Add option to prohibit fork if user reached maximum limit of repositories (#21848)

If user has reached the maximum limit of repositories:

- Before
  - disallow create
  - allow fork without limit
- This patch:
  - disallow create
  - disallow fork
- Add option `ALLOW_FORK_WITHOUT_MAXIMUM_LIMIT` (Default **true**) :
enable this allow user fork repositories without maximum number limit

fixed https://github.com/go-gitea/gitea/issues/21847

Signed-off-by: Xinyu Zhou <i@sourcehut.net>

services/repository/fork_test.go

@@ -10,6 +10,7 @@ import (
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -29,4 +30,19 @@ func TestForkRepository(t *testing.T) {
 	assert.Nil(t, fork)
 	assert.Error(t, err)
 	assert.True(t, IsErrForkAlreadyExist(err))
+
+	// user not reached maximum limit of repositories
+	assert.False(t, repo_model.IsErrReachLimitOfRepo(err))
+
+	// change AllowForkWithoutMaximumLimit to false for the test
+	setting.Repository.AllowForkWithoutMaximumLimit = false
+	// user has reached maximum limit of repositories
+	user.MaxRepoCreation = 0
+	fork2, err := ForkRepository(git.DefaultContext, user, user, ForkRepoOptions{
+		BaseRepo:    repo,
+		Name:        "test",
+		Description: "test",
+	})
+	assert.Nil(t, fork2)
+	assert.True(t, repo_model.IsErrReachLimitOfRepo(err))
 }