From 7cffec1d26a065c9dbbc662b09110c28a2549c36 Mon Sep 17 00:00:00 2001
From: Edwin Eefting <edwin@datux.nl>
Date: Tue, 26 Sep 2023 16:16:32 +0200
Subject: [PATCH] check guid of common snapshot, fix #218

---
 tests/test_zfsautobackup32.py | 101 ++++++++++++++++++++++++++++++++++
 zfs_autobackup/ZfsDataset.py  |  17 +++++-
 2 files changed, 115 insertions(+), 3 deletions(-)
 create mode 100644 tests/test_zfsautobackup32.py

diff --git a/tests/test_zfsautobackup32.py b/tests/test_zfsautobackup32.py
new file mode 100644
index 0000000..ed1109d
--- /dev/null
+++ b/tests/test_zfsautobackup32.py
@@ -0,0 +1,101 @@
+from basetest import *
+import time
+
+class TestZfsAutobackup32(unittest2.TestCase):
+    """various new 3.2 features"""
+
+    def setUp(self):
+        prepare_zpools()
+        self.longMessage=True
+
+    def test_invalid_common_snapshot(self):
+
+        with patch('time.strftime', return_value="test-20101111000000"):
+            self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --allow-empty".split(" ")).run())
+
+        #create 2 snapshots with the same name, which are invalid as common snapshot
+        shelltest("zfs snapshot test_source1/fs1@invalid")
+        shelltest("zfs snapshot test_target1/test_source1/fs1@invalid")
+
+        with patch('time.strftime', return_value="test-20101111000001"):
+            self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --allow-empty".split(" ")).run())
+
+            r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
+            self.assertMultiLineEqual(r,"""
+test_source1
+test_source1/fs1
+test_source1/fs1@test-20101111000000
+test_source1/fs1@invalid
+test_source1/fs1@test-20101111000001
+test_source1/fs1/sub
+test_source1/fs1/sub@test-20101111000000
+test_source1/fs1/sub@test-20101111000001
+test_source2
+test_source2/fs2
+test_source2/fs2/sub
+test_source2/fs2/sub@test-20101111000000
+test_source2/fs2/sub@test-20101111000001
+test_source2/fs3
+test_source2/fs3/sub
+test_target1
+test_target1/test_source1
+test_target1/test_source1/fs1
+test_target1/test_source1/fs1@test-20101111000000
+test_target1/test_source1/fs1@invalid
+test_target1/test_source1/fs1@test-20101111000001
+test_target1/test_source1/fs1/sub
+test_target1/test_source1/fs1/sub@test-20101111000000
+test_target1/test_source1/fs1/sub@test-20101111000001
+test_target1/test_source2
+test_target1/test_source2/fs2
+test_target1/test_source2/fs2/sub
+test_target1/test_source2/fs2/sub@test-20101111000000
+test_target1/test_source2/fs2/sub@test-20101111000001
+""")
+
+    def test_invalid_common_snapshot_with_data(self):
+
+        with patch('time.strftime', return_value="test-20101111000000"):
+            self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --allow-empty".split(" ")).run())
+
+        #create 2 snapshots with the same name, which are invalid as common snapshot
+        shelltest("zfs snapshot test_source1/fs1@invalid")
+        shelltest("zfs mount test_target1/test_source1/fs1")
+        shelltest("touch /test_target1/test_source1/fs1/shouldnotbeHere")
+        shelltest("zfs snapshot test_target1/test_source1/fs1@invalid")
+
+        with patch('time.strftime', return_value="test-20101111000001"):
+            self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --allow-empty --destroy-incompatible".split(" ")).run())
+
+            r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
+            self.assertMultiLineEqual(r,"""
+test_source1
+test_source1/fs1
+test_source1/fs1@test-20101111000000
+test_source1/fs1@invalid
+test_source1/fs1@test-20101111000001
+test_source1/fs1/sub
+test_source1/fs1/sub@test-20101111000000
+test_source1/fs1/sub@test-20101111000001
+test_source2
+test_source2/fs2
+test_source2/fs2/sub
+test_source2/fs2/sub@test-20101111000000
+test_source2/fs2/sub@test-20101111000001
+test_source2/fs3
+test_source2/fs3/sub
+test_target1
+test_target1/test_source1
+test_target1/test_source1/fs1
+test_target1/test_source1/fs1@test-20101111000000
+test_target1/test_source1/fs1@test-20101111000001
+test_target1/test_source1/fs1/sub
+test_target1/test_source1/fs1/sub@test-20101111000000
+test_target1/test_source1/fs1/sub@test-20101111000001
+test_target1/test_source2
+test_target1/test_source2/fs2
+test_target1/test_source2/fs2/sub
+test_target1/test_source2/fs2/sub@test-20101111000000
+test_target1/test_source2/fs2/sub@test-20101111000001
+""")
+
diff --git a/zfs_autobackup/ZfsDataset.py b/zfs_autobackup/ZfsDataset.py
index 06cf613..cbea0dc 100644
--- a/zfs_autobackup/ZfsDataset.py
+++ b/zfs_autobackup/ZfsDataset.py
@@ -58,6 +58,13 @@ class ZfsDataset:
         """
         self.zfs_node.error("{}: {}".format(self.name, txt))
 
+    def warning(self, txt):
+        """
+        Args:
+            :type txt: str
+        """
+        self.zfs_node.warning("{}: {}".format(self.name, txt))
+
     def debug(self, txt):
         """
         Args:
@@ -822,9 +829,13 @@ class ZfsDataset:
             return None
         else:
             for source_snapshot in reversed(self.snapshots):
-                if target_dataset.find_snapshot(source_snapshot):
-                    source_snapshot.debug("common snapshot")
-                    return source_snapshot
+                target_snapshot=target_dataset.find_snapshot(source_snapshot)
+                if target_snapshot:
+                    if source_snapshot.properties['guid']!=target_snapshot.properties['guid']:
+                        source_snapshot.warning("Common snapshot has invalid guid, ignoring.")
+                    else:
+                        source_snapshot.debug("common snapshot")
+                        return source_snapshot
             target_dataset.error("Cant find common snapshot with source.")
             raise (Exception("You probably need to delete the target dataset to fix this."))