Improve behavior of "Fork" button

models/repo.go

@@ -773,6 +773,35 @@ func (repo *Repository) CanUserFork(user *User) (bool, error) {
 	return false, nil
 }
 
+// GetForksByUserAndOwnedOrgs return forked repos of the user and owned orgs
+func (repo *Repository) GetForksByUserAndOwnedOrgs(user *User) ([]*Repository, error) {
+	var repoList []*Repository
+	if user == nil {
+		return repoList, nil
+	}
+	var forkedRepo *Repository
+	forkedRepo, err := repo.GetUserFork(user.ID)
+	if err != nil {
+		return repoList, err
+	}
+	if forkedRepo != nil {
+		repoList = append(repoList, forkedRepo)
+	}
+	if err := user.GetOwnedOrganizations(); err != nil {
+		return repoList, err
+	}
+	for _, org := range user.OwnedOrgs {
+		forkedRepo, err := repo.GetUserFork(org.ID)
+		if err != nil {
+			return repoList, err
+		}
+		if forkedRepo != nil {
+			repoList = append(repoList, forkedRepo)
+		}
+	}
+	return repoList, nil
+}
+
 // CanUserDelete returns true if user could delete the repository
 func (repo *Repository) CanUserDelete(user *User) (bool, error) {
 	if user.IsAdmin || user.ID == repo.OwnerID {

modules/context/repo.go

@@ -489,10 +489,24 @@ func RepoAssignment(ctx *Context) (cancel context.CancelFunc) {
 	ctx.Data["CanWriteIssues"] = ctx.Repo.CanWrite(models.UnitTypeIssues)
 	ctx.Data["CanWritePulls"] = ctx.Repo.CanWrite(models.UnitTypePullRequests)
 
-	if ctx.Data["CanSignedUserFork"], err = ctx.Repo.Repository.CanUserFork(ctx.User); err != nil {
+	canSignedUserFork, err := ctx.Repo.Repository.CanUserFork(ctx.User)
+	if err != nil {
 		ctx.ServerError("CanUserFork", err)
 		return
 	}
+	ctx.Data["CanSignedUserFork"] = canSignedUserFork
+
+	userAndOrgForks, err := ctx.Repo.Repository.GetForksByUserAndOwnedOrgs(ctx.User)
+	if err != nil {
+		ctx.ServerError("GetForksByUserAndOwnedOrgs", err)
+		return
+	}
+	ctx.Data["UserAndOrgForks"] = userAndOrgForks
+
+	// canSignedUserFork is true if the current user doesn't have a fork of this repo yet or
+	// if he owns an org that doesn't have a fork of this repo yet
+	// If multiple forks are available or if the user can fork to another account, but there is already a fork: open selection dialog
+	ctx.Data["ShowForkModal"] = len(userAndOrgForks) > 1 || (canSignedUserFork && len(userAndOrgForks) > 0)
 
 	ctx.Data["DisableSSH"] = setting.SSH.Disabled
 	ctx.Data["ExposeAnonSSH"] = setting.SSH.ExposeAnonymous

options/locale/locale_en-US.ini

@@ -767,6 +767,8 @@ visibility_fork_helper = (Changing this will affect all forks.)
 clone_helper = Need help cloning? Visit <a target="_blank" rel="noopener noreferrer" href="%s">Help</a>.
 fork_repo = Fork Repository
 fork_from = Fork From
+already_forked = You've already forked %s.
+fork_to_different_account = Fork to a different account
 fork_visibility_helper = The visibility of a forked repository cannot be changed.
 use_template = Use this template
 clone_in_vsc = Clone in VS Code

templates/repo/header.tmpl

@@ -85,10 +85,42 @@
 						</form>
 					{{end}}
 					{{if and (not .IsEmpty) ($.Permission.CanRead $.UnitTypeCode)}}
-						<div class="ui labeled button{{if not $.CanSignedUserFork}} poping up disabled{{end}}"{{if and (not $.CanSignedUserFork) $.IsSigned}} data-content="{{$.i18n.Tr "repo.fork_from_self"}}" {{else if not $.IsSigned}} data-content="{{$.i18n.Tr "repo.fork_guest_user"}}"{{end}} data-position="top center" data-variation="tiny" tabindex="0">
-							<a class="ui compact small basic button"{{if $.CanSignedUserFork}} href="{{AppSubUrl}}/repo/fork/{{.ID}}"{{end}}>
+						<div class="ui labeled button{{if or (not $.IsSigned)}} poping up disabled{{end}}" {{if not $.IsSigned}} data-content="{{$.i18n.Tr "repo.fork_guest_user"}}"{{end}} data-position="top center" data-variation="tiny" tabindex="0">
+							<a class="ui compact{{if $.ShowForkModal}} show-modal{{end}} small basic button"
+								{{if not $.CanSignedUserFork}}
+									{{if gt (len $.UserAndOrgForks) 1}}
+										data-modal="#fork-repo-modal"
+									{{else}}
+										href="{{AppSubUrl}}/{{(index $.UserAndOrgForks 0).FullName}}"
+									{{end}}
+								{{else if eq (len $.UserAndOrgForks) 0}}
+									href="{{AppSubUrl}}/repo/fork/{{.ID}}"
+								{{else}}
+									data-modal="#fork-repo-modal"
+								{{end}}
+							>
 								{{svg "octicon-repo-forked"}}{{$.i18n.Tr "repo.fork"}}
 							</a>
+							<div class="ui small modal" id="fork-repo-modal">
+								<div class="header">
+									{{$.i18n.Tr "repo.already_forked" .FullName}}
+								</div>
+								<div class="content">
+									{{range $.UserAndOrgForks}}
+										<div class="text left">
+											<a href="{{.Link}}">
+												{{svg "octicon-repo-forked"}}{{.FullName}}
+											</a>
+										</div>
+									{{end}}
+									{{if $.CanSignedUserFork}}
+									<br><br>
+									<a class="ui compact small button right actions" style="margin-bottom: 20px;" href="{{AppSubUrl}}/repo/fork/{{.ID}}">
+										{{$.i18n.Tr "repo.fork_to_different_account"}}
+									</a>
+									{{end}}
+								</div>
+							</div>
 							<a class="ui basic label" href="{{.Link}}/forks">
 								{{CountFmt .NumForks}}
 							</a>

web_src/less/_repository.less

@@ -2729,7 +2729,8 @@
 #delete-repo-modal,
 #delete-wiki-modal,
 #convert-fork-repo-modal,
-#convert-mirror-repo-modal {
+#convert-mirror-repo-modal,
+#fork-repo-modal {
   .ui.message {
     width: 100% !important;
   }