annotate contrib/editmergeps.ps1 @ 47941:5b9de38a0356 stable

narrow: fix commits of empty files

The problem is that when committing a new file with empty contents (or
in general empty file with filelog p1 = -1), hg commit with narrow
doesn't create a filelog revision at all, which causes failures in
further commands.

The problem seems to be that:
- hg thinks that instead of creating a new filelog revision, it can
  use the filelog's p1 (the nullrev)
- because it thinks the file contents is the same in that revision and
  in p1
- because `narrowfilelog.cmp(nullrev, b'')` is True (unlike with
  `filelog.cmp`)

It's not clear to me which `cmp` behaves better. But I think it makes
sense to change the commit code to not to "reuse" the null rev when
adding an empty file with filelog p1 == filelog p2 == -1. This is
consistent with never writing the null rev in the manifest, which `hg
verify` claims is an invariant:

```
inside/c@4: manifest refers to unknown revision 000000000000
```

Differential Revision: https://phab.mercurial-scm.org/D11400

# 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