cli: create new wc_commit when wc_commit become immuable

CHANGELOG.md

@@ -110,6 +110,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   rebase the children of the revision being split if they had other parents
   (i.e. if the child was a merge).
 
+* When the working copy commit becomes immutable, a new one is automatically created on top of it 
+to avoid letting the user edit the immutable one.
+
 * The `snapshot.max-new-file-size` option can now handle raw integer literals,
   interpreted as a number of bytes, where previously it could only handle string
   literals. This means that `snapshot.max-new-file-size="1"` and

cli/src/cli_util.rs

@@ -1106,8 +1106,9 @@ impl WorkspaceCommandHelper {
         self.commit_summary_template().format(commit, formatter)
     }
 
-    pub fn check_rewritable<'a>(
+    fn check_repo_rewritable<'a>(
         &self,
+        repo: &dyn Repo,
         commits: impl IntoIterator<Item = &'a CommitId>,
     ) -> Result<(), CommandError> {
         if self.global_args.ignore_immutable {
@@ -1127,7 +1128,12 @@ impl WorkspaceCommandHelper {
             .map_err(|e| {
                 config_error_with_message("Invalid `revset-aliases.immutable_heads()`", e)
             })?;
-        let mut expression = self.attach_revset_evaluator(immutable)?;
+        let mut expression = RevsetExpressionEvaluator::new(
+            repo,
+            self.revset_extensions.clone(),
+            self.id_prefix_context()?,
+            immutable,
+        );
         expression.intersect_with(&to_rewrite_revset);
 
         let mut commit_id_iter = expression.evaluate_to_commit_ids().map_err(|e| {
@@ -1153,6 +1159,13 @@ impl WorkspaceCommandHelper {
         Ok(())
     }
 
+    pub fn check_rewritable<'a>(
+        &'a self,
+        commits: impl IntoIterator<Item = &'a CommitId>,
+    ) -> Result<(), CommandError> {
+        self.check_repo_rewritable(self.repo().as_ref(), commits)
+    }
+
     #[instrument(skip_all)]
     fn snapshot_working_copy(&mut self, ui: &mut Ui) -> Result<(), CommandError> {
         let workspace_id = self.workspace_id().to_owned();
@@ -1318,6 +1331,26 @@ See https://github.com/martinvonz/jj/blob/main/docs/working-copy.md#stale-workin
             writeln!(ui.status(), "Rebased {num_rebased} descendant commits")?;
         }
 
+        for (workspace_id, wc_commit_id) in
+            tx.mut_repo().view().wc_commit_ids().clone().iter().sorted()
+        //sorting otherwise non deterministic order (bad for tests)
+        {
+            if self
+                .check_repo_rewritable(tx.repo(), [wc_commit_id])
+                .is_err()
+            {
+                let wc_commit = tx.repo().store().get_commit(wc_commit_id)?;
+                tx.mut_repo()
+                    .check_out(workspace_id.clone(), &self.settings, &wc_commit)?;
+                writeln!(
+                    ui.warning_default(),
+                    "The working-copy commit in workspace '{}' became immutable, so a new commit \
+                     has been created on top of it.",
+                    workspace_id.as_str()
+                )?;
+            }
+        }
+
         let old_repo = tx.base_repo().clone();
 
         let maybe_old_wc_commit = old_repo
@@ -1331,6 +1364,7 @@ See https://github.com/martinvonz/jj/blob/main/docs/working-copy.md#stale-workin
             .get_wc_commit_id(self.workspace_id())
             .map(|commit_id| tx.repo().store().get_commit(commit_id))
             .transpose()?;
+
         if self.working_copy_shared_with_git {
             let git_repo = self.git_backend().unwrap().open_git_repo()?;
             if let Some(wc_commit) = &maybe_new_wc_commit {
@@ -1339,6 +1373,7 @@ See https://github.com/martinvonz/jj/blob/main/docs/working-copy.md#stale-workin
             let failed_branches = git::export_refs(tx.mut_repo())?;
             print_failed_git_export(ui, &failed_branches)?;
         }
+
         self.user_repo = ReadonlyUserRepo::new(tx.commit(description));
         self.report_repo_changes(ui, &old_repo)?;
 
