Fix 500 when deleting account with incorrect password or unsupported login type (#29579)

Fix #26210

---------

Co-authored-by: Jason Song <i@wolfogre.com>

options/locale/locale_en-US.ini

@@ -584,6 +584,8 @@ enterred_invalid_repo_name = The repository name you entered is incorrect.
 enterred_invalid_org_name = The organization name you entered is incorrect.
 enterred_invalid_owner_name = The new owner name is not valid.
 enterred_invalid_password = The password you entered is incorrect.
+unset_password = The login user has not set the password.
+unsupported_login_type = The login type is not supported to delete account.
 user_not_exist = The user does not exist.
 team_not_exist = The team does not exist.
 last_org_owner = You cannot remove the last user from the 'owners' team. There must be at least one owner for an organization.

routers/web/user/setting/account.go

@@ -19,6 +19,8 @@ import (
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/services/auth"
+	"code.gitea.io/gitea/services/auth/source/db"
+	"code.gitea.io/gitea/services/auth/source/smtp"
 	"code.gitea.io/gitea/services/context"
 	"code.gitea.io/gitea/services/forms"
 	"code.gitea.io/gitea/services/mailer"
@@ -242,11 +244,24 @@ func DeleteAccount(ctx *context.Context) {
 	ctx.Data["PageIsSettingsAccount"] = true
 
 	if _, _, err := auth.UserSignIn(ctx, ctx.Doer.Name, ctx.FormString("password")); err != nil {
-		if user_model.IsErrUserNotExist(err) {
+		switch {
+		case user_model.IsErrUserNotExist(err):
+			loadAccountData(ctx)
+
+			ctx.RenderWithErr(ctx.Tr("form.user_not_exist"), tplSettingsAccount, nil)
+		case errors.Is(err, smtp.ErrUnsupportedLoginType):
+			loadAccountData(ctx)
+
+			ctx.RenderWithErr(ctx.Tr("form.unsupported_login_type"), tplSettingsAccount, nil)
+		case errors.As(err, &db.ErrUserPasswordNotSet{}):
+			loadAccountData(ctx)
+
+			ctx.RenderWithErr(ctx.Tr("form.unset_password"), tplSettingsAccount, nil)
+		case errors.As(err, &db.ErrUserPasswordInvalid{}):
 			loadAccountData(ctx)
 
 			ctx.RenderWithErr(ctx.Tr("form.enterred_invalid_password"), tplSettingsAccount, nil)
-		} else {
+		default:
 			ctx.ServerError("UserSignIn", err)
 		}
 		return