From 38474a9fb91dbad20a3f5875a62dd075b4524de0 Mon Sep 17 00:00:00 2001
From: Martin von Zweigbergk <martinvonz@google.com>
Date: Sat, 25 Sep 2021 10:11:58 -0700
Subject: [PATCH] cli: remove non-visible heads after every operation

This makes it so that almost every command will remove non-visible
heads. That shouldn't have much visible effect, except that the
`all_heads()` revset will become the same as
`non_obsolete_heads()`.

It will help us remove support for evolution by cleaning up existing
repos. Existing repos (like mine) will lose the unwanted heads (~8.5k
heads in my case), so they don't clutter the repo once evolution is
gone.

This is part of issue #32.
---
 src/commands.rs | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/src/commands.rs b/src/commands.rs
index 08b999a9b..7325beb4a 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -471,11 +471,38 @@ impl RepoCommandHelper {
         if self.auto_update_branches {
             update_branches_after_rewrite(mut_repo);
         }
+        remove_hidden_heads(mut_repo);
         self.repo = tx.commit();
         update_working_copy(ui, &self.repo, &self.repo.working_copy_locked())
     }
 }
 
+fn remove_hidden_heads(mut_repo: &mut MutableRepo) {
+    let mut view = mut_repo.view().store_view().clone();
+    let heads_expression =
+        RevsetExpression::commits(view.head_ids.iter().cloned().collect_vec()).non_obsolete_heads();
+    let public_heads_expression =
+        RevsetExpression::commits(view.public_head_ids.iter().cloned().collect_vec())
+            .non_obsolete_heads();
+    view.head_ids.clear();
+    view.public_head_ids.clear();
+    for index_entry in heads_expression
+        .evaluate(mut_repo.as_repo_ref())
+        .unwrap()
+        .iter()
+    {
+        view.head_ids.insert(index_entry.commit_id());
+    }
+    for index_entry in public_heads_expression
+        .evaluate(mut_repo.as_repo_ref())
+        .unwrap()
+        .iter()
+    {
+        view.public_head_ids.insert(index_entry.commit_id());
+    }
+    mut_repo.set_view(view)
+}
+
 fn rev_arg<'a, 'b>() -> Arg<'a, 'b> {
     Arg::with_name("revision")
         .long("revision")