@@ -1350,6 +1385,7 @@ See https://github.com/martinvonz/jj/blob/main/docs/working-copy.md#stale-workin
                 // update it.
             }
         }
+
         let settings = &self.settings;
         if settings.user_name().is_empty() || settings.user_email().is_empty() {
             writeln!(

cli/tests/test_immutable_commits.rs

@@ -109,6 +109,65 @@ fn test_rewrite_immutable_generic() {
     "###);
 }
 
+#[test]
+fn test_new_wc_commit_when_wc_immutable() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init"]);
+    test_env.jj_cmd_ok(test_env.env_root(), &["branch", "create", "main"]);
+    test_env.add_config(r#"revset-aliases."immutable_heads()" = "main""#);
+    test_env.jj_cmd_ok(test_env.env_root(), &["new", "-m=a"]);
+    let (_, stderr) = test_env.jj_cmd_ok(test_env.env_root(), &["branch", "set", "main"]);
+    insta::assert_snapshot!(stderr, @r###"
+Warning: The working-copy commit in workspace 'default' became immutable, so a new commit has been created on top of it.
+Working copy now at: zsuskuln 87e33403 (empty) (no description set)
+Parent commit      : kkmpptxz 7272528e main | (empty) a
+    "###);
+}
+
+#[test]
+fn test_immutable_heads_set_to_working_copy() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init"]);
+    test_env.jj_cmd_ok(test_env.env_root(), &["branch", "create", "main"]);
+    test_env.add_config(r#"revset-aliases."immutable_heads()" = "@""#);
+    let (_, stderr) = test_env.jj_cmd_ok(test_env.env_root(), &["new", "-m=a"]);
+    insta::assert_snapshot!(stderr, @r###"
+Warning: The working-copy commit in workspace 'default' became immutable, so a new commit has been created on top of it.
+Working copy now at: pmmvwywv 09dafa31 (empty) (no description set)
+Parent commit      : kkmpptxz 4963e243 (empty) a
+    "###);
+}
+
+#[test]
+fn test_new_wc_commit_when_wc_immutable_multi_workspace() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init"]);
+    test_env.jj_cmd_ok(test_env.env_root(), &["branch", "create", "main"]);
+    test_env.add_config(r#"revset-aliases."immutable_heads()" = "main""#);
+    test_env.jj_cmd_ok(test_env.env_root(), &["new", "-m=a"]);
+    test_env.jj_cmd_ok(test_env.env_root(), &["workspace", "add", "workspace1"]);
+    let workspace1_envroot = test_env.env_root().join("workspace1");
+    test_env.jj_cmd_ok(workspace1_envroot.as_path(), &["edit", "default@"]);
+    let (_, stderr) = test_env.jj_cmd_ok(test_env.env_root(), &["branch", "set", "main"]);
+    insta::assert_snapshot!(stderr, @r###"
+Warning: The working-copy commit in workspace 'default' became immutable, so a new commit has been created on top of it.
+Warning: The working-copy commit in workspace 'workspace1' became immutable, so a new commit has been created on top of it.
+Working copy now at: royxmykx c37fd624 (empty) (no description set)
+Parent commit      : kkmpptxz ada0ee19 main | a
+    "###);
+    test_env.jj_cmd_ok(workspace1_envroot.as_path(), &["workspace", "update-stale"]);
+    let (stdout, _) = test_env.jj_cmd_ok(workspace1_envroot.as_path(), &["log", "--no-graph"]);
+    insta::assert_snapshot!(stdout, @r###"
+nppvrztz test.user@example.com 2001-02-03 08:05:11 workspace1@ f5e1b845
+(empty) (no description set)
+royxmykx test.user@example.com 2001-02-03 08:05:12 default@ c37fd624
+(empty) (no description set)
+kkmpptxz test.user@example.com 2001-02-03 08:05:12 main ada0ee19
+a
+zzzzzzzz root() 00000000
+        "###);
+}
+
 #[test]
 fn test_rewrite_immutable_commands() {
     let test_env = TestEnvironment::default();