Add ref issue when creating pull request from issue

routers/web/repo/compare.go

@@ -845,6 +845,21 @@ func CompareDiff(ctx *context.Context) {
 		ctx.Data["AllowMaintainerEdit"] = false
 	}
 
+	refIssueIndex := ctx.FormInt64("ref_issue_index")
+	if refIssueIndex > 0 {
+		refIssue, err := issues_model.GetIssueByIndex(ctx, ctx.Repo.Repository.ID, refIssueIndex)
+		if err != nil {
+			ctx.Flash.Warning(ctx.Tr("repo.issues.pr.not_exist_issue"), true)
+		} else {
+			keyword := "Resolve"
+			if len(setting.Repository.PullRequest.CloseKeywords) > 0 {
+				keyword = setting.Repository.PullRequest.CloseKeywords[0]
+			}
+			ctx.Data["TitleQuery"] = fmt.Sprintf("%s %s", keyword, refIssue.Title)
+			ctx.Data["BodyQuery"] = fmt.Sprintf("%s #%d", keyword, refIssueIndex)
+		}
+	}
+
 	ctx.HTML(http.StatusOK, tplCompare)
 }