[HTML5] Make home path persistent in editor.

We used to only persist specific sub-folder of /home/web_user/ when
running the Web Editor. This resulted in bad UX about default project
creation path etc.
This PR makes the whole folder persistent, move the zip preloading to a
different folder (to avoid persisting it), and automatically prompt the
user to import it if present.

misc/dist/html/editor.html

@@ -327,7 +327,7 @@
  function startEditor(zip) {
 
  const INDETERMINATE_STATUS_STEP_MS = 100;
- const persistentPaths = ['/home/web_user/.config', '/home/web_user/.cache', '/home/web_user/projects'];
+ const persistentPaths = ['/home/web_user/'];
 
  var editorCanvas = document.getElementById('editor-canvas');
  var gameCanvas = document.getElementById('game-canvas');
@@ -498,11 +498,11 @@
  engine.setUnloadAfterInit(false); // Don't want to reload when starting game.
  engine.init('godot.tools').then(function() {
  if (zip) {
- engine.copyToFS("/home/web_user/preload.zip", zip);
+ engine.copyToFS("/tmp/preload.zip", zip);
  }
  try {
  // Avoid user creating project in the persistent root folder.
- engine.copyToFS("/home/web_user/projects/keep", new Uint8Array());
+ engine.copyToFS("/home/web_user/keep", new Uint8Array());
  } catch(e) {
  // File exists
  }

platform/javascript/javascript_main.cpp

@@ -87,6 +87,13 @@ extern EMSCRIPTEN_KEEPALIVE int godot_js_main(int argc, char *argv[]) {
  ResourceLoader::set_abort_on_missing_resources(false);
  Main::start();
  os->get_main_loop()->init();
+#ifdef TOOLS_ENABLED
+ if (Main::is_project_manager() && FileAccess::exists("/tmp/preload.zip")) {
+ PoolStringArray ps;
+ ps.push_back("/tmp/preload.zip");
+ os->get_main_loop()->emit_signal("files_dropped", ps, -1);
+ }
+#endif
  emscripten_set_main_loop(main_loop_callback, -1, false);
  // Immediately run the first iteration.
  // We are inside an animation frame, we want to immediately draw on the newly setup canvas.