From f43f0d24b81fb2450f00f476206429b5d1641771 Mon Sep 17 00:00:00 2001
From: Yuya Nishihara <yuya@tcha.org>
Date: Thu, 6 Apr 2023 12:49:29 +0900
Subject: [PATCH] revset: resolve candidates of children set prior to
 evaluation

---
 lib/src/default_revset_engine.rs | 10 ++++++----
 lib/src/revset.rs                | 12 ++++++++----
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/lib/src/default_revset_engine.rs b/lib/src/default_revset_engine.rs
index 988d6d935..24d2007ab 100644
--- a/lib/src/default_revset_engine.rs
+++ b/lib/src/default_revset_engine.rs
@@ -588,10 +588,11 @@ impl<'index, 'heads> EvaluationContext<'index, 'heads> {
             ResolvedExpression::Commits(commit_ids) => {
                 Ok(Box::new(self.revset_for_commit_ids(commit_ids)))
             }
-            ResolvedExpression::Children(roots) => {
+            ResolvedExpression::Children { roots, heads } => {
                 let root_set = self.evaluate(roots)?;
-                let head_set = self.revset_for_commit_ids(self.visible_heads);
-                let (walk, root_positions) = self.walk_ancestors_until_roots(&*root_set, &head_set);
+                let head_set = self.evaluate(heads)?;
+                let (walk, root_positions) =
+                    self.walk_ancestors_until_roots(&*root_set, &*head_set);
                 let roots: HashSet<_> = root_positions.into_iter().collect();
                 let candidates = Box::new(RevWalkRevset { walk });
                 let predicate = pure_predicate_fn(move |entry| {
@@ -600,7 +601,8 @@ impl<'index, 'heads> EvaluationContext<'index, 'heads> {
                         .iter()
                         .any(|parent_pos| roots.contains(parent_pos))
                 });
-                // TODO: ToPredicateFn version can be optimized to only test the predicate()
+                // TODO: Suppose heads include all visible heads, ToPredicateFn version can be
+                // optimized to only test the predicate()
                 Ok(Box::new(FilterRevset {
                     candidates,
                     predicate,
diff --git a/lib/src/revset.rs b/lib/src/revset.rs
index c324b7751..f051fb067 100644
--- a/lib/src/revset.rs
+++ b/lib/src/revset.rs
@@ -462,7 +462,10 @@ pub enum ResolvedPredicateExpression {
 pub enum ResolvedExpression {
     All, // TODO: should be substituted at resolve_visibility()
     Commits(Vec<CommitId>),
-    Children(Box<ResolvedExpression>), // TODO: add heads: VisibleHeads
+    Children {
+        roots: Box<ResolvedExpression>,
+        heads: Box<ResolvedExpression>,
+    },
     Ancestors {
         heads: Box<ResolvedExpression>,
         generation: Range<u32>,
@@ -1823,9 +1826,10 @@ impl VisibilityResolutionContext {
             RevsetExpression::CommitRef(_) => {
                 panic!("Expression '{expression:?}' should have been resolved by caller");
             }
-            RevsetExpression::Children(roots) => {
-                ResolvedExpression::Children(self.resolve(roots).into())
-            }
+            RevsetExpression::Children(roots) => ResolvedExpression::Children {
+                roots: self.resolve(roots).into(),
+                heads: self.resolve_visible_heads().into(),
+            },
             RevsetExpression::Ancestors { heads, generation } => ResolvedExpression::Ancestors {
                 heads: self.resolve(heads).into(),
                 generation: generation.clone(),