From 029d81b67582a7d8e7df19b2d65c0e2a307f998f Mon Sep 17 00:00:00 2001
From: Adam Sardo <adamsardo98@gmail.com>
Date: Sat, 9 May 2026 21:59:25 +1000
Subject: [PATCH 1/3] Fix resource paths with hash characters

---
 GDJS/Runtime/ResourceLoader.ts          | 15 +++++++++++++++
 newIDE/app/src/ResourcesLoader/index.js | 11 +++++++----
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/GDJS/Runtime/ResourceLoader.ts b/GDJS/Runtime/ResourceLoader.ts
index 66d8ed777492..edab754bc0c8 100644
--- a/GDJS/Runtime/ResourceLoader.ts
+++ b/GDJS/Runtime/ResourceLoader.ts
@@ -29,6 +29,19 @@ namespace gdjs {
     );
   };
 
+  const encodeLocalResourceUrl = (url: string): string => {
+    if (
+      url.startsWith('http://') ||
+      url.startsWith('https://') ||
+      url.startsWith('data:') ||
+      url.startsWith('blob:')
+    ) {
+      return url;
+    }
+
+    return encodeURI(url).replace(/#/g, '%23');
+  };
+
   /**
    * A task of pre-loading resources used by a scene.
    *
@@ -617,6 +630,8 @@ namespace gdjs {
      * the resource (this can be for example a token needed to access the resource).
      */
     getFullUrl(url: string) {
+      url = encodeLocalResourceUrl(url);
+
       if (this._runtimeGame.isInGameEdition()) {
         // Avoid adding cache burst to URLs which are assumed to be immutable files,
         // to avoid costly useless requests each time the game is hot-reloaded.
diff --git a/newIDE/app/src/ResourcesLoader/index.js b/newIDE/app/src/ResourcesLoader/index.js
index 43f2d79d6d80..5a4df16ac746 100644
--- a/newIDE/app/src/ResourcesLoader/index.js
+++ b/newIDE/app/src/ResourcesLoader/index.js
@@ -3,6 +3,7 @@ import { addGDevelopResourceTokenIfRequired } from '../Utils/CrossOrigin';
 import optionalRequire from '../Utils/OptionalRequire';
 const electron = optionalRequire('electron');
 const path = optionalRequire('path');
+const nodeUrl = optionalRequire('url');
 
 class UrlsCache {
   projectCache: { [number]: { [string]: string } } = {};
@@ -132,15 +133,17 @@ export default class ResourcesLoader {
       // Support local filesystem with Electron
       const file = project.getProjectFile();
       const projectPath = path.dirname(file);
-      const resourceAbsolutePath = path
-        .resolve(projectPath, urlOrFilename)
-        .replace(/\\/g, '/');
+      const resourceAbsolutePath = path.resolve(projectPath, urlOrFilename);
+      const resourceUrl = nodeUrl
+        ? nodeUrl.pathToFileURL(resourceAbsolutePath).href
+        : 'file://' +
+          resourceAbsolutePath.replace(/\\/g, '/').replace(/#/g, '%23');
 
       console.info('Caching resolved local filename:', resourceAbsolutePath);
       return this._cache.cacheLocalFileUrl(
         project,
         urlOrFilename,
-        'file://' + resourceAbsolutePath,
+        resourceUrl,
         !!disableCacheBurst
       );
     }

From f5c52b1c7da13e91bdc3772f92b7d8ea48892e0c Mon Sep 17 00:00:00 2001
From: Adam Sardo <adamsardo98@gmail.com>
Date: Sat, 9 May 2026 22:50:32 +1000
Subject: [PATCH 2/3] Fix optionalRequire mock for url module

---
 newIDE/app/src/Utils/__mocks__/OptionalRequire.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/newIDE/app/src/Utils/__mocks__/OptionalRequire.js b/newIDE/app/src/Utils/__mocks__/OptionalRequire.js
index 73a2a6ff20a1..3b8d98704599 100644
--- a/newIDE/app/src/Utils/__mocks__/OptionalRequire.js
+++ b/newIDE/app/src/Utils/__mocks__/OptionalRequire.js
@@ -1,4 +1,5 @@
 import path from 'path';
+import nodeUrl from 'url';
 
 const mockElectron = {
   ipcRenderer: {
@@ -45,6 +46,9 @@ const mockOptionalRequire = jest.fn(
     if (moduleName === 'path') {
       return path;
     }
+    if (moduleName === 'url') {
+      return nodeUrl;
+    }
     if (moduleName === 'os') {
       return mockOs;
     }

From d8c66781a41567d5dba275b466e801bd0095ba3d Mon Sep 17 00:00:00 2001
From: Adam Sardo <adamsardo98@gmail.com>
Date: Sat, 9 May 2026 23:55:12 +1000
Subject: [PATCH 3/3] Add hash resource path regression test

---
 newIDE/app/src/ResourcesLoader/index.spec.js | 34 ++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 newIDE/app/src/ResourcesLoader/index.spec.js

diff --git a/newIDE/app/src/ResourcesLoader/index.spec.js b/newIDE/app/src/ResourcesLoader/index.spec.js
new file mode 100644
index 000000000000..51fad9f7d907
--- /dev/null
+++ b/newIDE/app/src/ResourcesLoader/index.spec.js
@@ -0,0 +1,34 @@
+// @flow
+import ResourcesLoader from './index';
+
+jest.mock('../Utils/OptionalRequire');
+
+describe('ResourcesLoader', () => {
+  let dateNowSpy;
+
+  beforeEach(() => {
+    ResourcesLoader.burstAllUrlsCache();
+    dateNowSpy = jest.spyOn(Date, 'now').mockReturnValue(1234);
+  });
+
+  afterEach(() => {
+    dateNowSpy.mockRestore();
+  });
+
+  test('encodes hash characters in local file URLs before adding cache parameters', () => {
+    const project: any = {
+      ptr: 1,
+      getProjectFile: () => '/project/Game Jam #1/game.json',
+    };
+
+    const resolvedUrl = ResourcesLoader.getFullUrl(
+      project,
+      'Parts/hero #1.png',
+      {}
+    );
+
+    expect(resolvedUrl).toBe(
+      'file:///project/Game%20Jam%20%231/Parts/hero%20%231.png?cache=1234'
+    );
+  });
+});