Only set head when it's empty

commands/pull_request.go

@@ -129,11 +129,13 @@ func pullRequest(cmd *Command, args *Args) {
 
 	}
 
+	if head == "" {
 		if trackedBranch == nil {
 			head = currentBranch.ShortName()
 		} else {
 			head = trackedBranch.ShortName()
 		}
+	}
 
 	title, body, err := getTitleAndBodyFromFlags(flagPullRequestMessage, flagPullRequestFile)
 	utils.Check(err)