Method collect_commit_oids

atomic-cli/src/commands/git/parallel.rs:2446–2499

Collect commit OIDs in topological order (oldest first).

(
        &self,
        git_repo: &GitRepository,
        branch_name: &str,
    )

    /// Collect commit OIDs in topological order (oldest first).
    fn collect_commit_oids(
        &self,
        git_repo: &GitRepository,
        branch_name: &str,
    ) -> CliResult<Vec<Oid>> {
        let reference = git_repo
            .find_branch(branch_name, git2::BranchType::Local)
            .map_err(|e| CliError::GitError {
                message: format!("Branch '{}' not found: {}", branch_name, e),
            })?;

        let target_oid = reference.get().target().ok_or_else(|| CliError::GitError {
            message: format!("Branch '{}' has no target commit", branch_name),
        })?;

        let mut revwalk = git_repo.revwalk().map_err(|e| CliError::GitError {
            message: format!("Failed to create revwalk: {}", e),
        })?;

        revwalk.push(target_oid).map_err(|e| CliError::GitError {
            message: format!("Failed to push target to revwalk: {}", e),
        })?;

        if self.options.mainline_only {
            revwalk
                .simplify_first_parent()
                .map_err(|e| CliError::GitError {
                    message: format!("Failed to simplify revwalk to first-parent history: {}", e),
                })?;
        }

        // Topological order, oldest first
        revwalk
            .set_sorting(git2::Sort::TOPOLOGICAL | git2::Sort::REVERSE)
            .map_err(|e| CliError::GitError {
                message: format!("Failed to set sorting: {}", e),
            })?;

        let mut oids = Vec::new();
        for oid_result in revwalk {
            let oid = oid_result.map_err(|e| CliError::GitError {
                message: format!("Revwalk error: {}", e),
            })?;

            // Skip already imported commits in incremental mode
            if self.options.incremental && self.options.imported_shas.contains(&oid.to_string()) {
                continue;
            }

            oids.push(oid);
        }

        Ok(oids)
    }

    // ═══════════════════════════════════════════════════════════════════════
    // Phase 1: Parallel Git Parsing