[HTML5] Drag and drop zip in project manager.

With a very nice hack, a new hidden configuration option that delays
dropped files removal at exit.

This still leaks while the project manager is running, but will clear
memory as soon as it exits or load something.
(reminder, dropped files are reguarly removed after the signal is
emitted specifically to avoid leaks, but I prefer hacking the HTML5
config then the project manager).

3 files changed, 48 insertions, 26 deletions

diff --git a/platform/javascript/js/engine/config.js b/platform/javascript/js/engine/config.js
index 25d71d0905..6072782875 100644
--- a/platform/javascript/js/engine/config.js
+++ b/platform/javascript/js/engine/config.js
@@ -105,6 +105,11 @@ const InternalConfig = function (initConfig) { // eslint-disable-line no-unused-
 		persistentPaths: ['/userfs'],
 		/**
 		 * @ignore
+		 * @type {boolean}
+		 */
+		persistentDrops: false,
+		/**
+		 * @ignore
 		 * @type {Array.<string>}
 		 */
 		gdnativeLibs: [],
@@ -231,6 +236,7 @@ const InternalConfig = function (initConfig) { // eslint-disable-line no-unused-
 		this.locale = parse('locale', this.locale);
 		this.canvasResizePolicy = parse('canvasResizePolicy', this.canvasResizePolicy);
 		this.persistentPaths = parse('persistentPaths', this.persistentPaths);
+		this.persistentDrops = parse('persistentDrops', this.persistentDrops);
 		this.experimentalVK = parse('experimentalVK', this.experimentalVK);
 		this.gdnativeLibs = parse('gdnativeLibs', this.gdnativeLibs);
 		this.fileSizes = parse('fileSizes', this.fileSizes);
@@ -316,6 +322,7 @@ const InternalConfig = function (initConfig) { // eslint-disable-line no-unused-
 			'canvas': this.canvas,
 			'canvasResizePolicy': this.canvasResizePolicy,
 			'locale': locale,
+			'persistentDrops': this.persistentDrops,
 			'virtualKeyboard': this.experimentalVK,
 			'onExecute': this.onExecute,
 			'onExit': function (p_code) {
diff --git a/platform/javascript/js/libs/library_godot_display.js b/platform/javascript/js/libs/library_godot_display.js
index b36220ac9e..99aa4793d9 100644
--- a/platform/javascript/js/libs/library_godot_display.js
+++ b/platform/javascript/js/libs/library_godot_display.js
@@ -192,33 +192,45 @@ const GodotDisplayDragDrop = {
 				GodotDisplayDragDrop.promises = [];
 				GodotDisplayDragDrop.pending_files = [];
 				callback(drops);
-				const dirs = [DROP.substr(0, DROP.length - 1)];
-				// Remove temporary files
-				files.forEach(function (file) {
-					FS.unlink(file);
-					let dir = file.replace(DROP, '');
-					let idx = dir.lastIndexOf('/');
-					while (idx > 0) {
-						dir = dir.substr(0, idx);
-						if (dirs.indexOf(DROP + dir) === -1) {
-							dirs.push(DROP + dir);
-						}
-						idx = dir.lastIndexOf('/');
-					}
-				});
-				// Remove dirs.
-				dirs.sort(function (a, b) {
-					const al = (a.match(/\//g) || []).length;
-					const bl = (b.match(/\//g) || []).length;
-					if (al > bl) {
-						return -1;
-					} else if (al < bl) {
-						return 1;
+				if (GodotConfig.persistent_drops) {
+					// Delay removal at exit.
+					GodotOS.atexit(function (resolve, reject) {
+						GodotDisplayDragDrop.remove_drop(files, DROP);
+						resolve();
+					});
+				} else {
+					GodotDisplayDragDrop.remove_drop(files, DROP);
+				}
+			});
+		},
+
+		remove_drop: function (files, drop_path) {
+			const dirs = [drop_path.substr(0, drop_path.length - 1)];
+			// Remove temporary files
+			files.forEach(function (file) {
+				FS.unlink(file);
+				let dir = file.replace(drop_path, '');
+				let idx = dir.lastIndexOf('/');
+				while (idx > 0) {
+					dir = dir.substr(0, idx);
+					if (dirs.indexOf(drop_path + dir) === -1) {
+						dirs.push(drop_path + dir);
 					}
-					return 0;
-				}).forEach(function (dir) {
-					FS.rmdir(dir);
-				});
+					idx = dir.lastIndexOf('/');
+				}
+			});
+			// Remove dirs.
+			dirs.sort(function (a, b) {
+				const al = (a.match(/\//g) || []).length;
+				const bl = (b.match(/\//g) || []).length;
+				if (al > bl) {
+					return -1;
+				} else if (al < bl) {
+					return 1;
+				}
+				return 0;
+			}).forEach(function (dir) {
+				FS.rmdir(dir);
 			});
 		},
 
diff --git a/platform/javascript/js/libs/library_godot_os.js b/platform/javascript/js/libs/library_godot_os.js
index 775a822d88..1d9f889bce 100644
--- a/platform/javascript/js/libs/library_godot_os.js
+++ b/platform/javascript/js/libs/library_godot_os.js
@@ -60,6 +60,7 @@ const GodotConfig = {
 		locale: 'en',
 		canvas_resize_policy: 2, // Adaptive
 		virtual_keyboard: false,
+		persistent_drops: false,
 		on_execute: null,
 		on_exit: null,
 
@@ -68,6 +69,7 @@ const GodotConfig = {
 			GodotConfig.canvas = p_opts['canvas'];
 			GodotConfig.locale = p_opts['locale'] || GodotConfig.locale;
 			GodotConfig.virtual_keyboard = p_opts['virtualKeyboard'];
+			GodotConfig.persistent_drops = !!p_opts['persistentDrops'];
 			GodotConfig.on_execute = p_opts['onExecute'];
 			GodotConfig.on_exit = p_opts['onExit'];
 		},
@@ -80,6 +82,7 @@ const GodotConfig = {
 			GodotConfig.locale = 'en';
 			GodotConfig.canvas_resize_policy = 2;
 			GodotConfig.virtual_keyboard = false;
+			GodotConfig.persistent_drops = false;
 			GodotConfig.on_execute = null;
 			GodotConfig.on_exit = null;
 		},