If a repository return no commitstatus, then still cache it but not query it from database (go-gitea#30700)

The previous repository default branch commit status cache will only
store if the commit status has value. So the repository which have no
any commit status will always be fetched from database.

This PR will store the empty state of commit status of a repository into
cache because the cache will be updated once there is a commit status
stored.

Author: lunny

services/repository/commitstatus/commitstatus.go

@@ -39,12 +39,10 @@ func getCommitStatusCache(repoID int64, branchName string) *commitStatusCacheVal
 	if ok && statusStr != "" {
 		var cv commitStatusCacheValue
 		err := json.Unmarshal([]byte(statusStr), &cv)
-		if err == nil && cv.State != "" {
+		if err == nil {
 			return &cv
 		}
-		if err != nil {
-			log.Warn("getCommitStatusCache: json.Unmarshal failed: %v", err)
-		}
+		log.Warn("getCommitStatusCache: json.Unmarshal failed: %v", err)
 	}
 	return nil
 }
@@ -126,15 +124,22 @@ func CreateCommitStatus(ctx context.Context, repo *repo_model.Repository, creato
 // FindReposLastestCommitStatuses loading repository default branch latest combinded commit status with cache
 func FindReposLastestCommitStatuses(ctx context.Context, repos []*repo_model.Repository) ([]*git_model.CommitStatus, error) {
 	results := make([]*git_model.CommitStatus, len(repos))
+	allCached := true
 	for i, repo := range repos {
 		if cv := getCommitStatusCache(repo.ID, repo.DefaultBranch); cv != nil {
 			results[i] = &git_model.CommitStatus{
 				State:     api.CommitStatusState(cv.State),
 				TargetURL: cv.TargetURL,
 			}
+		} else {
+			allCached = false
 		}
 	}
 
+	if allCached {
+		return results, nil
+	}
+
 	// collect the latest commit of each repo
 	// at most there are dozens of repos (limited by MaxResponseItems), so it's not a big problem at the moment
 	repoBranchNames := make(map[int64]string, len(repos))
@@ -158,7 +163,7 @@ func FindReposLastestCommitStatuses(ctx context.Context, repos []*repo_model.Rep
 	for i, repo := range repos {
 		if results[i] == nil {
 			results[i] = git_model.CalcCommitStatus(repoToItsLatestCommitStatuses[repo.ID])
-			if results[i].State != "" {
+			if results[i] != nil {
 				if err := updateCommitStatusCache(repo.ID, repo.DefaultBranch, results[i].State, results[i].TargetURL); err != nil {
 					log.Error("updateCommitStatusCache[%d:%s] failed: %v", repo.ID, repo.DefaultBranch, err)
 				}