[suggest] change merge strategy： do not check write access if user in merge white list

routers/routes/routes.go

@@ -527,7 +527,6 @@ func RegisterRoutes(m *macaron.Macaron) {
 	reqRepoUncycloWriter := context.RequireRepoWriter(models.UnitTypeUncyclo)
 	reqRepoIssueWriter := context.RequireRepoWriter(models.UnitTypeIssues)
 	reqRepoIssueReader := context.RequireRepoReader(models.UnitTypeIssues)
-	reqRepoPullsWriter := context.RequireRepoWriter(models.UnitTypePullRequests)
 	reqRepoPullsReader := context.RequireRepoReader(models.UnitTypePullRequests)
 	reqRepoIssuesOrPullsWriter := context.RequireRepoWriterOr(models.UnitTypeIssues, models.UnitTypePullRequests)
 	reqRepoIssuesOrPullsReader := context.RequireRepoReaderOr(models.UnitTypeIssues, models.UnitTypePullRequests)
@@ -886,7 +885,7 @@ func RegisterRoutes(m *macaron.Macaron) {
 			m.Get(".diff", repo.DownloadPullDiff)
 			m.Get(".patch", repo.DownloadPullPatch)
 			m.Get("/commits", context.RepoRef(), repo.ViewPullCommits)
-			m.Post("/merge", context.RepoMustNotBeArchived(), reqRepoPullsWriter, bindIgnErr(auth.MergePullRequestForm{}), repo.MergePullRequest)
+			m.Post("/merge", context.RepoMustNotBeArchived(), bindIgnErr(auth.MergePullRequestForm{}), repo.MergePullRequest)
 			m.Post("/update", repo.UpdatePullRequest)
 			m.Post("/cleanup", context.RepoMustNotBeArchived(), context.RepoRef(), repo.CleanUpPullRequest)
 			m.Group("/files", func() {

services/pull/merge.go

@@ -531,16 +531,13 @@ func IsSignedIfRequired(pr *models.PullRequest, doer *models.User) (bool, error)
 
 // IsUserAllowedToMerge check if user is allowed to merge PR with given permissions and branch protections
 func IsUserAllowedToMerge(pr *models.PullRequest, p models.Permission, user *models.User) (bool, error) {
-	if !p.CanWrite(models.UnitTypeCode) {
-		return false, nil
-	}
 
 	err := pr.LoadProtectedBranch()
 	if err != nil {
 		return false, err
 	}
 
-	if pr.ProtectedBranch == nil || pr.ProtectedBranch.IsUserMergeWhitelisted(user.ID) {
+	if (p.CanWrite(models.UnitTypeCode) && pr.ProtectedBranch == nil) || pr.ProtectedBranch.IsUserMergeWhitelisted(user.ID) {
 		return true, nil
 	}