stderr_handler();
+
+        // Resume from fg after SIGSTOP. Vim handles its own refresh.
+        if (cont_requested) {
+            cont_requested = FALSE;
+            if (!editor_is_active()) {
+                clearok(stdscr, TRUE);
+                ui_resize();
+            }
+        }
+
+        // Editor STOPPED → abort. Plain Ctrl-Z → drop to shell. While editor
+        // is active, swallow suspend_requested (race: vim's kill(0,SIGTSTP)
+        // beats waitpid seeing STOPPED) — next poll catches it.
+        if (editor_check_stopped()) {
+            log_info("[Editor] stopped; aborting back to profanity");
+            suspend_requested = FALSE;
+            editor_emergency_kill();
+        } else if (suspend_requested) {
+            suspend_requested = FALSE;
+            if (editor_is_active()) {
+                log_info("[Editor] SIGTSTP from vim group; deferring to next poll");
+            } else {
+                log_info("[Suspend] dropping to shell");
+                if (!isendwin()) {
+                    endwin();
+                }
+                kill(0, SIGSTOP);
+            }
+        }
+
         session_check_autoaway();
 
         line = commands ? *commands : inp_readline();
@@ -182,6 +219,27 @@ sigterm_handler(int sig)
     force_quit = TRUE;
 }
 
+// SIGUSR1 escape for an alive-but-stuck editor (WUNTRACED can't catch it).
+// Dispatched in the main loop. Trigger: `pkill -USR1 profanity`.
+static gboolean
+_emergency_resume_handler(gpointer data)
+{
+    editor_emergency_kill();
+    return G_SOURCE_CONTINUE;
+}
+
+static void
+sigtstp_handler(int sig)
+{
+    suspend_requested = TRUE;
+}
+
+static void
+sigcont_handler(int sig)
+{
+    cont_requested = TRUE;
+}
+
 static void
 _init(char* log_level, char* config_file, char* log_file, char* theme_name)
 {
@@ -189,10 +247,12 @@ _init(char* log_level, char* config_file, char* log_file, char* theme_name)
     // ignore SIGPIPE
     signal(SIGPIPE, SIG_IGN);
     signal(SIGINT, SIG_IGN);
-    signal(SIGTSTP, SIG_IGN);
+    signal(SIGTSTP, sigtstp_handler);
+    signal(SIGCONT, sigcont_handler);
     signal(SIGWINCH, ui_sigwinch_handler);
     signal(SIGTERM, sigterm_handler);
     signal(SIGHUP, sigterm_handler);
+    g_unix_signal_add(SIGUSR1, _emergency_resume_handler, NULL);
     if (pthread_mutex_init(&lock, NULL) != 0) {
         log_error("Mutex init failed");
         exit(1);

src/tools/editor.c

@@ -32,19 +32,16 @@ typedef struct EditorContext
     void* user_data;
 } EditorContext;
 
-// Set TRUE for the lifetime of an editor session (from launch_editor up to
-// _editor_exit_cb / fork-error cleanup). The async editor model lost the old
-// editor_task.active check from the pthread implementation; without this
-// guard a second launch_editor (e.g. via a plugin dispatched through
-// g_main_context_iteration) would call ui_suspend again and fork a second
-// editor that fights the first one for the terminal, then prematurely
-// ui_resume when either exits.
+// Re-entrancy guard (lost in the async-editor rewrite). Prevents a plugin
+// from spawning a second editor that would fight the first for the terminal.
 static gboolean editor_active = FALSE;
+static pid_t editor_pid = 0;
 
 static void
 _editor_exit_cb(GPid pid, gint status, gpointer data)
 {
     editor_active = FALSE;
+    editor_pid = 0;
 
     EditorContext* ctx = data;
     gchar* contents = NULL;
@@ -63,8 +60,10 @@ _editor_exit_cb(GPid pid, gint status, gpointer data)
             cons_show_error("Could not read edited content: %s", error->message);
             g_error_free(error);
         }
-    } else {
-        cons_show_error("Editor exited with error status %d", WEXITSTATUS(status));
+    } else if (WIFEXITED(status)) {
+        cons_show_error("Editor exited with status %d", WEXITSTATUS(status));
+    } else if (WIFSIGNALED(status)) {
+        cons_show("Editor session cancelled.");
     }
 
     if (remove(ctx->filename) != 0) {
@@ -157,7 +156,8 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
     } else if (pid == 0) {
         // Child process: Inherits TTY from parent
 
