Hide command line merge instructions when user can't push (#17339)

Hides the command line instructions if the authenticated user can't push to the base branch.
Closes #17121

routers/web/repo/issue.go

@@ -1543,6 +1543,7 @@ func ViewIssue(ctx *context.Context) {
 			ctx.ServerError("LoadProtectedBranch", err)
 			return
 		}
+		ctx.Data["ShowMergeInstructions"] = true
 		if pull.ProtectedBranch != nil {
 			cnt := pull.ProtectedBranch.GetGrantedApprovalsCount(pull)
 			ctx.Data["IsBlockedByApprovals"] = !pull.ProtectedBranch.HasEnoughApprovals(pull)
@@ -1554,6 +1555,7 @@ func ViewIssue(ctx *context.Context) {
 			ctx.Data["ChangedProtectedFiles"] = pull.ChangedProtectedFiles
 			ctx.Data["IsBlockedByChangedProtectedFiles"] = len(pull.ChangedProtectedFiles) != 0
 			ctx.Data["ChangedProtectedFilesNum"] = len(pull.ChangedProtectedFiles)
+			ctx.Data["ShowMergeInstructions"] = pull.ProtectedBranch.CanUserPush(ctx.User.ID)
 		}
 		ctx.Data["WillSign"] = false
 		if ctx.User != nil {

templates/repo/issue/view_content/pull.tmpl

@@ -485,6 +485,7 @@
 									{{end}}
 								</div>
 							</div>
+							{{if .ShowMergeInstructions}}
 								<div class="instruct-toggle ml-3"> {{$.i18n.Tr "repo.pulls.merge_instruction_hint" | Safe}} </div>
 								<div class="instruct-content" style="display:none">
 									<div class="ui divider"></div>
@@ -504,6 +505,7 @@
 										<div>git push origin {{.Issue.PullRequest.BaseBranch}}</div>
 									</div>
 								</div>
+							{{end}}
 						{{else}}
 							<div class="ui divider"></div>
 							<div class="item text red">