abandon: add --restore-descendants flag

CHANGELOG.md

@@ -72,6 +72,9 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 * `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.
+
 ### Fixed bugs
 
  * Update working copy before reporting changes. This prevents errors during reporting

cli/src/commands/abandon.rs

@@ -43,6 +43,9 @@ pub(crate) struct AbandonArgs {
     /// Ignored (but lets you pass `-r` for consistency with other commands)
     #[arg(short = 'r', hide = true, action = clap::ArgAction::Count)]
     unused_revision: u8,
+    /// Do not modify the content of the children of the abandoned commits
+    #[arg(long)]
+    restore_descendants: bool,
 }
 
 #[instrument(skip_all)]
@@ -66,7 +69,14 @@ pub(crate) fn cmd_abandon(
     for commit in &to_abandon {
         tx.repo_mut().record_abandoned_commit(commit.id().clone());
     }
-    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() {
         if to_abandon.len() == 1 {
@@ -88,7 +98,8 @@ pub(crate) fn cmd_abandon(
         if num_rebased > 0 {
             writeln!(
                 formatter,
-                "Rebased {num_rebased} descendant commits onto parents of abandoned commits"
+                "Rebased {num_rebased} descendant commits{extra_msg} onto parents of abandoned \
+                 commits",
             )?;
         }
     }

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

@@ -207,6 +207,7 @@ If a working-copy commit gets abandoned, it will be given a new, empty commit. T
 ###### **Options:**
 
 * `-s`, `--summary` — Do not print every abandoned commit on a separate line
+* `--restore-descendants` — Do not modify the content of the children of the abandoned commits
 
 
 

cli/tests/test_abandon_command.rs

@@ -364,6 +364,42 @@ fn test_double_abandon() {
     "###);
 }
 
+#[test]
+fn test_abandon_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");
+
+    std::fs::write(repo_path.join("file"), "foo\n").unwrap();
+    test_env.jj_cmd_ok(&repo_path, &["new"]);
+    std::fs::write(repo_path.join("file"), "bar\n").unwrap();
+    test_env.jj_cmd_ok(&repo_path, &["new"]);
+    std::fs::write(repo_path.join("file"), "baz\n").unwrap();
+
+    // Remove the commit containing "bar"
+    let (stdout, stderr) = test_env.jj_cmd_ok(
+        &repo_path,
+        &["abandon", "-r", "@-", "--restore-descendants"],
+    );
+    insta::assert_snapshot!(stdout, @"");
+    insta::assert_snapshot!(stderr, @r#"
+    Abandoned commit rlvkpnrz 225adef1 (no description set)
+    Rebased 1 descendant commits (while preserving their content) onto parents of abandoned commits
+    Working copy now at: kkmpptxz a734deb0 (no description set)
+    Parent commit      : qpvuntsm 485d52a9 (no description set)
+    "#);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "--git"]);
+    insta::assert_snapshot!(stdout, @r#"
+    diff --git a/file b/file
+    index 257cc5642c..76018072e0 100644
+    --- a/file
+    +++ b/file
+    @@ -1,1 +1,1 @@
+    -foo
+    +baz
+    "#);
+}
+
 fn get_log_output(test_env: &TestEnvironment, repo_path: &Path) -> String {
     test_env.jj_cmd_success(
         repo_path,