Merge pull request #2319 from gavenren/fix/join-path-leading-separators

fix(util): preserve separators before relative path tokens

Author: Byron

git/util.py

@@ -235,15 +235,16 @@ def stream_copy(source: SupportsRead[AnyStr], destination: SupportsWrite[AnyStr]
 
 def join_path(a: PathLike, *p: PathLike) -> PathLike:
     R"""Join path tokens together similar to osp.join, but always use ``/`` instead of
-    possibly ``\`` on Windows."""
+    possibly ``\`` on Windows.
+
+    Later tokens are treated as relative, even when they start with ``/``.
+    """
     path = os.fspath(a)
     for b in p:
-        b = os.fspath(b)
+        b = os.fspath(b).lstrip("/")
         if not b:
             continue
-        if b.startswith("/"):
-            path += b[1:]
-        elif path == "" or path.endswith("/"):
+        if path == "" or path.endswith("/"):
             path += b
         else:
             path += "/" + b

test/test_util.py

@@ -38,6 +38,7 @@
     decygpath,
     get_user_id,
     is_cygwin_git,
+    join_path,
     remove_password_if_present,
     rmtree,
 )
@@ -46,6 +47,26 @@
 from test.lib import TestBase, requires_symlinks, with_rw_repo
 
 
+@pytest.mark.parametrize(
+    "parts, expected",
+    [
+        (("parent", "/child"), "parent/child"),
+        (("parent", "/child", "/leaf"), "parent/child/leaf"),
+        ((pathlib.Path("parent"), "/child"), "parent/child"),
+        (("parent/", "/child"), "parent/child"),
+        (("parent", "child"), "parent/child"),
+        (("", "/child"), "child"),
+        (("/", "/child"), "/child"),
+        (("parent", "", "child"), "parent/child"),
+        (("parent", "//child"), "parent/child"),
+        (("/parent/", "///child"), "/parent/child"),
+        (("parent", "///"), "parent"),
+    ],
+)
+def test_join_path_keeps_later_tokens_relative(parts, expected):
+    assert join_path(*parts) == expected
+
+
 @pytest.fixture
 def tmp_path(request):
     # Unreadable files and symlinks cannot be copied by native fixture tooling.