Improve valid user name check

models/db/name.go

@@ -7,18 +7,12 @@ package db
 import (
 	"errors"
 	"fmt"
-	"regexp"
 	"strings"
 	"unicode/utf8"
 )
 
-var (
-	// ErrNameEmpty name is empty error
-	ErrNameEmpty = errors.New("Name is empty")
-
-	// AlphaDashDotPattern characters prohibited in a user name (anything except A-Za-z0-9_.-)
-	AlphaDashDotPattern = regexp.MustCompile(`[^\w-\.]`)
-)
+// ErrNameEmpty name is empty error
+var ErrNameEmpty = errors.New("name is empty")
 
 // ErrNameReserved represents a "reserved name" error.
 type ErrNameReserved struct {

models/repo/repo.go

@@ -48,7 +48,7 @@ var (
 
 // IsUsableRepoName returns true when repository is usable
 func IsUsableRepoName(name string) error {
-	if db.AlphaDashDotPattern.MatchString(name) {
+	if user_model.IsValidUsername(name) {
 		// Note: usually this error is normally caught up earlier in the UI
 		return db.ErrNameCharsNotAllowed{Name: name}
 	}

models/user/name.go

@@ -0,0 +1,14 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.package db
+
+package user
+
+import "regexp"
+
+var validUsernamePattern = regexp.MustCompile(`^[\da-zA-Z][-.\w]*$`)
+
+// IsValidUsername checks if name is valid
+func IsValidUsername(name string) bool {
+	return validUsernamePattern.MatchString(name)
+}

models/user/name_test.go

@@ -0,0 +1,22 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.package db
+
+package user
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsValidUsername(t *testing.T) {
+	assert.True(t, IsValidUsername("a"))
+	assert.True(t, IsValidUsername("abc"))
+	assert.True(t, IsValidUsername("0.b-c"))
+
+	assert.False(t, IsValidUsername(""))
+	assert.False(t, IsValidUsername(".abc"))
+	assert.False(t, IsValidUsername("a/bc"))
+	assert.False(t, IsValidUsername("☁️"))
+}

models/user/user.go

@@ -608,7 +608,7 @@ var (
 // IsUsableUsername returns an error when a username is reserved
 func IsUsableUsername(name string) error {
 	// Validate username make sure it satisfies requirement.
-	if db.AlphaDashDotPattern.MatchString(name) {
+	if IsValidUsername(name) {
 		// Note: usually this error is normally caught up earlier in the UI
 		return db.ErrNameCharsNotAllowed{Name: name}
 	}