Prevent error in files_trashbin

`glob` can return FALSE when the directory is empty, instead of an empty array,
causing an error at `foreach`.

"Note: On some systems it is impossible to distinguish between empty match and
an error."

See http://www.php.net/manual/en/function.glob.php -> Return Values

1 files changed, 9 insertions, 7 deletions

diff --git a/apps/files_trashbin/lib/trashbin.php b/apps/files_trashbin/lib/trashbin.php
index bf8d465e5de..9b931333b7f 100644
--- a/apps/files_trashbin/lib/trashbin.php
+++ b/apps/files_trashbin/lib/trashbin.php
@@ -824,13 +824,15 @@ class Trashbin {
 			$matches = glob($escapedVersionsName . '*');
 		}
 
-		foreach ($matches as $ma) {
-			if ($timestamp) {
-				$parts = explode('.v', substr($ma, 0, $offset));
-				$versions[] = (end($parts));
-			} else {
-				$parts = explode('.v', $ma);
-				$versions[] = (end($parts));
+		if (is_array($matches)) {
+			foreach ($matches as $ma) {
+				if ($timestamp) {
+					$parts = explode('.v', substr($ma, 0, $offset));
+					$versions[] = (end($parts));
+				} else {
+					$parts = explode('.v', $ma);
+					$versions[] = (end($parts));
+				}
 			}
 		}
 		return $versions;