[stable31] fix(files): Always return a valid mimetype

apps/files_trashbin/lib/Trash/TrashItem.php

@@ -69,7 +69,7 @@ public function getPath() {
 		return $this->fileInfo->getPath();
 	}
 
-	public function getMimetype() {
+	public function getMimetype(): string {
 		return $this->fileInfo->getMimetype();
 	}
 

lib/private/Files/Cache/CacheEntry.php

@@ -65,8 +65,8 @@ public function getName() {
 	}
 
 
-	public function getMimeType() {
-		return $this->data['mimetype'];
+	public function getMimeType(): string {
+		return $this->data['mimetype'] ?? 'application/octet-stream';
 	}
 
 

lib/private/Files/FileInfo.php

@@ -133,11 +133,8 @@ public function getId() {
 		return isset($this->data['fileid']) ? (int)$this->data['fileid'] : null;
 	}
 
-	/**
-	 * @return string
-	 */
-	public function getMimetype() {
-		return $this->data['mimetype'];
+	public function getMimetype(): string {
+		return $this->data['mimetype'] ?? 'application/octet-stream';
 	}
 
 	/**

lib/private/Files/Node/LazyFolder.php

@@ -314,10 +314,7 @@ public function getUserFolder($userId) {
 		return $this->__call(__FUNCTION__, func_get_args());
 	}
 
-	/**
-	 * @inheritDoc
-	 */
-	public function getMimetype() {
+	public function getMimetype(): string {
 		if (isset($this->data['mimetype'])) {
 			return $this->data['mimetype'];
 		}

lib/private/Files/Node/Node.php

@@ -339,7 +339,7 @@ public function isShared() {
 		return $this->getFileInfo(false)->isShared();
 	}
 
-	public function getMimeType() {
+	public function getMimeType(): string {
 		return $this->getFileInfo(false)->getMimetype();
 	}
 

lib/private/Files/Node/NonExistingFile.php

@@ -122,7 +122,7 @@ public function putContent($data) {
 		throw new NotFoundException();
 	}
 
-	public function getMimeType() {
+	public function getMimeType(): string {
 		if ($this->fileInfo) {
 			return parent::getMimeType();
 		} else {

lib/public/Files/Cache/ICacheEntry.php

@@ -60,10 +60,9 @@ public function getName();
 	/**
 	 * Get the full mimetype
 	 *
-	 * @return string
 	 * @since 9.0.0
 	 */
-	public function getMimeType();
+	public function getMimeType(): string;
 
 	/**
 	 * Get the first part of the mimetype

lib/public/Files/File.php

@@ -43,10 +43,9 @@ public function putContent($data);
 	/**
 	 * Get the mimetype of the file
 	 *
-	 * @return string
 	 * @since 6.0.0
 	 */
-	public function getMimeType();
+	public function getMimeType(): string;
 
 	/**
 	 * Open the file as stream, resulting resource can be operated as stream like the result from php's own fopen

lib/public/Files/FileInfo.php

@@ -103,10 +103,9 @@ public function getPath();
 	/**
 	 * Get the full mimetype of the file or folder i.e. 'image/png'
 	 *
-	 * @return string
 	 * @since 7.0.0
 	 */
-	public function getMimetype();
+	public function getMimetype(): string;
 
 	/**
 	 * Get the first part of the mimetype of the file or folder i.e. 'image'