Problem Description

If You have Your Jenkinsfile in subdirectory, the result for searching is "Skipped"

Checking branch feature/JIR-123 from OWNER_1/repo_1
      ‘jenkins/build/my.Jenkinsfile’ not found
    Skipped

Multibranch Pipeline, mode: Jenkinsfile, Script path: jenkins/build/my.Jenkinsfile

Probably: BitbucketServerAPIClient.checkPathExists(..)

String url = UriTemplate
        .fromTemplate(API_BROWSE_PATH)
        .set("owner", "OWNER_1")
        .set("repo", "repo_1")
        .set("path", "jenkins/build/my.Jenkinsfile")
        .set("at", "feature/JIR-123")
        .expand();

url should contains "/rest/api/1.0/projects/OWNER_1/repos/repo_1/browse/jenkins/build/my.Jenkinsfile?at=feature%2FJIR-123"

not /rest/api/1.0/projects/OWNER_1/repos/repo_1/browse/jenkins%2Fbuild%2Fmy.Jenkinsfile?at=feature%2FJIR-123

Proposal for change (but I'm not sure about rules for UriTemplate):

120: private static final String API_BROWSE_PATH = API_REPOSITORY_PATH + "/browse/{+path}{?at}";

Or maybe it's a bug in UriTemplate as {/path} is recognized as PATH type.