chore: initialize Gitea v1.27.2 fork

Includes direct password setup links in registration emails.

Assisted-by: Codex:GPT-5

models/renderhelper/commit_checker.go

@@ -0,0 +1,57 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package renderhelper
+
+import (
+	"context"
+	"io"
+
+	repo_model "gitea.dev/models/repo"
+	"gitea.dev/modules/git"
+	"gitea.dev/modules/gitrepo"
+	"gitea.dev/modules/log"
+)
+
+type commitChecker struct {
+	ctx          context.Context
+	commitCache  map[string]bool
+	repoOptional *repo_model.Repository
+
+	gitRepo       *git.Repository
+	gitRepoCloser io.Closer
+}
+
+func newCommitChecker(ctx context.Context, repo *repo_model.Repository) *commitChecker {
+	return &commitChecker{ctx: ctx, commitCache: make(map[string]bool), repoOptional: repo}
+}
+
+func (c *commitChecker) Close() error {
+	if c.gitRepoCloser != nil {
+		return c.gitRepoCloser.Close()
+	}
+	return nil
+}
+
+func (c *commitChecker) IsCommitIDExisting(commitID string) bool {
+	if c.repoOptional == nil {
+		return false
+	}
+	exist, inCache := c.commitCache[commitID]
+	if inCache {
+		return exist
+	}
+
+	if c.gitRepo == nil {
+		r, closer, err := gitrepo.RepositoryFromContextOrOpen(c.ctx, c.repoOptional)
+		if err != nil {
+			log.Error("unable to open repository: %s Error: %v", gitrepo.RepoGitURL(c.repoOptional), err)
+			return false
+		}
+		c.gitRepo, c.gitRepoCloser = r, closer
+	}
+
+	exist = c.gitRepo.IsReferenceExist(commitID) // Don't use IsObjectExist since it doesn't support short hashes with gogit edition.
+	c.commitCache[commitID] = exist
+	return exist
+}