Backport of 2611 / Fix doubled issue tab introduced in migration v16 (#2622)

Signed-off-by: David Schneiderbauer <dschneiderbauer@gmail.com>

models/migrations/migrations.go

@@ -130,6 +130,8 @@ var migrations = []Migration{
 	NewMigration("fix protected branch can push value to false", fixProtectedBranchCanPushValue),
 	// v42 -> v43
 	NewMigration("add tags to releases and sync existing repositories", releaseAddColumnIsTagAndSyncTags),
+	// v44 -> v45
+	NewMigration("remove duplicate unit types", removeDuplicateUnitTypes),
 }
 
 // Migrate database to current version

models/migrations/v44.go

@@ -0,0 +1,69 @@
+// Copyright 2017 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 migrations
+
+import (
+	"fmt"
+
+	"github.com/go-xorm/xorm"
+)
+
+func removeDuplicateUnitTypes(x *xorm.Engine) error {
+	// RepoUnit describes all units of a repository
+	type RepoUnit struct {
+		RepoID int64
+		Type   int
+	}
+
+	// Enumerate all the unit types
+	const (
+		UnitTypeCode            = iota + 1 // 1 code
+		UnitTypeIssues                     // 2 issues
+		UnitTypePullRequests               // 3 PRs
+		UnitTypeReleases                   // 4 Releases
+		UnitTypeWiki                       // 5 Wiki
+		UnitTypeExternalWiki               // 6 ExternalWiki
+		UnitTypeExternalTracker            // 7 ExternalTracker
+	)
+
+	var externalIssueRepoUnits []RepoUnit
+	err := x.Where("type = ?", UnitTypeExternalTracker).Find(&externalIssueRepoUnits)
+	if err != nil {
+		return fmt.Errorf("Query repositories: %v", err)
+	}
+
+	var externalWikiRepoUnits []RepoUnit
+	err = x.Where("type = ?", UnitTypeExternalWiki).Find(&externalWikiRepoUnits)
+	if err != nil {
+		return fmt.Errorf("Query repositories: %v", err)
+	}
+
+	sess := x.NewSession()
+	defer sess.Close()
+
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+
+	for _, repoUnit := range externalIssueRepoUnits {
+		if _, err = sess.Delete(&RepoUnit{
+			RepoID: repoUnit.RepoID,
+			Type:   UnitTypeIssues,
+		}); err != nil {
+			return fmt.Errorf("Delete repo unit: %v", err)
+		}
+	}
+
+	for _, repoUnit := range externalWikiRepoUnits {
+		if _, err = sess.Delete(&RepoUnit{
+			RepoID: repoUnit.RepoID,
+			Type:   UnitTypeWiki,
+		}); err != nil {
+			return fmt.Errorf("Delete repo unit: %v", err)
+		}
+	}
+
+	return sess.Commit()
+}