list_metadata fail instead of returning nil or []

[RedaBenh]

Hi,

In my developper org i have 0 Apex Trigger.

2.1.0 :171 > client.list_metadata( "ApexTrigger")
D, [2016-04-15T18:27:44.615915 #14098] DEBUG -- : SOAP request: https://redabenh-dev-ed.my.salesforce.com/services/Soap/m/26.0/00Vd1000000cJSi
D, [2016-04-15T18:27:44.616004 #14098] DEBUG -- : Cookie: BrowserId=BNmDPaBlSGK_pcKFLoJTfg, SOAPAction: "listMetadata", Content-Type: text/xml;charset=UTF-8, Content-Length: 659
D, [2016-04-15T18:27:44.616034 #14098] DEBUG -- : <?xml version="1.0" encoding="UTF-8"?><env:Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tns="http://soap.sforce.com/2006/04/metadata" xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ins0="http://soap.sforce.com/2006/04/metadata"><env:Header><ins0:SessionHeader><ins0:sessionId>XXX</ins0:sessionId></ins0:SessionHeader></env:Header><env:Body><ins0:listMetadata><ins0:queries><ins0:type>ApexTrigger</ins0:type></ins0:queries></ins0:listMetadata></env:Body></env:Envelope>
W, [2016-04-15T18:27:44.616071 #14098]  WARN -- : HTTPI executes HTTP POST using the net_http adapter
D, [2016-04-15T18:27:45.720117 #14098] DEBUG -- : SOAP response (status 200):
D, [2016-04-15T18:27:45.720260 #14098] DEBUG -- : <?xml version="1.0" encoding="UTF-8"?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns="http://soap.sforce.com/2006/04/metadata"><soapenv:Body><listMetadataResponse/></soapenv:Body></soapenv:Envelope>
NoMethodError: undefined method `result' for nil:NilClass
    from /Users/redabenh/.rvm/gems/ruby-2.1.0/gems/metaforce-1.1.0/lib/metaforce/abstract_client.rb:55:in `perform_request'
    from /Users/redabenh/.rvm/gems/ruby-2.1.0/gems/metaforce-1.1.0/lib/metaforce/abstract_client.rb:42:in `request'
    from /Users/redabenh/.rvm/gems/ruby-2.1.0/gems/metaforce-1.1.0/lib/metaforce/metadata/client/file.rb:19:in `list_metadata'
    from (irb):171
    from /Users/redabenh/.rvm/rubies/ruby-2.1.0/bin/irb:11:in `<main>'

When i create a trigger and i run the same command the error disappear !

2.1.0 :172 > client.list_metadata( "ApexTrigger")
D, [2016-04-15T18:30:19.691714 #14098] DEBUG -- : SOAP request: https://redabenh-dev-ed.my.salesforce.com/services/Soap/m/26.0/00Vd1000000cJSi
D, [2016-04-15T18:30:19.691833 #14098] DEBUG -- : Cookie: BrowserId=BNmDPaBlSGK_pcKFLoJTfg, SOAPAction: "listMetadata", Content-Type: text/xml;charset=UTF-8, Content-Length: 659
D, [2016-04-15T18:30:19.691864 #14098] DEBUG -- : <?xml version="1.0" encoding="UTF-8"?><env:Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tns="http://soap.sforce.com/2006/04/metadata" xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ins0="http://soap.sforce.com/2006/04/metadata"><env:Header><ins0:SessionHeader><ins0:sessionId>XXX</ins0:sessionId></ins0:SessionHeader></env:Header><env:Body><ins0:listMetadata><ins0:queries><ins0:type>ApexTrigger</ins0:type></ins0:queries></ins0:listMetadata></env:Body></env:Envelope>
W, [2016-04-15T18:30:19.691904 #14098]  WARN -- : HTTPI executes HTTP POST using the net_http adapter
D, [2016-04-15T18:30:20.714124 #14098] DEBUG -- : SOAP response (status 200):
D, [2016-04-15T18:30:20.714264 #14098] DEBUG -- : <?xml version="1.0" encoding="UTF-8"?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns="http://soap.sforce.com/2006/04/metadata"><soapenv:Body><listMetadataResponse><result><createdById>005b0000000vWNJAA2</createdById><createdByName>Reda Benh</createdByName><createdDate>2016-04-15T16:30:01.000Z</createdDate><fileName>triggers/exampleTrigger.trigger</fileName><fullName>exampleTrigger</fullName><id>01qb0000000fzvyAAA</id><lastModifiedById>005b0000000vWNJAA2</lastModifiedById><lastModifiedByName>Reda Benh</lastModifiedByName><lastModifiedDate>2016-04-15T16:30:14.000Z</lastModifiedDate><manageableState>unmanaged</manageableState><type>ApexTrigger</type></result></listMetadataResponse></soapenv:Body></soapenv:Envelope>
 => #<Hashie::Mash created_by_id="005b0000000vWNJAA2" created_by_name="Reda Benh" created_date="2016-04-15T16:30:01.000Z" file_name="triggers/exampleTrigger.trigger" full_name="exampleTrigger" id="01qb0000000fzvyAAA" last_modified_by_id="005b0000000vWNJAA2" last_modified_by_name="Reda Benh" last_modified_date="2016-04-15T16:30:14.000Z" manageable_state="unmanaged" type="ApexTrigger"> 

i can reproduce this error with other empty Metadata Types.

Reda Benh