Change default SVN diffing tool

Question

Following a blog, I created a batch file, wm.bat:

\"d:\\svnroot\\external\\winmerge\\WinMerge.exe\" /B /WAIT \"d:\\svnroot\\external\\winmerge\\WinMergeU.exe         


        

Answer 1

I had 3 issues with the simple .bat file, especially when the revision didn't match the one in the working directory:

• svn may write the files to be compared to a temp directory - then delete them before WinMerge has a chance to look at them
• svn may pick up the file from an .svn\pristine subdirectory, where its filename is a long string of hex digits
• WinMerge bases its syntax highlighting on the file extensions and when svn uses a temp file, it has no extension

So I ended up wrapping a little PowerShell into the .bat file to work around these issues:

;@echo off
;set  leftdesc=%~3
;set rightdesc=%~5
;set  leftfile=%~6
;set rightfile=%~7
;Findstr -rbv ; %0 | powershell -c -
;goto:sCode

&{
  $leftExt, $rightExt = ($env:leftdesc, $env:rightdesc) -replace '.*([.]\w+).*','$1'
  if ($env:leftfile.EndsWith($leftExt)){
    $leftFile = $env:leftfile
  }else{
    $leftFile = Join-Path $env:temp ((Split-Path $env:leftfile -Leaf) + $leftExt)
    Copy-Item $env:leftfile $leftFile -Force
  }
  if ($env:rightfile.EndsWith($rightExt)){
    $rightFile = $env:rightfile
  }else{
    $rightFile = Join-Path $env:temp ((Split-Path $env:rightfile -Leaf) + $rightExt)
    Copy-Item $env:rightfile $rightFile -Force
  }
  $descriptions = '/dl "' + $env:leftdesc + '" /dr "' + $env:rightdesc + '"'
  $fileNames    = '"' + $leftFile + '" "' + $rightFile + '"'
  start 'C:\Program Files (x86)\WinMerge\WinMergeU.exe' ('/e /u ' +$descriptions + ' ' + $fileNames)
}

;:sCode
;goto :eof

Thanks to Walid Toumi for the wrapper.