zfs-check broken pipe handling tests

tests/test_check.py

@@ -107,7 +107,21 @@ dir/testfile	0	2e863f1fcccd6642e4e28453eba10d2d3f74d798
 """, buf.getvalue())
 
 
-    # def test_brokenpipe_cleanup_filesystem(self):
-    #     """test if stuff is cleaned up correctly, in debugging mode , when a pipe breaks. """
+    def test_brokenpipe_cleanup_filesystem(self):
+        """test if stuff is cleaned up correctly, in debugging mode , when a pipe breaks. """
+
+        prepare_zpools()
+        shelltest("cp tests/data/whole /test_source1/testfile")
+        shelltest("zfs snapshot test_source1@test")
+
+        #breaks pipe when grep exists:
+        #important to use --debug, since that generates extra output which would be problematic if we didnt do correct SIGPIPE handling
+        shelltest("python -m zfs_autobackup.ZfsCheck test_source1@test --debug | grep -m1 Hashing")
+
+        #should NOT be mounted anymore if cleanup went ok:
+        self.assertNotRegex(shelltest("mount"), "test_source1@test")
+
+
+