Enable partial clone by default (#18195)

- Enable partial clones(which are by default disabled from git) by
default, unless configured otherwise.
- Resolves #18190

modules/git/git.go

@@ -146,6 +146,11 @@ func Init(ctx context.Context) error {
 		GlobalCommandArgs = append(GlobalCommandArgs, "-c", "protocol.version=2")
 	}
 
+	// By default partial clones are disabled, enable them from git v2.22
+	if !setting.Git.DisablePartialClone && CheckGitVersionAtLeast("2.22") == nil {
+		GlobalCommandArgs = append(GlobalCommandArgs, "-c", "uploadpack.allowfilter=true")
+	}
+
 	// Save current git version on init to gitVersion otherwise it would require an RWMutex
 	if err := LoadGitVersion(); err != nil {
 		return err

modules/setting/git.go

@@ -27,6 +27,7 @@ var (
 		PullRequestPushMessage    bool
 		LargeObjectThreshold      int64
 		DisableCoreProtectNTFS    bool
+		DisablePartialClone       bool
 		Timeout                   struct {
 			Default int
 			Migrate int
@@ -48,6 +49,7 @@ var (
 		EnableAutoGitWireProtocol: true,
 		PullRequestPushMessage:    true,
 		LargeObjectThreshold:      1024 * 1024,
+		DisablePartialClone:       false,
 		Timeout: struct {
 			Default int
 			Migrate int