Fix _apply_move scope, _revision_only_mode branch guard, and docstrings

- git.py _apply_move: narrow try/except to cover only move_directory_contents
  so the "didn't match any files" warning is not emitted for a safe_rm
  failure after a successful move; return early on FileNotFoundError
- subproject.py _revision_only_mode: remove the not-branch guard so the
  predicate matches check_wanted_with_local (revision + revision_is_enough
  is sufficient, branch presence is irrelevant)
- git.py ignored_files / any_changes_or_untracked: document the intentional
  asymmetry — ignored_files returns [] for a missing path while
  any_changes_or_untracked raises RuntimeError because callers must verify
  existence first

https://claude.ai/code/session_01Doq8oQtBRH4afusvp9Dv4p

Author: claude

dfetch/project/subproject.py

@@ -374,11 +374,7 @@ def _on_disk_hash(self) -> str | None:
 
     def _revision_only_mode(self) -> bool:
         """Return True when the wanted version should be resolved by revision alone."""
-        return (
-            not self.wanted_version.branch
-            and bool(self.wanted_version.revision)
-            and self.revision_is_enough()
-        )
+        return bool(self.wanted_version.revision) and self.revision_is_enough()
 
     def _check_for_newer_version(self) -> Version | None:
         """Check if a newer version is available on the given branch.

dfetch/vcs/git.py

@@ -443,13 +443,14 @@ def _apply_move(chosen: Path, repo_root: Path, remote: str) -> None:
         """Move the contents of *chosen* to the repo root and remove the empty parent."""
         try:
             move_directory_contents(str(chosen), ".")
-            parts = chosen.relative_to(repo_root).parts
-            if parts:
-                safe_rm(repo_root / parts[0], within=repo_root)
         except FileNotFoundError:
             logger.warning(
                 f"The 'src:' filter '{chosen}' didn't match any files from '{remote}'"
             )
+            return
+        parts = chosen.relative_to(repo_root).parts
+        if parts:
+            safe_rm(repo_root / parts[0], within=repo_root)
 
     @staticmethod
     def _move_src_folder_up(remote: str, src: str) -> None:
@@ -569,7 +570,11 @@ def create_diff(
         return str(result.stdout.decode())
 
     def ignored_files(self) -> Sequence[str]:
-        """List of ignored files in this repository."""
+        """List of ignored files in this repository.
+
+        Returns an empty list if the repository path does not exist (e.g. during
+        an initial fetch before the local copy has been created).
+        """
         if not Path(self._path).exists():
             return []
 
@@ -591,7 +596,12 @@ def ignored_files(self) -> Sequence[str]:
             )
 
     def any_changes_or_untracked(self) -> bool:
-        """Return True if the repo has any changed or untracked files."""
+        """Return True if the repo has any changed or untracked files.
+
+        Raises RuntimeError if the repository path does not exist.  Callers are
+        expected to verify existence first (e.g. via on_disk_version) before
+        invoking this method.
+        """
         if not Path(self._path).exists():
             raise RuntimeError("Path does not exist.")