restore: add --restore-descendants flag

CHANGELOG.md

@@ -69,11 +69,9 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 * `jj commit` and `jj describe` now accept `--author` option allowing to quickly change
   author of given commit.
 
-* `jj diffedit` now accepts a `--restore-descendants` flag. When used,
-  descendants of the edited commit will keep their original content.
-
-* `jj abandon` now accepts a `--restore-descendants` flag. When used,
-  descendants of the abandoned commits will keep their original content.
+* `jj diffedit`, `jj abandon`, and `jj restore` now accept a `--restore-descendants`
+  flag. When used, descendants of the edited or deleted commits will keep their original
+  content.
 
 ### Fixed bugs
 

cli/src/commands/restore.rs

@@ -70,6 +70,9 @@ pub(crate) struct RestoreArgs {
     /// the user might not even realize something went wrong.
     #[arg(long, short, hide = true)]
     revision: Option<RevisionArg>,
+    /// Do not modify the content of the children of the rewritten commits
+    #[arg(long)]
+    restore_descendants: bool,
 }
 
 #[instrument(skip_all)]
@@ -116,13 +119,23 @@ pub(crate) fn cmd_restore(
             .write()?;
         // rebase_descendants early; otherwise `new_commit` would always have
         // a conflicted change id at this point.
-        let num_rebased = tx.repo_mut().rebase_descendants(command.settings())?;
+        let (num_rebased, extra_msg) = if args.restore_descendants {
+            (
+                tx.repo_mut().reparent_descendants(command.settings())?,
+                " (while preserving their content)",
+            )
+        } else {
+            (tx.repo_mut().rebase_descendants(command.settings())?, "")
+        };
         if let Some(mut formatter) = ui.status_formatter() {
             write!(formatter, "Created ")?;
             tx.write_commit_summary(formatter.as_mut(), &new_commit)?;
             writeln!(formatter)?;
             if num_rebased > 0 {
-                writeln!(formatter, "Rebased {num_rebased} descendant commits")?;
+                writeln!(
+                    formatter,
+                    "Rebased {num_rebased} descendant commits{extra_msg}"
+                )?;
             }
         }
         tx.finish(ui, format!("restore into commit {}", to_commit.id().hex()))?;

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

@@ -1784,6 +1784,7 @@ See `jj diffedit` if you'd like to restore portions of files rather than entire
    This undoes the changes that can be seen with `jj diff -r REVISION`. If `REVISION` only has a single parent, this option is equivalent to `jj restore --to REVISION --from REVISION-`.
 
    The default behavior of `jj restore` is equivalent to `jj restore --changes-in @`.
+* `--restore-descendants` — Do not modify the content of the children of the rewritten commits
 
 
 

cli/tests/test_restore_command.rs

@@ -261,6 +261,87 @@ fn test_restore_conflicted_merge() {
     "###);
 }
 
+#[test]
+fn test_restore_restore_descendants() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
+    let repo_path = test_env.env_root().join("repo");
+
+    create_commit(&test_env, &repo_path, "base", &[], &[("file", "base\n")]);
+    create_commit(&test_env, &repo_path, "a", &["base"], &[("file", "a\n")]);
+    create_commit(
+        &test_env,
+        &repo_path,
+        "b",
+        &["base"],
+        &[("file", "b\n"), ("file2", "b\n")],
+    );
+    create_commit(
+        &test_env,
+        &repo_path,
+        "ab",
+        &["a", "b"],
+        &[("file", "ab\n")],
+    );
+    // Test the setup
+    insta::assert_snapshot!(get_log_output(&test_env, &repo_path), @r#"
+    @    ab
+    ├─╮
+    │ ○  b
+    ○ │  a
+    ├─╯
+    ○  base
+    ◆
+    "#);
+    insta::assert_snapshot!(
+    std::fs::read_to_string(repo_path.join("file")).unwrap(), @r#"
+    ab
+    "#);
+
+    // Commit "b" was not supposed to modify "file", restore it from its parent
+    // while preserving its child commit content.
+    let (stdout, stderr) = test_env.jj_cmd_ok(
+        &repo_path,
+        &["restore", "-c", "b", "file", "--restore-descendants"],
+    );
+    insta::assert_snapshot!(stdout, @"");
+    insta::assert_snapshot!(stderr, @r#"
+    Created royxmykx 3fd5aa05 b | b
+    Rebased 1 descendant commits (while preserving their content)
+    Working copy now at: vruxwmqv bf5491a0 ab | ab
+    Parent commit      : zsuskuln aa493daf a | a
+    Parent commit      : royxmykx 3fd5aa05 b | b
+    "#);
+
+    // Check that "a", "b", and "ab" have their expected content by diffing them.
+    // "ab" must have kept its content.
+    insta::assert_snapshot!(test_env.jj_cmd_success(&repo_path, &["diff", "--from", "a", "--to", "ab", "--git"]), @r#"
+    diff --git a/file b/file
+    index 7898192261..81bf396956 100644
+    --- a/file
+    +++ b/file
+    @@ -1,1 +1,1 @@
+    -a
+    +ab
+    diff --git a/file2 b/file2
+    new file mode 100644
+    index 0000000000..6178079822
+    --- /dev/null
+    +++ b/file2
+    @@ -1,0 +1,1 @@
+    +b
+    "#);
+    insta::assert_snapshot!(test_env.jj_cmd_success(&repo_path, &["diff", "--from", "b", "--to", "ab", "--git"]), @r#"
+    diff --git a/file b/file
+    index df967b96a5..81bf396956 100644
+    --- a/file
+    +++ b/file
+    @@ -1,1 +1,1 @@
+    -base
+    +ab
+    "#);
+}
+
 fn create_commit(
     test_env: &TestEnvironment,
     repo_path: &Path,