feat(editor): add asynchronous external editor support

The synchronous `get_message_from_editor` blocked the main loop (`prof_run`) while launching an external editor like `vim`, halting network I/O in `session_process_events` and preventing incoming message reception.

Introduced `get_message_from_editor_async` for `cmd_editor` to run the editor asynchronously. It forks and execs the editor in a thread (`editor_thread`), suspending NCurses to free the terminal. The main loop skips `inp_readline` and `ui_update` via a new `background_mode` flag while the editor runs, allowing `session_process_events` to keep the connection alive.

On editor completion, `editor_process` (called per loop iteration) resumes NCurses with `ui_resize`, inserts the result into the readline buffer and clears `background_mode`.

Retained synchronous `get_message_from_editor` for ~20 existing code paths (e.g., `vcard_nickname`) to avoid breaking them.

Tested with `vim` and `nano`: confirms no rendering conflicts, messages received during editing, and seamless resume. Edge cases like editor crashes handled via error logging and seamless resume.

src/command/cmd_funcs.c

@@ -9527,16 +9527,7 @@ cmd_change_password(ProfWin* window, const char* const command, gchar** args)
 gboolean
 cmd_editor(ProfWin* window, const char* const command, gchar** args)
 {
-    auto_gchar gchar* message = NULL;
-
-    if (get_message_from_editor(NULL, &message)) {
-        return TRUE;
-    }
-
-    rl_insert_text(message);
-    ui_resize();
-    rl_point = rl_end;
-    rl_forced_update_display();
+    get_message_from_editor_async(NULL);
 
     return TRUE;
 }

src/common.h

@@ -171,6 +171,8 @@ typedef enum {
     RESOURCE_XA
 } resource_presence_t;
 
+extern gboolean background_mode;
+
 gboolean string_to_verbosity(const char* cmd, int* verbosity, gchar** err_msg);
 
 gboolean create_dir(const char* name);

src/profanity.c

@@ -59,6 +59,7 @@
 #include "config/tlscerts.h"
 #include "config/scripts.h"
 #include "command/cmd_defs.h"
+#include "tools/editor.h"
 #include "plugins/plugins.h"
 #include "event/client_events.h"
 #include "ui/ui.h"
@@ -93,6 +94,9 @@ static void _connect_default(const char* const account);
 pthread_mutex_t lock;
 static gboolean force_quit = FALSE;
 
+// main.c (prof_run section)
+gboolean background_mode = FALSE;
+
 void
 prof_run(gchar* log_level, gchar* account_name, gchar* config_file, gchar* log_file, gchar* theme_name, gchar** commands)
 {
@@ -118,42 +122,44 @@ prof_run(gchar* log_level, gchar* account_name, gchar* config_file, gchar* log_f
         log_stderr_handler();
         session_check_autoaway();
 
-        line = commands ? *commands : inp_readline();
-        if (commands && line && memcmp(line, "/sleep", 6) == 0) {
-            if (!g_timer_is_active(waittimer)) {
-                gchar* err_msg;
-                if (strtoi_range(line + 7, &waittime, 0, 300, &err_msg)) {
-                    g_timer_start(waittimer);
-                    /* Increase the minimal runtime by the waiting time
-                     * so we can be sure there's runtime left after executing
-                     * the last command.
-                     */
-                    min_runtime += waittime;
-                } else {
-                    log_error(err_msg);
-                    g_free(err_msg);
-                    commands = NULL;
+        if (!background_mode) {
+            line = commands ? *commands : inp_readline();
+            if (commands && line && memcmp(line, "/sleep", 6) == 0) {
+                if (!g_timer_is_active(waittimer)) {
+                    gchar* err_msg;
+                    if (strtoi_range(line + 7, &waittime, 0, 300, &err_msg)) {
+                        g_timer_start(waittimer);
+                        /* Increase the minimal runtime by the waiting time
+                         * so we can be sure there's runtime left after executing
+                         * the last command.
+                         */
+                        min_runtime += waittime;
+                    } else {
+                        log_error(err_msg);
+                        g_free(err_msg);
+                        commands = NULL;
+                    }
+                } else if (g_timer_elapsed(waittimer, NULL) >= waittime) {
+                    g_timer_stop(waittimer);
+                    commands++;
+                    if (!(*commands))
+                        commands = NULL;
+                }
+                cont = TRUE;
+            } else if (line) {
+                ProfWin* window = wins_get_current();
+                cont = cmd_process_input(window, line);
+                if (commands) {
+                    commands++;
+                    if (!(*commands))
+                        commands = NULL;
+                } else {
+                    free(line);
+                    line = NULL;
                 }
-            } else if (g_timer_elapsed(waittimer, NULL) >= waittime) {
-                g_timer_stop(waittimer);
-                commands++;
-                if (!(*commands))
-                    commands = NULL;
-            }
-            cont = TRUE;
-        } else if (line) {
-            ProfWin* window = wins_get_current();
-            cont = cmd_process_input(window, line);
-            if (commands) {
-                commands++;
-                if (!(*commands))
-                    commands = NULL;
             } else {
-                free(line);
-                line = NULL;
+                cont = TRUE;
             }
-        } else {
-            cont = TRUE;
         }
 
