absorb: print status if source commit still contains diffs

Closes #5362

cli/src/commands/absorb.rs

@@ -16,6 +16,7 @@ use clap_complete::ArgValueCandidates;
 use jj_lib::absorb::absorb_hunks;
 use jj_lib::absorb::split_hunks_to_trees;
 use jj_lib::absorb::AbsorbSource;
+use jj_lib::matchers::EverythingMatcher;
 use pollster::FutureExt as _;
 use tracing::instrument;
 
@@ -23,6 +24,7 @@ use crate::cli_util::CommandHelper;
 use crate::cli_util::RevisionArg;
 use crate::command_error::CommandError;
 use crate::complete;
+use crate::diff_util::DiffFormat;
 use crate::ui::Ui;
 
 /// Move changes from a revision into the stack of mutable revisions
@@ -119,5 +121,18 @@ pub(crate) fn cmd_absorb(
             stats.rewritten_destinations.len()
         ),
     )?;
+
+    if let Some(mut formatter) = ui.status_formatter() {
+        if let Some(commit) = &stats.rewritten_source {
+            let repo = workspace_command.repo().as_ref();
+            if !commit.is_empty(repo)? {
+                writeln!(formatter, "Remaining changes:")?;
+                let diff_renderer = workspace_command.diff_renderer(vec![DiffFormat::Summary]);
+                let matcher = &EverythingMatcher; // also print excluded paths
+                let width = ui.term_width();
+                diff_renderer.show_patch(ui, formatter.as_mut(), commit, matcher, width)?;
+            }
+        }
+    }
     Ok(())
 }

cli/tests/test_absorb_command.rs

@@ -480,6 +480,8 @@ fn test_absorb_file_mode() {
     Rebased 1 descendant commits.
     Working copy now at: zsuskuln 77de368e (no description set)
     Parent commit      : qpvuntsm 991365da 1
+    Remaining changes:
+    M file1
     ");
 
     insta::assert_snapshot!(get_diffs(&test_env, &repo_path, "mutable()"), @r"
@@ -521,6 +523,8 @@ fn test_absorb_from_into() {
     Rebased 1 descendant commits.
     Working copy now at: zsuskuln d5424357 (no description set)
     Parent commit      : kkmpptxz 91df4543 2
+    Remaining changes:
+    M file1
     ");
 
     insta::assert_snapshot!(get_diffs(&test_env, &repo_path, "@-::"), @r"
@@ -623,6 +627,8 @@ fn test_absorb_paths() {
     Rebased 1 descendant commits.
     Working copy now at: kkmpptxz c6f31836 (no description set)
     Parent commit      : qpvuntsm ae044adb 1
+    Remaining changes:
+    M file2
     ");
 
     insta::assert_snapshot!(get_diffs(&test_env, &repo_path, "mutable()"), @r"
@@ -677,6 +683,8 @@ fn test_absorb_immutable() {
     Rebased 1 descendant commits.
     Working copy now at: mzvwutvl 3021153d (no description set)
     Parent commit      : kkmpptxz d80e3c2a 2
+    Remaining changes:
+    M file1
     ");
 
     // Immutable revisions shouldn't be rewritten

lib/src/absorb.rs

@@ -271,6 +271,9 @@ fn combine_texts(text1: &[u8], text2: &[u8], selected_ranges: &[SelectedRange])
 /// Describes changes made by [`absorb_hunks()`].
 #[derive(Clone, Debug)]
 pub struct AbsorbStats {
+    /// Rewritten source commit which the absorbed hunks were removed, or `None`
+    /// if the source commit was abandoned or no hunks were moved.
+    pub rewritten_source: Option<Commit>,
     /// Rewritten commits which the source hunks were absorbed into, in forward
     /// topological order.
     pub rewritten_destinations: Vec<Commit>,
@@ -287,6 +290,7 @@ pub fn absorb_hunks(
     mut selected_trees: HashMap<CommitId, MergedTreeBuilder>,
 ) -> BackendResult<AbsorbStats> {
     let store = repo.store().clone();
+    let mut rewritten_source = None;
     let mut rewritten_destinations = Vec::new();
     let mut num_rebased = 0;
     // Rewrite commits in topological order so that descendant commits wouldn't
@@ -298,7 +302,7 @@ pub fn absorb_hunks(
             if commit_builder.is_discardable()? {
                 commit_builder.abandon();
             } else {
-                commit_builder.write()?;
+                rewritten_source = Some(commit_builder.write()?);
                 num_rebased += 1;
             }
             return Ok(());
@@ -324,6 +328,7 @@ pub fn absorb_hunks(
         Ok(())
     })?;
     Ok(AbsorbStats {
+        rewritten_source,
         rewritten_destinations,
         num_rebased,
     })