Add Pull Request merge options - Ignore white-space for conflict checking, Rebase, Squash merge (#3188)

* Pull request options migration and UI in settings

* Add ignore whitespace functionality

* Fix settings if pull requests are disabled

* Fix migration transaction

* Merge with Rebase functionality

* UI changes and related functionality for pull request merging button

* Implement squash functionality

* Fix rebase merging

* Fix pull request merge tests

* Add squash and rebase tests

* Fix API method to reuse default message functions

* Some refactoring and small fixes

* Remove more hardcoded values from tests

* Remove unneeded check from API method

* Fix variable name and comment typo

* Fix reset commit count after PR merge

1 files changed, 30 insertions, 4 deletions

diff --git a/models/repo_unit.go b/models/repo_unit.go
index 5100ca1ce2..49b62ec9cd 100644
--- a/models/repo_unit.go
+++ b/models/repo_unit.go
@@ -85,18 +85,44 @@ func (cfg *IssuesConfig) ToDB() ([]byte, error) {
 	return json.Marshal(cfg)
 }
 
+// PullRequestsConfig describes pull requests config
+type PullRequestsConfig struct {
+	IgnoreWhitespaceConflicts bool
+	AllowMerge                bool
+	AllowRebase               bool
+	AllowSquash               bool
+}
+
+// FromDB fills up a PullRequestsConfig from serialized format.
+func (cfg *PullRequestsConfig) FromDB(bs []byte) error {
+	return json.Unmarshal(bs, &cfg)
+}
+
+// ToDB exports a PullRequestsConfig to a serialized format.
+func (cfg *PullRequestsConfig) ToDB() ([]byte, error) {
+	return json.Marshal(cfg)
+}
+
+// IsMergeStyleAllowed returns if merge style is allowed
+func (cfg *PullRequestsConfig) IsMergeStyleAllowed(mergeStyle MergeStyle) bool {
+	return mergeStyle == MergeStyleMerge && cfg.AllowMerge ||
+		mergeStyle == MergeStyleRebase && cfg.AllowRebase ||
+		mergeStyle == MergeStyleSquash && cfg.AllowSquash
+}
+
 // BeforeSet is invoked from XORM before setting the value of a field of this object.
 func (r *RepoUnit) BeforeSet(colName string, val xorm.Cell) {
 	switch colName {
 	case "type":
 		switch UnitType(Cell2Int64(val)) {
-		case UnitTypeCode, UnitTypePullRequests, UnitTypeReleases,
-			UnitTypeWiki:
+		case UnitTypeCode, UnitTypeReleases, UnitTypeWiki:
 			r.Config = new(UnitConfig)
 		case UnitTypeExternalWiki:
 			r.Config = new(ExternalWikiConfig)
 		case UnitTypeExternalTracker:
 			r.Config = new(ExternalTrackerConfig)
+		case UnitTypePullRequests:
+			r.Config = new(PullRequestsConfig)
 		case UnitTypeIssues:
 			r.Config = new(IssuesConfig)
 		default:
@@ -116,8 +142,8 @@ func (r *RepoUnit) CodeConfig() *UnitConfig {
 }
 
 // PullRequestsConfig returns config for UnitTypePullRequests
-func (r *RepoUnit) PullRequestsConfig() *UnitConfig {
-	return r.Config.(*UnitConfig)
+func (r *RepoUnit) PullRequestsConfig() *PullRequestsConfig {
+	return r.Config.(*PullRequestsConfig)
 }
 
 // ReleasesConfig returns config for UnitTypeReleases