cli: add global --ignore-immutable

Closes #3576

CHANGELOG.md

@@ -50,6 +50,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * You can check whether Watchman fsmonitor is enabled or installed with the new
   `jj debug watchman status` command.
 
+* A new global flag `--ignore-immutable` lets you rewrite immutable commits.
+
 ### Fixed bugs
 
 * Revsets now support `\`-escapes in string literal.

cli/src/cli_util.rs

@@ -1065,6 +1065,17 @@ impl WorkspaceCommandHelper {
         &self,
         commits: impl IntoIterator<Item = &'a CommitId>,
     ) -> Result<(), CommandError> {
+        if self.global_args.ignore_immutable {
+            let root_id = self.repo().store().root_commit_id();
+            return if commits.into_iter().contains(root_id) {
+                Err(user_error(format!(
+                    "The root commit {} is immutable",
+                    short_commit_hash(root_id),
+                )))
+            } else {
+                Ok(())
+            };
+        }
         let to_rewrite_revset =
             RevsetExpression::commits(commits.into_iter().cloned().collect_vec());
         let immutable = revset_util::parse_immutable_expression(&self.revset_parse_context())
@@ -2330,6 +2341,16 @@ pub struct GlobalArgs {
     /// implies `--ignore-working-copy`.
     #[arg(long, global = true)]
     pub ignore_working_copy: bool,
+    /// Don't prevent rewriting immutable commits
+    ///
+    /// By default, Jujutsu prevents rewriting commits in the configured set of
+    /// immutable commits. This option disables that check and lets you rewrite
+    /// any commit but the root commit.
+    ///
+    /// This option only affects the check. It does not affect the
+    /// `immutable_heads()` revset or the `immutable` template keyword.
+    #[arg(long, global = true)]
+    pub ignore_immutable: bool,
     /// Operation to load the repo at
     ///
     /// Operation to load the repo at. By default, Jujutsu loads the repo at the

cli/tests/cli-reference@.md.snap

@@ -153,6 +153,10 @@ To get started, see the tutorial at https://github.com/martinvonz/jj/blob/main/d
 
   Possible values: `true`, `false`
 
+* `--ignore-immutable` — Don't prevent rewriting immutable commits
+
+  Possible values: `true`, `false`
+
 * `--at-operation <AT_OPERATION>` — Operation to load the repo at
 
   Default value: `@`

cli/tests/test_global_opts.rs

@@ -592,6 +592,7 @@ fn test_help() {
     Global Options:
       -R, --repository <REPOSITORY>      Path to repository to operate on
           --ignore-working-copy          Don't snapshot the working copy, and don't update it
+          --ignore-immutable             Don't prevent rewriting immutable commits
           --at-operation <AT_OPERATION>  Operation to load the repo at [default: @] [aliases: at-op]
           --debug                        Enable debug logging
           --color <WHEN>                 When to colorize output (always, never, auto)

cli/tests/test_immutable_commits.rs

@@ -67,6 +67,22 @@ fn test_rewrite_immutable_generic() {
     For help, see https://github.com/martinvonz/jj/blob/main/docs/config.md.
     "###);
 
+    // Can use --ignore-immutable to override
+    test_env.add_config(r#"revset-aliases."immutable_heads()" = "main""#);
+    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["--ignore-immutable", "edit", "main"]);
+    insta::assert_snapshot!(stdout, @r###"
+    "###);
+    insta::assert_snapshot!(stderr, @r###"
+    Working copy now at: kkmpptxz c8d4c7ca main | b
+    Parent commit      : qpvuntsm 46a8dc51 a
+    Added 0 files, modified 1 files, removed 0 files
+    "###);
+    // ... but not the root commit
+    let stderr = test_env.jj_cmd_failure(&repo_path, &["--ignore-immutable", "edit", "root()"]);
+    insta::assert_snapshot!(stderr, @r###"
+    Error: The root commit 000000000000 is immutable
+    "###);
+
     // Mutating the repo works if ref is wrapped in present()
     test_env.add_config(
         r#"revset-aliases."immutable_heads()" = "present(branch_that_does_not_exist)""#,
@@ -75,9 +91,8 @@ fn test_rewrite_immutable_generic() {
     insta::assert_snapshot!(stdout, @r###"
     "###);
     insta::assert_snapshot!(stderr, @r###"
-    Working copy now at: kpqxywon dbce15b4 (empty) (no description set)
+    Working copy now at: wqnwkozp de8b93b4 (empty) (no description set)
     Parent commit      : kkmpptxz c8d4c7ca main | b
-    Added 0 files, modified 1 files, removed 0 files
     "###);
 
     // Error if we redefine immutable_heads() with an argument