Implement Issue Config (#20956)

Closes #20955

This PR adds the possibility to disable blank Issues, when the Repo has
templates. This can be done by creating the file
`.gitea/issue_config.yaml` with the content `blank_issues_enabled` in
the Repo.

routers/api/v1/api.go

@@ -1169,6 +1169,8 @@ func Routes(ctx gocontext.Context) *web.Route {
 					}, reqAdmin())
 				}, reqAnyRepoReader())
 				m.Get("/issue_templates", context.ReferencesGitRepo(), repo.GetIssueTemplates)
+				m.Get("/issue_config", context.ReferencesGitRepo(), repo.GetIssueConfig)
+				m.Get("/issue_config/validate", context.ReferencesGitRepo(), repo.ValidateIssueConfig)
 				m.Get("/languages", reqRepoReader(unit.TypeCode), repo.GetLanguages)
 			}, repoAssignment())
 		})

routers/api/v1/repo/repo.go

@@ -1144,3 +1144,58 @@ func GetIssueTemplates(ctx *context.APIContext) {
 
 	ctx.JSON(http.StatusOK, ctx.IssueTemplatesFromDefaultBranch())
 }
+
+// GetIssueConfig returns the issue config for a repo
+func GetIssueConfig(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/issue_config repository repoGetIssueConfig
+	// ---
+	// summary: Returns the issue config for a repo
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/RepoIssueConfig"
+	issueConfig, _ := ctx.IssueConfigFromDefaultBranch()
+	ctx.JSON(http.StatusOK, issueConfig)
+}
+
+// ValidateIssueConfig returns validation errors for the issue config
+func ValidateIssueConfig(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/issue_config/validate repository repoValidateIssueConfig
+	// ---
+	// summary: Returns the validation information for a issue config
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/RepoIssueConfigValidation"
+	_, err := ctx.IssueConfigFromDefaultBranch()
+
+	if err == nil {
+		ctx.JSON(http.StatusOK, api.IssueConfigValidation{Valid: true, Message: ""})
+	} else {
+		ctx.JSON(http.StatusOK, api.IssueConfigValidation{Valid: false, Message: err.Error()})
+	}
+}

routers/api/v1/swagger/repo.go

@@ -386,3 +386,17 @@ type swaggerRepoCollaboratorPermission struct {
 	// in:body
 	Body api.RepoCollaboratorPermission `json:"body"`
 }
+
+// RepoIssueConfig
+// swagger:response RepoIssueConfig
+type swaggerRepoIssueConfig struct {
+	// in:body
+	Body api.IssueConfig `json:"body"`
+}
+
+// RepoIssueConfigValidation
+// swagger:response RepoIssueConfigValidation
+type swaggerRepoIssueConfigValidation struct {
+	// in:body
+	Body api.IssueConfigValidation `json:"body"`
+}

routers/web/repo/issue.go

@@ -435,7 +435,7 @@ func Issues(ctx *context.Context) {
 		}
 		ctx.Data["Title"] = ctx.Tr("repo.issues")
 		ctx.Data["PageIsIssueList"] = true
-		ctx.Data["NewIssueChooseTemplate"] = len(ctx.IssueTemplatesFromDefaultBranch()) > 0
+		ctx.Data["NewIssueChooseTemplate"] = ctx.HasIssueTemplatesOrContactLinks()
 	}
 
 	issues(ctx, ctx.FormInt64("milestone"), ctx.FormInt64("project"), util.OptionalBoolOf(isPullList))
@@ -848,7 +848,7 @@ func setTemplateIfExists(ctx *context.Context, ctxDataKey string, possibleFiles
 func NewIssue(ctx *context.Context) {
 	ctx.Data["Title"] = ctx.Tr("repo.issues.new")
 	ctx.Data["PageIsIssueList"] = true
-	ctx.Data["NewIssueChooseTemplate"] = len(ctx.IssueTemplatesFromDefaultBranch()) > 0
+	ctx.Data["NewIssueChooseTemplate"] = ctx.HasIssueTemplatesOrContactLinks()
 	ctx.Data["RequireTribute"] = true
 	ctx.Data["PullRequestWorkInProgressPrefixes"] = setting.Repository.PullRequest.WorkInProgressPrefixes
 	title := ctx.FormString("title")
@@ -946,12 +946,16 @@ func NewIssueChooseTemplate(ctx *context.Context) {
 		ctx.Flash.Warning(renderErrorOfTemplates(ctx, errs), true)
 	}
 
-	if len(issueTemplates) == 0 {
+	if !ctx.HasIssueTemplatesOrContactLinks() {
 		// The "issues/new" and "issues/new/choose" share the same query parameters "project" and "milestone", if no template here, just redirect to the "issues/new" page with these parameters.
 		ctx.Redirect(fmt.Sprintf("%s/issues/new?%s", ctx.Repo.Repository.Link(), ctx.Req.URL.RawQuery), http.StatusSeeOther)
 		return
 	}
 
+	issueConfig, err := ctx.IssueConfigFromDefaultBranch()
+	ctx.Data["IssueConfig"] = issueConfig
+	ctx.Data["IssueConfigError"] = err // ctx.Flash.Err makes problems here
+
 	ctx.Data["milestone"] = ctx.FormInt64("milestone")
 	ctx.Data["project"] = ctx.FormInt64("project")
 
@@ -1086,7 +1090,7 @@ func NewIssuePost(ctx *context.Context) {
 	form := web.GetForm(ctx).(*forms.CreateIssueForm)
 	ctx.Data["Title"] = ctx.Tr("repo.issues.new")
 	ctx.Data["PageIsIssueList"] = true
-	ctx.Data["NewIssueChooseTemplate"] = len(ctx.IssueTemplatesFromDefaultBranch()) > 0
+	ctx.Data["NewIssueChooseTemplate"] = ctx.HasIssueTemplatesOrContactLinks()
 	ctx.Data["PullRequestWorkInProgressPrefixes"] = setting.Repository.PullRequest.WorkInProgressPrefixes
 	ctx.Data["IsAttachmentEnabled"] = setting.Attachment.Enabled
 	upload.AddUploadContext(ctx, "comment")
@@ -1280,7 +1284,7 @@ func ViewIssue(ctx *context.Context) {
 			return
 		}
 		ctx.Data["PageIsIssueList"] = true
-		ctx.Data["NewIssueChooseTemplate"] = len(ctx.IssueTemplatesFromDefaultBranch()) > 0
+		ctx.Data["NewIssueChooseTemplate"] = ctx.HasIssueTemplatesOrContactLinks()
 	}
 
 	if issue.IsPull && !ctx.Repo.CanRead(unit.TypeIssues) {

routers/web/repo/view.go

@@ -348,6 +348,9 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 	if ctx.Repo.TreePath == ".editorconfig" {
 		_, editorconfigErr := ctx.Repo.GetEditorconfig(ctx.Repo.Commit)
 		ctx.Data["FileError"] = editorconfigErr
+	} else if ctx.Repo.IsIssueConfig(ctx.Repo.TreePath) {
+		_, issueConfigErr := ctx.Repo.GetIssueConfig(ctx.Repo.TreePath, ctx.Repo.Commit)
+		ctx.Data["FileError"] = issueConfigErr
 	}
 
 	isDisplayingSource := ctx.FormString("display") == "source"