MOBILE-2512 prefetch: Don't download hidden modules and sections

src/core/course/providers/helper.ts

@@ -1114,6 +1114,11 @@ export class CoreCourseHelperProvider {
             return Promise.resolve();
         }
 
+        if (section.hiddenbynumsections) {
+            // Hidden section.
+            return Promise.resolve();
+        }
+
         section.isDownloading = true;
 
         // Validate the section needs to be downloaded and calculate amount of modules that need to be downloaded.

src/core/course/providers/module-prefetch-delegate.ts

@@ -953,6 +953,11 @@ export class CoreCourseModulePrefetchDelegate extends CoreDelegate {
      * @return {Promise<boolean>} Promise resolved with true if downloadable, false otherwise.
      */
     isModuleDownloadable(module: any, courseId: number): Promise<boolean> {
+        if (module.uservisible === false) {
+            // Module isn't visible by the user, cannot be downloaded.
+            return Promise.resolve(false);
+        }
+
         const handler = this.getPrefetchHandlerFor(module);
 
         if (handler) {