repo: update repository description field to contain more than 256 symbols (#5219)

* Update repository description field to contain more than 256 symbols

- update repository model - description field now is `TEXT` and limited by 4000 symbols
- new migration
- add description to html forms - repo creation and repo settings
- add translation for description

* Update for description field, new features

- add autosize (height) for description textarea, new plugin
- set max description length to 512 symbols
- update locales

* Fix migration - typo in var

* Update repo description behaviour

- add textarea autosize for /repo/create
- add symbols counter under description testarea (create/edit)

* Fix function definition - it a var

* Revert ru-RU locale

* Update by review

- Use type `varchar(512)` in migration
- Remove unused files from autosize plugin

* Fix migration - new project paths

* Fixes after review 2

- copyright year
- format includes
- use switch instead of multi-if

* Remove unused `default:` option.

3 files changed, 39 insertions, 3 deletions

diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 432717c7..7e700f49 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -64,6 +64,8 @@ var migrations = []Migration{
 	NewMigration("update repository sizes", updateRepositorySizes),
 	// v16 -> v17:v0.10.31
 	NewMigration("remove invalid protect branch whitelist", removeInvalidProtectBranchWhitelist),
+	// v17 -> v18:v0.11.48
+	NewMigration("store long text in repository description field", updateRepositoryDescriptionField),
 }
 
 // Migrate database to current version
diff --git a/models/migrations/v18.go b/models/migrations/v18.go
new file mode 100644
index 00000000..086cd27a
--- /dev/null
+++ b/models/migrations/v18.go
@@ -0,0 +1,34 @@
+// Copyright 2018 The Gogs 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"
+
+	"github.com/gogs/gogs/pkg/setting"
+)
+
+func updateRepositoryDescriptionField(x *xorm.Engine) error {
+	exist, err := x.IsTableExist("repository")
+	if err != nil {
+		return fmt.Errorf("IsTableExist: %v", err)
+	} else if !exist {
+		return nil
+	}
+	switch {
+		case setting.UseMySQL:
+			_, err = x.Exec("ALTER TABLE `repository` MODIFY `description` VARCHAR(512);")
+		case setting.UseMSSQL:
+			_, err = x.Exec("ALTER TABLE `repository` ALTER COLUMN `description` VARCHAR(512);")
+		case setting.UsePostgreSQL:
+			_, err = x.Exec("ALTER TABLE `repository` ALTER COLUMN `description` TYPE VARCHAR(512);")
+		case setting.UseSQLite3:
+			// Sqlite3 uses TEXT type by default for any string type field.
+			// Keep this comment to mention that we don't missed any option.
+	}
+	return err
+}
diff --git a/models/repo.go b/models/repo.go
index 7a873afc..909af1d8 100644
--- a/models/repo.go
+++ b/models/repo.go
@@ -146,7 +146,7 @@ type Repository struct {
 	Owner         *User  `xorm:"-" json:"-"`
 	LowerName     string `xorm:"UNIQUE(s) INDEX NOT NULL"`
 	Name          string `xorm:"INDEX NOT NULL"`
-	Description   string
+	Description   string `xorm:"VARCHAR(512)"`
 	Website       string
 	DefaultBranch string
 	Size          int64 `xorm:"NOT NULL DEFAULT 0"`
@@ -1331,8 +1331,8 @@ func GetRepositoriesByForkID(forkID int64) ([]*Repository, error) {
 func updateRepository(e Engine, repo *Repository, visibilityChanged bool) (err error) {
 	repo.LowerName = strings.ToLower(repo.Name)
 
-	if len(repo.Description) > 255 {
-		repo.Description = repo.Description[:255]
+	if len(repo.Description) > 512 {
+		repo.Description = repo.Description[:512]
 	}
 	if len(repo.Website) > 255 {
 		repo.Website = repo.Website[:255]