 #ifdef HAVE_LIBOTR
@@ -163,7 +169,12 @@ prof_run(gchar* log_level, gchar* account_name, gchar* config_file, gchar* log_f
         notify_remind();
         session_process_events();
         iq_autoping_check();
-        ui_update();
+
+        editor_process(wins_get_current());
+
+        if (!background_mode) {
+            ui_update();
+        }
 #ifdef HAVE_GTK
         tray_update();
 #endif

src/tools/editor.c

@@ -38,15 +38,200 @@
 #include <fcntl.h>
 #include <glib.h>
 #include <errno.h>
+#include <stdio.h> // necessary for readline
+#include <readline/readline.h>
 #include <sys/wait.h>
 #include <unistd.h>
+#include <pthread.h>
 
 #include "config/files.h"
 #include "config/preferences.h"
+#include "editor.h"
 #include "log.h"
 #include "common.h"
+#include "ncurses.h"
+#include "ui/ui.h"
 #include "xmpp/xmpp.h"
 
+EditorTask editor_task = { 0, FALSE, NULL, NULL, PTHREAD_MUTEX_INITIALIZER, 0, NULL, NULL };
+
+void*
+editor_thread(void* arg)
+{
+    EditorTask* task = (EditorTask*)arg;
+    auto_gcharv gchar** argv = g_strsplit(task->editor_cmd, " ", 0);
+
+    pid_t pid = fork();
+    if (pid == 0) {
+        execvp(argv[0], argv);
+        log_error("[Editor] Failed to exec %s", argv[0]);
+        _exit(EXIT_FAILURE);
+    }
+
+    pthread_mutex_lock(&task->mutex);
+    if (pid > 0) {
+        task->pid = pid;
+        int status;
+        // Unlock mutex to avoid deadlock on the main loop
+        pthread_mutex_unlock(&task->mutex);
+        waitpid(pid, &status, 0);
+        pthread_mutex_lock(&task->mutex);
+
+        gsize length;
+        if (!g_file_get_contents(task->filename, &task->result, &length, &task->error)) {
+            log_error("[Editor] could not read from %s: %s", task->filename,
+                      task->error ? task->error->message : "No GLib error given");
+            task->result = g_strdup(""); // Ensure valid result
+        } else {
+            g_strchomp(task->result);
+            if (remove(task->filename) != 0) {
+                log_error("[Editor] error during file deletion of %s", task->filename);
+            } else {
+                log_debug("[Editor] deleted file: %s", task->filename);
+            }
+        }
+        if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+            task->error = g_error_new(G_FILE_ERROR, G_FILE_ERROR_FAILED,
+                                      "Editor process failed with status %d", WEXITSTATUS(status));
+        }
+    } else {
+        task->error = g_error_new(G_FILE_ERROR, G_FILE_ERROR_FAILED, "Fork failed: %s", strerror(errno));
+        task->result = g_strdup(""); // Ensure valid result
+    }
+
+    task->active = FALSE;
+    pthread_mutex_unlock(&task->mutex);
+
+    return NULL;
+}
+
+// Returns true if an error occurred
+gboolean
+get_message_from_editor_async(gchar* message)
+{
+    // Check if editor is already running
+    pthread_mutex_lock(&editor_task.mutex);
+    if (editor_task.active) {
+        pthread_mutex_unlock(&editor_task.mutex);
+        log_error("[Editor] Editor already running");
+        return TRUE;
+    }
+    pthread_mutex_unlock(&editor_task.mutex);
+
+    // Create temporary file
+    auto_gchar gchar* filename = NULL;
+    GError* glib_error = NULL;
+    const char* jid = connection_get_barejid();
+    if (jid) {
+        filename = files_file_in_account_data_path(DIR_EDITOR, jid, "compose.md");
+    } else {
+        log_debug("[Editor] could not get JID");
+        auto_gchar gchar* data_dir = files_get_data_path(DIR_EDITOR);
+        if (!create_dir(data_dir)) {
+            log_error("[Editor] could not create directory %s", data_dir);
+            return TRUE;
+        }
+        filename = g_strdup_printf("%s/compose.md", data_dir);
+    }
+    if (!filename) {
+        log_error("[Editor] something went wrong while creating compose file");
+        return TRUE;
+    }
+
+    // Write message to file
+    gsize messagelen = message ? strlen(message) : 0;
+    if (!g_file_set_contents(filename, message ? message : "", messagelen, &glib_error)) {
+        log_error("[Editor] could not write to %s: %s", filename,
+                  glib_error ? glib_error->message : "No GLib error given");
+        if (glib_error) {
