Download .collabdiff file from Code Collaborator - powershell

Question

I want to be able to download patches associated with change lists in Code Collaborator using the Windows command line. These are the files you get in the web GUI if you click on External Diff. They have an extension ".collabdiff", and are in fact zipped archives containing folders for "before" and "after" of each file. I intend to use these to do a three-way merge using Subversion Merge.
My first approach was to use the Code Collaborator command line utility, e.g.
ccollab admin wget externaldiff?reviewid=%2^&changelistid=%3 > %OutputFile%
Unfortunately, it seems that this expects ASCII data only, because a lot of text appears on the screen, and there is a lot of beeping.
My next approach was to use the external link directly. To do this, I have reused a snippet of PowerShell script I found on the web:
::
:: GetCodeCollaboratorChangeList.cmd
::
:: Downloads a review change list from Code Collaborator.
::
:: %1 Code Collaborator Server
:: %2 Review Id
:: %3 Change List Id
::
#ECHO ON
SETLOCAL
SET OutputFile=%~dp0ChangeList_%2_%3.collabdiff
ECHO Creating %OutputFile%.
:: Sadly, the following line expects that ASCII text should be returned, but the URL returns binary text.
:: It beeps a little, and not much text gets redirected.
::ccollab admin wget externaldiff?reviewid=%2^&changelistid=%3 > %OutputFile%
:: So instead, we have to use our own download code.
SET URL="%1/externaldiff?reviewid=%2&changelistid=%3"
SET S=""
SET S="%S:~1,-1% $webclient = New-Object System.Net.WebClient;"
SET S="%S:~1,-1% $webclient.DownloadFile('%URL:~1,-1%','%OutputFile%');"
PowerShell.exe -ExecutionPolicy unrestricted -noprofile -command "& {%S:~1,-1%}"
EXIT /B
Sadly, I get the following error:
Exception calling "DownloadFile" with "2" argument(s): "The remote server returned an error: (500) Internal Server Error."
At line:1 char:74
+ & { $webclient = New-Object System.Net.WebClient; $webclient.DownloadFile <<<< ('http://server1/externaldiff?reviewid=8077&changelistid=52915','C:\Documents and Settings\Administrator\Desktop\ChangeList_8077_52915.collabdiff');}
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
When taking the URL and pasting it in the browser (rather than clicking on the link), you get the following page:
HTTP Status 500 -
--------------------------------------------------------------------------------
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
java.lang.NullPointerException
com.smartbear.ccollab.datamodel.DataModelUtils.getDefaultPrevVersionToDiff(DataModelUtils.java:379)
com.smartbear.ccollab.datamodel.DataModelUtils.getDefaultPrevVersionToDiff(DataModelUtils.java:351)
com.smartbear.ccollab.rpc.ExternalDiffConfigServlet.getVersionsToDiff(ExternalDiffConfigServlet.java:373)
com.smartbear.ccollab.rpc.ExternalDiffConfigServlet.service(ExternalDiffConfigServlet.java:140)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
com.smartbear.ccollab.AuthTicketFilter.doFilter(AuthTicketFilter.java:74)
com.smartbear.ccollab.CollabCleanupFilter.doFilter(CollabCleanupFilter.java:30)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.20-patched logs.
--------------------------------------------------------------------------------
Apache Tomcat/6.0.20-patched
I have tried modifying the code to modify QueryString and BaseAddress properties separately, and called .DownloadFile('/externaldiff, ...) but there was no change in the error.
Are there any suggestions as to how I can download these files?

Answer 1

Try:
ccollab admin wget 'diff?context=10&reviewid=REVIEWID'
Eg:
ccollab admin wget 'diff?context=10&reviewid=12345'