file_integrity.py: make sure file_fd is always closed on exit

src/borg/crypto/file_integrity.py

@@ -127,6 +127,7 @@ class IntegrityCheckedFile(FileLikeWrapper):
         self.writing = write
         mode = 'wb' if write else 'rb'
         self.file_fd = override_fd or open(path, mode)
+        self.file_opened = override_fd is None
         self.digests = {}
 
         hash_cls = XXH64FileHashingWrapper
@@ -189,9 +190,13 @@ class IntegrityCheckedFile(FileLikeWrapper):
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         exception = exc_type is not None
-        if not exception:
-            self.hash_part('final', is_final=True)
-        self.hasher.__exit__(exc_type, exc_val, exc_tb)
+        try:
+            if not exception:
+                self.hash_part("final", is_final=True)
+            self.hasher.__exit__(exc_type, exc_val, exc_tb)
+        finally:
+            if self.file_opened:
+                self.file_fd.close()
         if exception:
             return
         if self.writing: