Overlapping path check too strict

Fixes #684

dfetch/commands/update.py

@@ -21,6 +21,7 @@
 
 import argparse
 import os
+from pathlib import Path
 from typing import Any  # pylint: disable=unused-import
 from typing import List
 
@@ -141,12 +142,23 @@ def _check_overlapping_destination(
         real_path: str,
     ) -> None:
         """Check if project will try to write to the same destination."""
-        common_prefixes = [
-            os.path.commonprefix((real_path, dst))
+        wanted_dest = Path(real_path)
+
+        common_paths = [
+            dst
             for dst in destinations
-            if dst != real_path
+            if wanted_dest in Path(dst).parents
+            or Path(dst) in wanted_dest.parents
+            or wanted_dest == Path(dst)
         ]
-        if destinations.count(real_path) > 1 or real_path in common_prefixes:
+
+        duplicates = common_paths.count(real_path)
+        try:
+            common_paths.remove(real_path)
+        except ValueError:
+            pass
+
+        if duplicates > 1 or common_paths:
             logger.print_warning_line(
                 project.name,
                 f'Skipping due to overlapping destination: "{project.destination}"',

tests/test_update.py

@@ -118,3 +118,24 @@ def test_check_overlapping_destinations(name, real_path, destinations):
         Update._check_overlapping_destination(
             ProjectEntry.from_yaml({"name": "a"}), destinations, real_path
         )
+
+
+@pytest.mark.parametrize(
+    "name, real_path, destinations",
+    [
+        (
+            "sub-folder",
+            "/somewhere/sub",
+            ["/somewhere/sub", "/somewhere/sub1", "/somewhere/sub2"],
+        ),
+        (
+            "sub-folders",
+            "/somewhere/sub1",
+            ["/somewhere/sub1", "/somewhere/sub/sub1", "/somewhere/sub2"],
+        ),
+    ],
+)
+def test_check_non_overlapping_destinations(name, real_path, destinations):
+    Update._check_overlapping_destination(
+        ProjectEntry.from_yaml({"name": "a"}), destinations, real_path
+    )