git_fetch: when removing a remote branch, remove git ref as well

CHANGELOG.md

@@ -34,6 +34,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Fixed a bug that could get partially resolved conflicts to be interpreted
   incorrectly.
 
+* `jj git fetch`: when re-adding a remote repository that had been previously
+  removed, in some situations the remote branches were not recreated.
+
 ## [0.7.0] - 2023-02-16
 
 ### Breaking changes

src/commands/git.rs

@@ -192,12 +192,22 @@ fn cmd_git_remote_remove(
             branches_to_delete.push(branch.clone());
         }
     }
-    if !branches_to_delete.is_empty() {
+    let prefix = format!("refs/remotes/{}/", args.remote);
+    let git_refs_to_delete = repo
+        .view()
+        .git_refs()
+        .keys()
+        .filter_map(|r| r.starts_with(&prefix).then(|| r.clone()))
+        .collect_vec();
+    if !branches_to_delete.is_empty() || !git_refs_to_delete.is_empty() {
         let mut tx =
             workspace_command.start_transaction(&format!("remove git remote {}", &args.remote));
         for branch in branches_to_delete {
             tx.mut_repo().remove_remote_branch(&branch, &args.remote);
         }
+        for git_ref in git_refs_to_delete {
+            tx.mut_repo().remove_git_ref(&git_ref);
+        }
         tx.finish(ui)?;
     }
     Ok(())

tests/test_git_fetch.rs

@@ -665,3 +665,43 @@ fn test_git_fetch_undo() {
     o  000000000000
     "###);
 }
+
+#[test]
+fn test_git_fetch_remove_fetch() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+    add_git_remote(&test_env, &repo_path, "origin");
+
+    test_env.jj_cmd_success(&repo_path, &["branch", "set", "origin"]);
+    insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
+    origin: 230dd059e1b0 (no description set)
+    "###);
+
+    test_env.jj_cmd_success(&repo_path, &["git", "fetch"]);
+    insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
+    origin (conflicted):
+      + 230dd059e1b0 (no description set)
+      + ffecd2d67827 message
+      @origin (behind by 1 commits): ffecd2d67827 message
+    "###);
+
+    test_env.jj_cmd_success(&repo_path, &["git", "remote", "remove", "origin"]);
+    insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
+    origin (conflicted):
+      + 230dd059e1b0 (no description set)
+      + ffecd2d67827 message
+    "###);
+
+    test_env.jj_cmd_success(&repo_path, &["git", "remote", "add", "origin", "../origin"]);
+
+    // Check that origin@origin is properly recreated
+    let stdout = test_env.jj_cmd_success(&repo_path, &["git", "fetch"]);
+    insta::assert_snapshot!(stdout, @"");
+    insta::assert_snapshot!(get_branch_output(&test_env, &repo_path), @r###"
+    origin (conflicted):
+      + 230dd059e1b0 (no description set)
+      + ffecd2d67827 message
+      @origin (behind by 1 commits): ffecd2d67827 message
+    "###);
+}