Leave the config alone when only its generated comments differ

fnd/config.py

@@ -1053,9 +1053,10 @@ def load(path: Path | None = None) -> Config:
 def ensure_current(config_path: Path | None = None) -> list[str]:
     """Rewrite the config in the current shape, keeping a timestamped backup.
 
-    Returns what was applied, empty when the file was already current. Called
-    once at startup so every config converges on one syntax rather than each
-    legacy shape being honoured forever.
+    Returns what was applied, empty when the file already holds the current
+    values: builds that word a hint differently must not rewrite each other's
+    file. Called once at startup so every config converges on one syntax rather
+    than each legacy shape being honoured forever.
     """
     from fnd._perms import secure_write_text
     from fnd.config_migrations import migrate
@@ -1069,7 +1070,7 @@ def ensure_current(config_path: Path | None = None) -> list[str]:
     version, applied = migrate(raw)
     config = Config.model_validate(raw)
     rendered = render_config(config, preserved=extract_preserved(text), version=version)
-    if rendered == text:
+    if rendered == text or tomllib.loads(rendered) == tomllib.loads(text):
         return []
     _refuse_lossy(rendered, config, raw)
     stamp = dt.datetime.now().strftime("%Y%m%d-%H%M%S")

tests/test_config_render.py

@@ -617,6 +617,26 @@ def test_ensure_current_is_a_no_op_on_a_current_file(self, tmp_path: Path) -> No
         assert conf.ensure_current(path) == []
         assert not list(tmp_path.glob("config.toml.bak-*"))
 
+    def test_reworded_generated_comments_alone_are_not_rewritten(self, tmp_path: Path) -> None:
+        """Builds that word a hint differently otherwise rewrite each other's file on launch."""
+        path = tmp_path / "config.toml"
+        current = render_config(_sample())
+        older = current.replace("# fnd configuration.", "# fnd configuration, older wording.")
+        assert older != current
+        path.write_text(older, encoding="utf-8")
+        assert conf.ensure_current(path) == []
+        assert path.read_text(encoding="utf-8") == older
+        assert not list(tmp_path.glob("config.toml.bak-*"))
+
+    def test_a_value_in_a_non_canonical_form_is_still_rewritten(self, tmp_path: Path) -> None:
+        path = tmp_path / "config.toml"
+        current = render_config(_sample())
+        assert '"~/Notes"' in current
+        absolute = f"'{Path.home() / 'Notes'}'"  # a literal string, so Windows backslashes parse
+        path.write_text(current.replace('"~/Notes"', absolute), encoding="utf-8")
+        assert conf.ensure_current(path) == ["Adopt the canonical layout"]
+        assert path.read_text(encoding="utf-8") == current
+
 
 class TestWritersStayCanonical:
     @pytest.mark.parametrize(

tests/test_match_nav_integration.py

@@ -599,8 +599,10 @@ async def test_stops_hold_their_rows_while_a_scroll_awaits_its_render(
             message=f"the stops never read as settled at y={start}",
         )
         if state == "visible_map":
-            # The render Textual makes after a scroll: visible widgets only.
-            app.screen._refresh_layout(scroll=True)
+            # Textual's post-scroll fast path, called directly: the screen takes
+            # it only while no widget has a layout pending, which a slow runner
+            # does not guarantee.
+            app.screen._compositor.reflow_visible(app.screen, app.screen.outer_size)
             assert app.screen._compositor._visible_map is not None
 
         pane.scroll_to(y=end, animate=False, immediate=True)