Fix org contact email not clearable once set (#36975)

When the email field was submitted as empty in org settings (web and
API), the previous guard `if form.Email != ""` silently skipped the
update, making it impossible to remove a contact email after it was set.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

services/org/org.go

@@ -168,3 +168,20 @@ func ChangeOrganizationVisibility(ctx context.Context, org *org_model.Organizati
 		return nil
 	})
 }
+
+// UpdateOrgEmailAddress validates and updates the organization's contact email.
+// A nil email means no change.
+func UpdateOrgEmailAddress(ctx context.Context, org *org_model.Organization, email *string) error {
+	if email == nil {
+		return nil
+	}
+
+	if *email != "" {
+		if err := user_model.ValidateEmail(*email); err != nil {
+			return err
+		}
+	}
+
+	org.Email = *email
+	return user_model.UpdateUserCols(ctx, org.AsUser(), "email")
+}

services/org/org_test.go

@@ -10,28 +10,54 @@ import (
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/util"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestMain(m *testing.M) {
 	unittest.MainTest(m)
 }
 
-func TestDeleteOrganization(t *testing.T) {
-	assert.NoError(t, unittest.PrepareTestDatabase())
-	org := unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 6})
-	assert.NoError(t, DeleteOrganization(t.Context(), org, false))
-	unittest.AssertNotExistsBean(t, &organization.Organization{ID: 6})
-	unittest.AssertNotExistsBean(t, &organization.OrgUser{OrgID: 6})
-	unittest.AssertNotExistsBean(t, &organization.Team{OrgID: 6})
+func TestOrg(t *testing.T) {
+	require.NoError(t, unittest.PrepareTestDatabase())
 
-	org = unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 3})
-	err := DeleteOrganization(t.Context(), org, false)
-	assert.Error(t, err)
-	assert.True(t, repo_model.IsErrUserOwnRepos(err))
+	t.Run("UpdateOrgEmailAddress", func(t *testing.T) {
+		org := unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 3})
+		originalEmail := org.Email
 
-	user := unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 5})
-	assert.Error(t, DeleteOrganization(t.Context(), user, false))
-	unittest.CheckConsistencyFor(t, &user_model.User{}, &organization.Team{})
+		require.NoError(t, UpdateOrgEmailAddress(t.Context(), org, nil))
+		unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 3, Email: originalEmail})
+
+		newEmail := "contact@org3.example.com"
+		require.NoError(t, UpdateOrgEmailAddress(t.Context(), org, &newEmail))
+		unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 3, Email: newEmail})
+
+		invalidEmail := "invalid email"
+		err := UpdateOrgEmailAddress(t.Context(), org, &invalidEmail)
+		require.ErrorIs(t, err, util.ErrInvalidArgument)
+		unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 3, Email: newEmail})
+
+		require.NoError(t, UpdateOrgEmailAddress(t.Context(), org, new("")))
+		org = unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 3, Email: ""})
+		assert.Empty(t, org.Email)
+	})
+
+	t.Run("DeleteOrganization", func(t *testing.T) {
+		org := unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 6})
+		assert.NoError(t, DeleteOrganization(t.Context(), org, false))
+		unittest.AssertNotExistsBean(t, &organization.Organization{ID: 6})
+		unittest.AssertNotExistsBean(t, &organization.OrgUser{OrgID: 6})
+		unittest.AssertNotExistsBean(t, &organization.Team{OrgID: 6})
+
+		org = unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 3})
+		err := DeleteOrganization(t.Context(), org, false)
+		assert.Error(t, err)
+		assert.True(t, repo_model.IsErrUserOwnRepos(err))
+
+		user := unittest.AssertExistsAndLoadBean(t, &organization.Organization{ID: 5})
+		assert.Error(t, DeleteOrganization(t.Context(), user, false))
+		unittest.CheckConsistencyFor(t, &user_model.User{}, &organization.Team{})
+	})
 }