contrib/editmergeps.ps1

dirstate-v2: Support appending to the same data file

For now we’re still writing the entire data every time, so appending is not
useful yet. Later we’ll have new nodes pointing to some existing data for
nodes and paths that haven’t changed.

The decision whether to append is pseudo-random in order to make tests exercise
both code paths. This will be replaced by a heuristic based on the amount
of unused existing data.

Differential Revision: https://phab.mercurial-scm.org/D11094

# A simple script for opening merge conflicts in editor
# A loose translation of contrib/editmerge to powershell
# Please make sure that both editmergeps.bat and editmerge.ps1 are available
# via %PATH% and use the following Mercurial settings to enable it
#
# [ui]
# editmergeps
# editmergeps.args=$output
# editmergeps.check=changed
# editmergeps.premerge=keep

$file=$args[0]

function Get-Lines
{
  Select-String "^<<<<<<" $file | % {"$($_.LineNumber)"}
}

$ed = $Env:HGEDITOR;
if ($ed -eq $nil)
{
  $ed = $Env:VISUAL;
}
if ($ed -eq $nil)
{
  $ed = $Env:EDITOR;
}
if ($ed -eq $nil)
{
  $ed = $(hg showconfig ui.editor);
}
if ($ed -eq $nil)
{
  Write-Error "merge failed - unable to find editor"
  exit 1
}

if (($ed -eq "vim") -or ($ed -eq "emacs") -or `
    ($ed -eq "nano") -or ($ed -eq "notepad++"))
{
  $lines = Get-Lines
  $firstline = if ($lines.Length -gt 0) { $lines[0] } else { $nil }
  $previousline = $nil;


  # open the editor to the first conflict until there are no more
  # or the user stops editing the file
  while (($firstline -ne $nil) -and ($firstline -ne $previousline))
  {
    if ($ed -eq "notepad++")
    {
        $linearg = "-n$firstline"
    }
    else
    {
        $linearg = "+$firstline"
    }

    Start-Process -Wait -NoNewWindow $ed $linearg,$file
    $previousline = $firstline
    $lines = Get-Lines
    $firstline = if ($lines.Length -gt 0) { $lines[0] } else { $nil }
  }
}
else
{
  & "$ed" $file
}

$conflicts=Get-Lines
if ($conflicts.Length -ne 0)
{
  Write-Output "merge failed - resolve the conflicts (line $conflicts) then use 'hg resolve --mark'"
  exit 1
}

exit 0