Plot style and plotter files save atomically through write_atomic (#1928 follow-up)

crates/engine/src/cmd/layout/plotstyle.rs

@@ -332,9 +332,8 @@ fn run_stylesmanager(s: &mut Session, p: &Value) -> Result<Value> {
                 Some(_path) => {
                     #[cfg(not(target_arch = "wasm32"))]
                     {
-                        let tmp = format!("{_path}.cadcraft-tmp");
-                        std::fs::write(&tmp, text.as_bytes()).map_err(|e| bad(cmd, format!("{_path}: {e}")))?;
-                        std::fs::rename(&tmp, _path).map_err(|e| bad(cmd, format!("{_path}: {e}")))?;
+                        crate::atomic_write::write_atomic(std::path::Path::new(_path), text.as_bytes())
+                            .map_err(|e| bad(cmd, format!("{_path}: {e}")))?;
                         Ok(json!({ "name": name, "path": _path, "bytes": text.len() }))
                     }
                     #[cfg(target_arch = "wasm32")]

crates/engine/src/cmd/plotters.rs

@@ -110,9 +110,7 @@ impl PlotterStore {
             write: |n, t| {
                 let p = file(n)?;
                 std::fs::create_dir_all(dir()?).map_err(|e| e.to_string())?;
-                let tmp = p.with_extension("json.cadcraft-tmp");
-                std::fs::write(&tmp, t).map_err(|e| format!("{n}: {e}"))?;
-                std::fs::rename(&tmp, &p).map_err(|e| format!("{n}: {e}"))
+                crate::atomic_write::write_atomic(&p, t.as_bytes()).map_err(|e| format!("{n}: {e}"))
             },
             delete: |n| std::fs::remove_file(file(n)?).map_err(|e| format!("{n}: {e}")),
         }

crates/engine/tests/plot_styles.rs

@@ -104,3 +104,30 @@ fn stylesmanager_creates_edits_saves_and_loads_tables() {
     // Undo takes a table edit back.
     s.execute("undo", &json!({})).unwrap();
 }
+
+/// Issue #1928: saving a plot style table to a file goes through the atomic writer: a symlink
+/// planted at the old fixed temporary name is left alone, and the file keeps its permissions.
+#[cfg(unix)]
+#[test]
+fn plot_style_save_is_atomic_and_keeps_permissions() {
+    use std::os::unix::fs::PermissionsExt;
+    let dir = std::env::temp_dir().join(format!("cadcraft-pstyle-atomic-{}", std::process::id()));
+    let _ = std::fs::remove_dir_all(&dir);
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("office.stb.json");
+    std::fs::write(&path, "old").unwrap();
+    std::fs::set_permissions(&path, std::fs::Permissions::from_mode(0o600)).unwrap();
+    let victim = dir.join("victim");
+    std::fs::write(&victim, "keep").unwrap();
+    std::os::unix::fs::symlink(&victim, dir.join("office.stb.json.cadcraft-tmp")).unwrap();
+
+    let mut s = Session::new();
+    s.execute("stylesmanager", &json!({"action": "new", "name": "office.stb"})).unwrap();
+    let p = path.to_string_lossy().to_string();
+    s.execute("stylesmanager", &json!({"action": "save", "name": "office.stb", "path": p})).unwrap();
+
+    assert_ne!(std::fs::read_to_string(&path).unwrap(), "old");
+    assert_eq!(std::fs::read_to_string(&victim).unwrap(), "keep");
+    assert_eq!(std::fs::metadata(&path).unwrap().permissions().mode() & 0o777, 0o600);
+    let _ = std::fs::remove_dir_all(&dir);
+}