+            g_error_free(glib_error);
+        }
+        return TRUE;
+    }
+
+    // Prepare editor command
+    auto_gchar gchar* editor = prefs_get_string(PREF_COMPOSE_EDITOR);
+    auto_gchar gchar* editor_with_filename = g_strdup_printf("%s %s", editor, filename);
+
+    // Suspend NCurses
+    def_prog_mode();
+    endwin();
+
+    // Initialize thread task
+    pthread_mutex_lock(&editor_task.mutex);
+    editor_task.active = TRUE;
+    editor_task.result = NULL;
+    editor_task.error = NULL;
+    g_free(editor_task.filename);
+    g_free(editor_task.editor_cmd);
+    editor_task.filename = g_strdup(filename);
+    editor_task.editor_cmd = g_strdup(editor_with_filename);
+    pthread_mutex_unlock(&editor_task.mutex);
+
+    // Set background mode
+    background_mode = TRUE;
+    log_debug("[Editor] Entering background mode");
+
+    // Start editor thread
+    if (pthread_create(&editor_task.thread, NULL, editor_thread, &editor_task) != 0) {
+        pthread_mutex_lock(&editor_task.mutex);
+        editor_task.active = FALSE;
+        editor_task.error = g_error_new(G_FILE_ERROR, G_FILE_ERROR_FAILED,
+                                        "Failed to create editor thread: %s", strerror(errno));
+        g_free(editor_task.filename);
+        g_free(editor_task.editor_cmd);
+        editor_task.filename = NULL;
+        editor_task.editor_cmd = NULL;
+        pthread_mutex_unlock(&editor_task.mutex);
+        background_mode = FALSE;
+        log_debug("[Editor] Exiting background mode");
+        reset_prog_mode();
+        doupdate();
+        log_error("[Editor] Failed to create editor thread");
+        return TRUE;
+    }
+
+    return FALSE;
+}
+
+void
+editor_process(ProfWin* window)
+{
+    pthread_mutex_lock(&editor_task.mutex);
+    if (editor_task.active) {
+        pthread_mutex_unlock(&editor_task.mutex);
+        return;
+    }
+    if (!editor_task.result) {
+        pthread_mutex_unlock(&editor_task.mutex);
+        return;
+    }
+
+    g_strchomp(editor_task.result);
+    rl_replace_line(editor_task.result, 0);
+    rl_point = rl_end;
+    rl_forced_update_display();
+    reset_prog_mode();
+    doupdate();
+    ui_resize();
+    g_free(editor_task.result);
+    g_free(editor_task.filename);
+    g_free(editor_task.editor_cmd);
+    editor_task.result = NULL;
+    editor_task.filename = NULL;
+    editor_task.editor_cmd = NULL;
+    if (editor_task.error) {
+        log_error("[Editor] %s", editor_task.error->message);
+        g_error_free(editor_task.error);
+        editor_task.error = NULL;
+    }
+    pthread_mutex_unlock(&editor_task.mutex);
+    background_mode = FALSE;
+    log_debug("[Editor] Exiting background mode");
+}
+
+// Deprecated synchronous editor call. Returns a message as returned_message.
+// Please avoid using it, since it blocks execution of the message handling and other important functionality until the editor is closed.
 // Returns true if an error occurred
 gboolean
 get_message_from_editor(gchar* message, gchar** returned_message)

src/tools/editor.h

@@ -37,8 +37,24 @@
 #ifndef TOOLS_EDITOR_H
 #define TOOLS_EDITOR_H
 
+#include "ui/win_types.h"
 #include <glib.h>
+typedef struct
+{
+    pid_t pid;             // Editor process PID
+    gboolean active;       // Thread running
+    gchar* result;         // Edited message
+    GError* error;         // Error if any
+    pthread_mutex_t mutex; // Protect access
+    pthread_t thread;      // Editor thread
+    gchar* filename;       // Temporary file path
+    gchar* editor_cmd;     // Editor command with filename
+} EditorTask;
+
+extern EditorTask editor_task;
 
 gboolean get_message_from_editor(gchar* message, gchar** returned_message);
+gboolean get_message_from_editor_async(gchar* message);
+void editor_process(ProfWin* window);
 
 #endif

src/ui/inputwin.c

@@ -974,14 +974,7 @@ _inp_rl_send_to_editor(int count, int key)
 
     auto_gchar gchar* message = NULL;
 
-    if (get_message_from_editor(rl_line_buffer, &message)) {
-        return 0;
-    }
-
-    rl_replace_line(message, 0);
-    ui_resize();
-    rl_point = rl_end;
-    rl_forced_update_display();
+    get_message_from_editor_async(rl_line_buffer);
 
     return 0;
 }