fix(updating): don't skip gitignored .rej files when converting to inline conflict markers (#2668)

Author: rcoup

copier/_main.py

@@ -1529,12 +1529,16 @@ def _apply_update(self) -> None:  # noqa: C901
                     conflicted = []
                     old_path = Path(old_copy)
                     new_path = Path(new_copy)
-                    status = git("status", "--porcelain").strip().splitlines()
+                    # `--ignored` so we still find .rej files when the
+                    # destination has a `*.rej` ignore rule.
+                    status = (
+                        git("status", "--porcelain", "--ignored").strip().splitlines()
+                    )
                     for line in status:
                         # Filter merge rejections (part 1/2)
-                        if not line.startswith("?? "):
+                        if not line.startswith(("?? ", "!! ")):
                             continue
-                        # Remove "?? " prefix
+                        # Remove prefix
                         fname = line[3:]
                         # Normalize name
                         fname = normalize_git_path(fname)

tests/test_updatediff.py

@@ -1284,6 +1284,7 @@ def function_two():
     )
 
 
+@pytest.mark.parametrize("gitignore_rej", [False, True])
 @pytest.mark.parametrize(
     "filename",
     [
@@ -1297,6 +1298,7 @@ def function_two():
 def test_conflicted_files_are_marked_unmerged(
     tmp_path_factory: pytest.TempPathFactory,
     filename: str,
+    gitignore_rej: bool,
 ) -> None:
     # Template in v1 has a file with a single line;
     # in v2 it changes that line.
@@ -1325,6 +1327,17 @@ def test_conflicted_files_are_marked_unmerged(
     with local.cwd(dst):
         git_init("hello project")
 
+        # Optionally gitignore .rej files. Inline-conflict resolution
+        # must still produce inline markers — the .rej is just an
+        # internal artifact of the resolution, never something the
+        # downstream user wants to see, so it's reasonable for them to
+        # ignore it. Regression for the case where copier's `git status
+        # --porcelain` invocation silently dropped ignored .rej files.
+        if gitignore_rej:
+            Path(".gitignore").write_text("*.rej\n")
+            git("add", ".gitignore")
+            git("commit", "-m", "ignore .rej files")
+
         # After first commit, change the file, commit again
         Path(filename).write_text("upstream version 1 + downstream")
         git("commit", "-am", "updated file")