Allow detect whether it's in a database transaction for a context.Context (#21756)

Fix #19513

This PR introduce a new db method `InTransaction(context.Context)`,
and also builtin check on `db.TxContext` and `db.WithTx`.
There is also a new method `db.AutoTx` has been introduced but could be used by other PRs.

`WithTx` will always open a new transaction, if a transaction exist in context, return an error.
`AutoTx` will try to open a new transaction if no transaction exist in context.
That means it will always enter a transaction if there is no error.

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: 6543 <6543@obermui.de>

models/asymkey/gpg_key.go

@@ -234,7 +234,7 @@ func DeleteGPGKey(doer *user_model.User, id int64) (err error) {
 		return ErrGPGKeyAccessDenied{doer.ID, key.ID}
 	}
 
-	ctx, committer, err := db.TxContext()
+	ctx, committer, err := db.TxContext(db.DefaultContext)
 	if err != nil {
 		return err
 	}

models/asymkey/gpg_key_add.go

@@ -73,7 +73,7 @@ func AddGPGKey(ownerID int64, content, token, signature string) ([]*GPGKey, erro
 		return nil, err
 	}
 
-	ctx, committer, err := db.TxContext()
+	ctx, committer, err := db.TxContext(db.DefaultContext)
 	if err != nil {
 		return nil, err
 	}

models/asymkey/gpg_key_verify.go

@@ -31,7 +31,7 @@ import (
 
 // VerifyGPGKey marks a GPG key as verified
 func VerifyGPGKey(ownerID int64, keyID, token, signature string) (string, error) {
-	ctx, committer, err := db.TxContext()
+	ctx, committer, err := db.TxContext(db.DefaultContext)
 	if err != nil {
 		return "", err
 	}

models/asymkey/ssh_key.go

@@ -100,7 +100,7 @@ func AddPublicKey(ownerID int64, name, content string, authSourceID int64) (*Pub
 		return nil, err
 	}
 
-	ctx, committer, err := db.TxContext()
+	ctx, committer, err := db.TxContext(db.DefaultContext)
 	if err != nil {
 		return nil, err
 	}
@@ -321,7 +321,7 @@ func PublicKeyIsExternallyManaged(id int64) (bool, error) {
 // deleteKeysMarkedForDeletion returns true if ssh keys needs update
 func deleteKeysMarkedForDeletion(keys []string) (bool, error) {
 	// Start session
-	ctx, committer, err := db.TxContext()
+	ctx, committer, err := db.TxContext(db.DefaultContext)
 	if err != nil {
 		return false, err
 	}

models/asymkey/ssh_key_deploy.go

@@ -126,7 +126,7 @@ func AddDeployKey(repoID int64, name, content string, readOnly bool) (*DeployKey
 		accessMode = perm.AccessModeWrite
 	}
 
-	ctx, committer, err := db.TxContext()
+	ctx, committer, err := db.TxContext(db.DefaultContext)
 	if err != nil {
 		return nil, err
 	}

models/asymkey/ssh_key_principals.go

@@ -26,7 +26,7 @@ import (
 
 // AddPrincipalKey adds new principal to database and authorized_principals file.
 func AddPrincipalKey(ownerID int64, content string, authSourceID int64) (*PublicKey, error) {
-	ctx, committer, err := db.TxContext()
+	ctx, committer, err := db.TxContext(db.DefaultContext)
 	if err != nil {
 		return nil, err
 	}

models/asymkey/ssh_key_verify.go

@@ -15,7 +15,7 @@ import (
 
 // VerifySSHKey marks a SSH key as verified
 func VerifySSHKey(ownerID int64, fingerprint, token, signature string) (string, error) {
-	ctx, committer, err := db.TxContext()
+	ctx, committer, err := db.TxContext(db.DefaultContext)
 	if err != nil {
 		return "", err
 	}