git: Use -z for null separated parsing

revup/amend.py

@@ -158,7 +158,9 @@ async def rebuild_stack_last_touched(
     Rebuild the stack, amending each staged file into the most recent commit that touched it.
     Returns the new HEAD commit.
     """
-    # Map each staged file to its most recent commit in the stack (ordered oldest-first)
+    # Map each staged file to its most recent commit in the stack (ordered oldest-first).
+    # -z gives NUL-terminated, unquoted paths so names with spaces, quotes, or unicode
+    # match staged_files (also -z) exactly rather than git's default C-quoted form.
     file_to_commit: Dict[str, int] = {}
     for i, commit_obj in enumerate(stack):
         touched = await git_ctx.git_stdout(
@@ -167,9 +169,10 @@ async def rebuild_stack_last_touched(
             "--name-only",
             "-r",
             "--no-renames",
+            "-z",
             commit_obj.commit_id,
         )
-        for f in touched.split("\n"):
+        for f in touched.split("\0"):
             if f and f in staged_files:
                 file_to_commit[f] = i
 
@@ -185,8 +188,8 @@ async def rebuild_stack_last_touched(
     # A staged deletion has no entry here; its path stays out of staged_entries so
     # the overlay omits it, which the pre-image merge base below turns into a removal.
     staged_entries: Dict[str, str] = {}
-    ls_output = await git_ctx.git_stdout("ls-files", "--stage", "--", *files_to_amend)
-    for line in ls_output.split("\n"):
+    ls_output = await git_ctx.git_stdout("ls-files", "--stage", "-z", "--", *files_to_amend)
+    for line in ls_output.split("\0"):
         if not line:
             continue
         _, path = line.split("\t", 1)
@@ -286,7 +289,7 @@ async def get_has_unstaged() -> bool:
 
     if args.last_touched:
         staged_files_output = await git_ctx.git_stdout(
-            "diff-index", "--cached", "-r", "--name-only", "--no-renames", "HEAD"
+            "diff-index", "--cached", "-r", "--name-only", "--no-renames", "-z", "HEAD"
         )
         if not staged_files_output:
             return 0
@@ -304,7 +307,7 @@ async def get_has_unstaged() -> bool:
         if not stack:
             return 0
 
-        staged_files = set(staged_files_output.split("\n"))
+        staged_files = set(f for f in staged_files_output.split("\0") if f)
         new_commit = await rebuild_stack_last_touched(git_ctx, stack, staged_files)
         if not new_commit:
             return 0

revup/git.py

@@ -630,9 +630,11 @@ async def make_tree_from_paths(self, tree: GitTreeHash, paths: List[str]) -> Git
         """
         if not paths:
             return await self.empty_tree()
-        ls_output = await self.git_stdout("ls-tree", "-r", tree, "--", *paths)
+        # -z gives NUL-terminated, unquoted paths so names with special chars or
+        # unicode aren't C-quoted, matching make_tree_from_index_entries's format.
+        ls_output = await self.git_stdout("ls-tree", "-r", "-z", tree, "--", *paths)
         entries = []
-        for line in ls_output.split("\n"):
+        for line in ls_output.split("\0"):
             if not line:
                 continue
             meta, path = line.split("\t", 1)

tests/test_amend.py

@@ -996,3 +996,27 @@ async def test_staged_deletion_amended_into_last_commit(self):
             assert await env.get_file_at_commit("keep.txt", "HEAD~1") == "k"
             assert await env.get_file_at_commit("b.txt", "HEAD") == "b1"
             assert not await env.has_staged_changes()
+
+    @async_test
+    async def test_paths_with_special_chars_and_unicode(self):
+        # git C-quotes paths with spaces/unicode unless -z is used; exercise both
+        # a modification and a deletion of such paths in one run.
+        async with GitTestEnvironment() as env:
+            await env.commit("root", {"root.txt": "r"})
+            await env.git_ctx.git("branch", "origin/main", "HEAD")
+            await env.commit(
+                "first\n\nTopic: alpha",
+                {"süb dir/fïle a.txt": "v1", "dél été.txt": "d1"},
+            )
+            await env.commit("second\n\nTopic: beta", {"b.txt": "b1"})
+
+            # Modify the unicode/space path and delete another such path.
+            await env.stage_file("süb dir/fïle a.txt", "v2")
+            await env.git_ctx.git("rm", "dél été.txt")
+            args = make_amend_args(last_touched=True, parse_topics=True)
+            await amend.main(args, env.git_ctx)
+
+            assert await env.get_file_at_commit("süb dir/fïle a.txt", "HEAD~1") == "v2"
+            assert await env.git_ctx.git_return_code("cat-file", "-e", "HEAD:dél été.txt") != 0
+            assert await env.get_file_at_commit("b.txt", "HEAD") == "b1"
+            assert not await env.has_staged_changes()