Add an experimental feature that puts the git commit in the mercurial…

… changeset `extras`
glandium · Jun 28, 2024 · 8be6fd0 · 8be6fd0
1 parent 6679c5f
commit 8be6fd0
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Showing 3 changed files with 42 additions and 2 deletions.
diff --git a/src/main.rs b/src/main.rs
@@ -4864,6 +4864,8 @@ pub fn has_compat(c: Compat) -> bool {
 bitflags! {
     pub struct Experiments: i32 {
         const MERGE = 0x1;
+        // Add git commit as extra metadata in mercurial changesets.
+        const GIT_COMMIT = 0x2;
     }
 }
 pub struct AllExperiments {
@@ -4883,6 +4885,9 @@ static EXPERIMENTS: Lazy<AllExperiments> = Lazy::new(|| {
                 b"merge" => {
                     flags |= Experiments::MERGE;
                 }
+                b"git_commit" => {
+                    flags |= Experiments::GIT_COMMIT;
+                }
                 s if s.starts_with(b"similarity") => {
                     if let Some(value) = s[b"similarity".len()..].strip_prefix(b"=") {
                         match u8::from_bytes(value) {

diff --git a/src/store.rs b/src/store.rs
@@ -58,7 +58,7 @@ use crate::util::{
     SliceExt, ToBoxed, Transpose,
 };
 use crate::xdiff::{apply, textdiff, PatchInfo};
-use crate::{check_enabled, has_compat, Checks, Compat};
+use crate::{check_enabled, experiment, has_compat, Checks, Compat, Experiments};
 
 pub const REFS_PREFIX: &str = "refs/cinnabar/";
 pub const REPLACE_REFS_PREFIX: &str = "refs/cinnabar/replace/";
@@ -1873,9 +1873,17 @@ pub fn create_changeset(
             .extra()
             .and_then(|e| e.get(b"branch").map(ToBoxed::to_boxed))
     });
+    let mut extra = None;
     if let Some(branch) = &branch {
-        let mut extra = ChangesetExtra::new();
+        let extra = extra.get_or_insert_with(ChangesetExtra::new);
         extra.set(b"branch", branch);
+    }
+    let git_commit_extra = experiment(Experiments::GIT_COMMIT).then(|| commit_id.to_string());
+    if let Some(git_commit_extra) = &git_commit_extra {
+        let extra = extra.get_or_insert_with(ChangesetExtra::new);
+        extra.set(b"git_commit", git_commit_extra.as_bytes());
+    }
+    if let Some(extra) = extra {
         let mut buf = Vec::new();
         extra.dump_into(&mut buf);
         cs_metadata.extra = Some(buf.into_boxed_slice());

diff --git a/tests/push.t b/tests/push.t
@@ -365,3 +365,30 @@ In that corner case, we don't store metadata.
 
   $ git -C uvw-git cinnabar rollback --candidates
   2836e453f32b1ecccd3acca412f75b07c88176bf (current)
+
+  $ rm -rf $REPO/.hg
+  $ hg init $REPO
+  $ git -C abc-git cinnabar rollback 0000000000000000000000000000000000000000
+  $ git -C abc-git push origin 8b86a58578d5270969543e287634e3a2f122a338:refs/heads/branches/default/tip
+  remote: adding changesets
+  remote: adding manifests
+  remote: adding file changes
+  remote: added 1 changesets with 1 changes to 1 files
+  To hg::.*/push.t/repo (re)
+   * [new branch]      8b86a58578d5270969543e287634e3a2f122a338 -> branches/default/tip
+
+  $ git -c cinnabar.experiments=git_commit -C abc-git push origin 687e015f9f646bb19797d991f2f53087297fbe14:branches/default/tip
+  remote: adding changesets
+  remote: adding manifests
+  remote: adding file changes
+  remote: added 2 changesets with 2 changes to 2 files
+  To hg::.*/push.t/repo (re)
+     8b86a58..687e015  687e015f9f646bb19797d991f2f53087297fbe14 -> branches/default/tip
+
+  $ hg -R $REPO log -G --template '{node} {branch} {desc} {extras.git_commit}'
+  o  c70941aaa15aa6e5feae28164438f13dc3cd7b8e default c 687e015f9f646bb19797d991f2f53087297fbe14
+  |
+  o  29872b591f8d41c613bbfad38722824ab0457f17 default b d04f6df4abe2870ceb759263ee6aaa9241c4f93c
+  |
+  o  f92470d7f6966a39dfbced6a525fe81ebf5c37b9 default a
+