-        // Reset signal handlers that profanity sets so the editor doesn't inherit them
+        // SIGTSTP=SIG_DFL lets vim's :stop / Ctrl-Z work; profanity catches
+        // the STOPPED state via editor_check_stopped() and drops to the shell.
         signal(SIGINT, SIG_DFL);
         signal(SIGTSTP, SIG_DFL);
         signal(SIGPIPE, SIG_DFL);
@@ -169,7 +169,39 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
     }
 
     // Parent process: Watch the child asynchronously
+    editor_pid = pid;
     g_child_watch_add((GPid)pid, _editor_exit_cb, ctx);
     g_strfreev(editor_argv);
     return FALSE;
 }
+
+void
+editor_emergency_kill(void)
+{
+    if (!editor_active || editor_pid <= 0) {
+        return;
+    }
+    log_warning("[Editor] aborting editor pid %d", editor_pid);
+    kill(editor_pid, SIGCONT);  // wake if STOPPED; no-op otherwise
+    kill(editor_pid, SIGTERM);
+    // _editor_exit_cb will restore the UI when the child reaps.
+}
+
+gboolean
+editor_is_active(void)
+{
+    return editor_active;
+}
+
+gboolean
+editor_check_stopped(void)
+{
+    // Poll for STOPPED without reaping (g_child_watch handles exit via its
+    // own WNOHANG). Lets prof_run drop the group to the shell on Ctrl-Z.
+    if (!editor_active || editor_pid <= 0) {
+        return FALSE;
+    }
+    int status;
+    pid_t r = waitpid(editor_pid, &status, WNOHANG | WUNTRACED);
+    return (r == editor_pid && WIFSTOPPED(status));
+}

src/tools/editor.h

@@ -16,4 +16,15 @@
 
 gboolean launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* data), void* user_data);
 
+// SIGUSR1 escape: SIGTERM the editor child. Use when WUNTRACED can't catch
+// it (alive but stuck). Wired in profanity.c.
+void editor_emergency_kill(void);
+
+// TRUE if editor child is STOPPED (Ctrl-Z / :stop / gdb-attach). Does not
+// reap; g_child_watch keeps handling exit.
+gboolean editor_check_stopped(void);
+
+// Editor-session flag accessor. Used by prof_run on SIGCONT resume.
+gboolean editor_is_active(void);
+
 #endif

src/ui/core.c

@@ -64,10 +64,8 @@ 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). The flag is authoritative and does not rely
-// on isendwin() staying TRUE, which a stray doupdate() during the session could
-// otherwise clear.
+// 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)
 {

src/ui/inputwin.c

@@ -182,10 +182,8 @@ inp_readline(void)
 {
     // UI is suspended
     if (is_suspended || isendwin()) {
-        // Mirror the normal-path unlock/sleep/lock so worker threads
-        // (http_upload / http_download / ai_client) can acquire `lock`
-        // during the editor session — otherwise the main thread holds
-        // it continuously and every in-flight transfer freezes.
+        // 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);
@@ -322,8 +320,8 @@ inp_get_line(void)
     while (!line) {
         line = inp_readline();
         ui_update();
-        // Let GLib sources (notably the editor child watch) dispatch so
-        // ui_resume can run if the prompt was raised mid-editor-session.
+        // Let the editor child watch dispatch — otherwise a prompt raised
+        // mid-editor-session deadlocks here.
         while (g_main_context_iteration(NULL, FALSE))
             ;
     }
@@ -354,8 +352,8 @@ inp_get_password(void)
     while (!password) {
         password = inp_readline();
         ui_update();
-        // Let GLib sources (notably the editor child watch) dispatch so
-        // ui_resume can run if the prompt was raised mid-editor-session.
+        // Let the editor child watch dispatch — otherwise a prompt raised
+        // mid-editor-session deadlocks here.
         while (g_main_context_iteration(NULL, FALSE))
             ;
     }

src/ui/ui.h

@@ -43,9 +43,8 @@ void ui_load_colours(void);
 void ui_update(void);
 void ui_redraw(void);
 void ui_resize(void);
-// Centralised physical-paint primitive: flushes the virtual screen unless the
-// UI is suspended (external editor active) or the screen has been closed. Use
-// this instead of raw doupdate() in any path reachable while suspended.
+// 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);