diff --git a/lib/private/files/cache/cache.php b/lib/private/files/cache/cache.php
index fc2d965d7f9..c1e5b34c8aa 100644
--- a/lib/private/files/cache/cache.php
+++ b/lib/private/files/cache/cache.php
@@ -64,6 +64,10 @@ class Cache {
 	 * @return int
 	 */
 	public function getMimetypeId($mime) {
+		if (empty($mime)) {
+			// Can not insert empty string into Oracle NOT NULL column.
+			$mime = 'application/octet-stream';
+		}
 		if (empty(self::$mimetypeIds)) {
 			$this->loadMimetypes();
 		}
diff --git a/lib/private/files/type/detection.php b/lib/private/files/type/detection.php
index 242a81cb5a4..d7cc9ebbf4e 100644
--- a/lib/private/files/type/detection.php
+++ b/lib/private/files/type/detection.php
@@ -61,8 +61,6 @@ class Detection {
 	 * @return string
 	 */
 	public function detect($path) {
-		$isWrapped = (strpos($path, '://') !== false) and (substr($path, 0, 7) === 'file://');
-
 		if (@is_dir($path)) {
 			// directories are easy
 			return "httpd/unix-directory";
@@ -76,9 +74,11 @@ class Detection {
 			$info = @strtolower(finfo_file($finfo, $path));
 			if ($info) {
 				$mimeType = substr($info, 0, strpos($info, ';'));
+				return empty($mimeType) ? 'application/octet-stream' : $mimeType;
 			}
 			finfo_close($finfo);
 		}
+		$isWrapped = (strpos($path, '://') !== false) and (substr($path, 0, 7) === 'file://');
 		if (!$isWrapped and $mimeType === 'application/octet-stream' && function_exists("mime_content_type")) {
 			// use mime magic extension if available
 			$mimeType = mime_content_type($path);
@@ -94,6 +94,10 @@ class Detection {
 			//trim the newline
 			$mimeType = trim($reply);
 
+			if (empty($mimeType)) {
+				$mimeType = 'application/octet-stream';
+			}
+
 		}
 		return $mimeType;
 	}