fix(SimpleFile): Catch exception and call checkFile() to sanitize broken appdata folder

lib/private/Files/Node/File.php

@@ -9,6 +9,7 @@
 
 use OCP\Constants;
 use OCP\Files\GenericFileException;
+use OCP\Files\NotFoundException;
 use OCP\Files\NotPermittedException;
 use OCP\Lock\LockedException;
 
@@ -35,7 +36,7 @@ public function getContent() {
 		if ($this->checkPermissions(Constants::PERMISSION_READ)) {
 			$content = $this->view->file_get_contents($this->path);
 			if ($content === false) {
-				throw new GenericFileException();
+				throw new GenericFileException('file_get_contents failed');
 			}
 			return $content;
 		} else {
@@ -66,6 +67,7 @@ public function putContent($data) {
 	/**
 	 * @param string $mode
 	 * @return resource|false
+	 * @throws NotFoundException
 	 * @throws NotPermittedException
 	 * @throws LockedException
 	 */

lib/private/Files/SimpleFS/SimpleFile.php

@@ -54,27 +54,25 @@ public function getMTime(): int {
 	/**
 	 * Get the content
 	 *
-	 * @throws GenericFileException
 	 * @throws LockedException
 	 * @throws NotFoundException
 	 * @throws NotPermittedException
 	 */
 	#[\Override]
-	public function getContent(): string {
-		$result = $this->file->getContent();
-
-		if ($result === false) {
+	public function getContent(): string|bool {
+		try {
+			return $this->file->getContent();
+		} catch (GenericFileException) {
 			$this->checkFile();
 		}
 
-		return $result;
+		return false;
 	}
 
 	/**
 	 * Overwrite the file
 	 *
 	 * @param string|resource $data
-	 * @throws GenericFileException
 	 * @throws LockedException
 	 * @throws NotFoundException
 	 * @throws NotPermittedException
@@ -83,7 +81,7 @@ public function getContent(): string {
 	public function putContent($data): void {
 		try {
 			$this->file->putContent($data);
-		} catch (NotFoundException $e) {
+		} catch (GenericFileException) {
 			$this->checkFile();
 		}
 	}

lib/public/Files/SimpleFS/ISimpleFile.php

@@ -58,7 +58,7 @@ public function getMTime(): int;
 	 * @throws NotPermittedException
 	 * @since 11.0.0
 	 */
-	public function getContent(): string;
+	public function getContent(): string|bool;
 
 	/**
 	 * Overwrite the file

tests/lib/Files/SimpleFS/SimpleFileTest.php

@@ -10,6 +10,7 @@
 use OC\Files\SimpleFS\SimpleFile;
 use OCP\Files\File;
 use OCP\Files\Folder;
+use OCP\Files\GenericFileException;
 use OCP\Files\NotFoundException;
 
 class SimpleFileTest extends \Test\TestCase {
@@ -92,7 +93,7 @@ public function testGetMimeType(): void {
 
 	public function testGetContentInvalidAppData(): void {
 		$this->file->method('getContent')
-			->willReturn(false);
+			->willThrowException(new GenericFileException());
 		$this->file->method('stat')->willReturn(false);
 
 		$parent = $this->createMock(Folder::class);
@@ -109,6 +110,20 @@ public function testGetContentInvalidAppData(): void {
 		$this->simpleFile->getContent();
 	}
 
+	public function testGetContentReturnsFalseOnFailure(): void {
+		$this->file->expects($this->once())
+			->method('getContent')
+			->willThrowException(new GenericFileException());
+
+		// We don't want to test the `checkFile()`
+		// method, so, just return an empty array.
+		$this->file->method('stat')->willReturn([]);
+
+		$result = $this->simpleFile->getContent();
+
+		$this->assertFalse($result);
+	}
+
 	public function testRead(): void {
 		$this->file->expects($this->once())
 			->method('fopen')