NPE in DuplicateKeyException constructor

[Marc O'Morain]

We've hit a NPE in when constructing a DuplicateKeyException

The call stack is:

File DuplicateKeyException.java line 24 in org.yaml.snakeyaml.constructor.DuplicateKeyException.<init>
File SafeConstructor.java line 100 in org.yaml.snakeyaml.constructor.SafeConstructor.processDuplicateKeys
File SafeConstructor.java line 70 in org.yaml.snakeyaml.constructor.SafeConstructor.flattenMapping
File SafeConstructor.java line 183 in org.yaml.snakeyaml.constructor.SafeConstructor.constructMapping2ndStep
File BaseConstructor.java line 434 in org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping
File SafeConstructor.java line 521 in org.yaml.snakeyaml.constructor.SafeConstructor$ConstructYamlMap.construct
File BaseConstructor.java line 204 in org.yaml.snakeyaml.constructor.BaseConstructor.constructObjectNoCheck
File BaseConstructor.java line 193 in org.yaml.snakeyaml.constructor.BaseConstructor.constructObject
File BaseConstructor.java line 159 in org.yaml.snakeyaml.constructor.BaseConstructor.constructDocument
File BaseConstructor.java line 146 in org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData
File Yaml.java line 524 in org.yaml.snakeyaml.Yaml.loadFromReader
File Yaml.java line 437 in org.yaml.snakeyaml.Yaml.load

Using org.yaml/snakeyaml 1.23.

I've not tried to debug the issue yet - step 1 I wanted to log the bug.

Our internal URL to track this at CircleCI is https://rollbar.com/circle/orb-service/items/116/ (logging this for our own reference).

I'll try to get the offending YAML document, I don't have it available at present.

[Marc O'Morain]

Here is an example that fails:

~: foo
~: bar

This throws:

Error: NullPointerException   org.yaml.snakeyaml.constructor.DuplicateKeyException.<init> (DuplicateKeyException.java:24)

[Andrey Somov]

I will have a look.

[Marc O'Morain]

Thanks Andrey.

This should fix it:

public class DuplicateKeyException extends ConstructorException {

    protected DuplicateKeyException(Mark contextMark, Object key,
                                    Mark problemMark) {
        super("while constructing a mapping", contextMark, "found duplicate key " + String.valueOf(key), problemMark);
    }
}

[Marc O'Morain]

My Yaml is being parsed using the following loader (from Clojure):

(defn strict-loader-options ^LoaderOptions []
  (doto (LoaderOptions.)
    (.setAllowDuplicateKeys false)))

(defn strict-loader ^Yaml []
  (Yaml. (SafeConstructor.)
         (Representer.)
         (DumperOptions.)
         (strict-loader-options)))

[Andrey Somov]

Thank you very much.

Your fix will be delivered in version 1.24 (https://bitbucket.org/asomov/snakeyaml/wiki/Changes)

[Marc O'Morain]

Thank you Andrey (and thank you for all the time that you spend on this library).

Will you be able to publish the new version soon? I see that you try to release twice a year – and the next release is due in February). Will you be able to publish a new jar before then?

Marc

[Andrey Somov]

Dear Marc, the code has production quality if the tests are green. You can build it with your own classifier and upload to a repository for internal usage.

You can also take the latest snapshot: https://bitbucket.org/asomov/snakeyaml/wiki/Installation