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https://issues.apache.org/jira/browse/CLI-284?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16507368#comment-16507368
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ASF GitHub Bot commented on CLI-284:
------------------------------------

Github user sfuhrm commented on the issue:

    https://github.com/apache/commons-cli/pull/25
  
    Hi @kinow 
    
    thanks for your review! Oops, my maven build had a hickup and all tests 
were green.
    
    There's a design problem in the code you pointed me to. Every Option 
instance may be illegal (short and long == null) until first use. OptionBuilder 
(line 356) insists on creating an Option instance even if he long parameter is 
missing. Option.Builder does something similar.
    The setting happens after Option instance construction.



> Inconsistency in constraints for creating an instance of class Option using 
> builder pattern or constructor
> ----------------------------------------------------------------------------------------------------------
>
>                 Key: CLI-284
>                 URL: https://issues.apache.org/jira/browse/CLI-284
>             Project: Commons CLI
>          Issue Type: Bug
>            Reporter: Dilraj Singh
>            Assignee: Bruno P. Kinoshita
>            Priority: Major
>         Attachments: CLI284.patch
>
>
> Builder pattern for creating an instance of class *Option* ensures that at 
> least one of the representation (short and long representation) for the 
> option is not null. It throws an *IllegalArgumentException* in-case program 
> tries to build an instance with both the representations as null. Consider 
> the following code snippet for reference.
> {code:java}
> public static void main(String[] args) {
>   Option.Builder builder = Option.builder();
>   Option op = builder.build();
> } 
> {code}
> This piece of code fails with the following exception
> {noformat}
> Exception in thread "main" java.lang.IllegalArgumentException: Either opt or 
> longOpt must be specified
> {noformat}
> But if we try to create an instance of Option by calling its constructor, It 
> allows the creation with both opt and longOpt for Option as null. Consider 
> the following code snippet for reference
> {code:java}
> public static void main(String[] args) {
>   Option op = new Option(null, null);
>   System.out.format("Short Representation: %s\n" +
>   "Long Representation: %s", op.getOpt(), 
>   op.getLongOpt());
> }
> {code}
> Output:
> {noformat}
> Short Representation: null
> Long Representation: null
> {noformat}
> Calling a method on an instance with both opt and longOpt as null will lead 
> to undesired null pointer exception. For example, calling
> {code:java}
>  op.getId() {code}
> will throw a null pointer exception, thus violating the method contract.
> So as to fix this we need to make sure that whenever a constructor is invoked 
> it has a non-null argument value for at least one of the Option 
> representation. 



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