feat: make :restart work for remote UI (#34354)

src/nvim/ui_client.c

@@ -7,12 +7,9 @@
 
 #include "nvim/api/keysets_defs.h"
 #include "nvim/api/private/defs.h"
-#include "nvim/api/private/dispatch.h"
 #include "nvim/api/private/helpers.h"
 #include "nvim/channel.h"
 #include "nvim/channel_defs.h"
-#include "nvim/eval.h"
-#include "nvim/eval/typval.h"
 #include "nvim/eval/typval_defs.h"
 #include "nvim/event/multiqueue.h"
 #include "nvim/globals.h"
@@ -25,7 +22,6 @@
 #include "nvim/msgpack_rpc/channel.h"
 #include "nvim/msgpack_rpc/channel_defs.h"
 #include "nvim/os/os.h"
-#include "nvim/os/os_defs.h"
 #include "nvim/profile.h"
 #include "nvim/tui/tui.h"
 #include "nvim/tui/tui_defs.h"
@@ -51,14 +47,13 @@ static bool ui_client_is_remote = false;
 #endif
 // uncrustify:on
 
-uint64_t ui_client_start_server(int argc, char **argv)
+uint64_t ui_client_start_server(const char *exepath, size_t argc, char **argv)
 {
-  varnumber_T exit_status;
-  char **args = xmalloc(((size_t)(2 + argc)) * sizeof(char *));
+  char **args = xmalloc((2 + argc) * sizeof(char *));
   int args_idx = 0;
   args[args_idx++] = xstrdup(argv[0]);
   args[args_idx++] = xstrdup("--embed");
-  for (int i = 1; i < argc; i++) {
+  for (size_t i = 1; i < argc; i++) {
     args[args_idx++] = xstrdup(argv[i]);
   }
   args[args_idx++] = NULL;
@@ -72,7 +67,8 @@ uint64_t ui_client_start_server(int argc, char **argv)
 #else
   bool detach = true;
 #endif
-  Channel *channel = channel_job_start(args, get_vim_var_str(VV_PROGPATH),
+  varnumber_T exit_status;
+  Channel *channel = channel_job_start(args, exepath,
                                        CALLBACK_READER_INIT, on_err, CALLBACK_NONE,
                                        false, true, true, detach, kChannelStdinPipe,
                                        NULL, 0, 0, NULL, &exit_status);
@@ -287,57 +283,69 @@ void ui_client_event_raw_line(GridLineEvent *g)
                (const schar_T *)grid_line_buf_char, grid_line_buf_attr);
 }
 
-/// Restarts the embedded server without killing the UI.
+/// When a "restart" UI event is received, its arguments are saved here when
+/// waiting for the server to exit.
+static Array restart_args = ARRAY_DICT_INIT;
+static bool restart_pending = false;
+
 void ui_client_event_restart(Array args)
 {
-  // 1. Client-side server detach.
-  ui_client_detach();
+  // NB: don't send nvim_ui_detach to server, as it may have already exited.
+  // ui_client_detach();
 
-  // 2. Close ui client channel (auto kills the `nvim --embed` server due to self-exit).
-  const char *error;
-  bool success = channel_close(ui_client_channel_id, kChannelPartAll, &error);
-  if (!success) {
-    ELOG("%s", error);
+  // Save the arguments for ui_client_may_restart_server() later.
+  api_free_array(restart_args);
+  restart_args = copy_array(args, NULL);
+  restart_pending = true;
+}
+
+/// Called when the current server has exited.
+void ui_client_may_restart_server(void)
+{
+  if (!restart_pending) {
     return;
   }
+  restart_pending = false;
 
-  // 3. Get v:argv.
-  typval_T *tv = get_vim_var_tv(VV_ARGV);
-  if (tv->v_type != VAR_LIST || tv->vval.v_list == NULL) {
-    ELOG("failed to get vim var typval");
-    return;
+  size_t argc;
+  char **argv = NULL;
+  if (restart_args.size < 2
+      || restart_args.items[0].type != kObjectTypeString
+      || restart_args.items[1].type != kObjectTypeArray
+      || (argc = restart_args.items[1].data.array.size) < 1) {
+    ELOG("Error handling ui event 'restart'");
+    goto cleanup;
   }
-  list_T *l = tv->vval.v_list;
-  int argc = tv_list_len(l);
 
-  // Assert to be positive for safe conversion to size_t.
-  assert(argc > 0);
-
-  char **argv = xmalloc(sizeof(char *) * ((size_t)argc + 1));
-  listitem_T *li = tv_list_first(l);
-  for (int i = 0; i < argc && li != NULL; i++, li = TV_LIST_ITEM_NEXT(l, li)) {
-    if (TV_LIST_ITEM_TV(li)->v_type == VAR_STRING && TV_LIST_ITEM_TV(li)->vval.v_string != NULL) {
-      argv[i] = TV_LIST_ITEM_TV(li)->vval.v_string;
-    } else {
+  // 1. Get executable path and command-line arguments.
+  const char *exepath = restart_args.items[0].data.string.data;
+  argv = xcalloc(argc + 1, sizeof(char *));
+  for (size_t i = 0; i < argc; i++) {
+    if (restart_args.items[1].data.array.items[i].type == kObjectTypeString) {
+      argv[i] = restart_args.items[1].data.array.items[i].data.string.data;
+    }
+    if (argv[i] == NULL) {
       argv[i] = "";
     }
   }
-  argv[argc] = NULL;
 
-  // 4. Start a new `nvim --embed` server.
-  uint64_t rv = ui_client_start_server(argc, argv);
+  // 2. Start a new `nvim --embed` server.
+  uint64_t rv = ui_client_start_server(exepath, argc, argv);
   if (!rv) {
     ELOG("failed to start nvim server");
     goto cleanup;
   }
 
-  // 5. Client-side server re-attach.
+  // 3. Client-side server re-attach.
   ui_client_channel_id = rv;
+  ui_client_is_remote = false;
   ui_client_attach(tui_width, tui_height, tui_term, tui_rgb);
 
   ILOG("restarted server id=%" PRId64, rv);
 cleanup:
   xfree(argv);
+  api_free_array(restart_args);
+  restart_args = (Array)ARRAY_DICT_INIT;
 }
 
 #ifdef EXITFREE