Re: [Bug-readline] readline 8.0 in windows

[JohnD]

> -----Original Message-----
> From: Chet Ramey [mailto:address@hidden
> Sent: Wednesday, April 03, 2019 4:29 PM
> To: JohnD; address@hidden
> Cc: address@hidden
> Subject: Re: [Bug-readline] readline 8.0 in windows
> 
> On 4/3/19 4:03 PM, JohnD wrote:
> >
> > Version: 8.0-release
> > Windows 10, mingw64-w64.
> >
> > I'm attempting to use readline in a mingw compiled project and am seeing
> > that the history save is failing. If the history file doesn't exist it is
> > working, on having a history file, it fails.
> >
> > Previously I was using v6.2 without any issues
> >
> > Printing the status out in the sources to find out where it fails, it is
> > failing in histfile_restore when calling the rename function, which looks to
> > have been added for version 7.0
> >
> >
> > According to http://www.cplusplus.com/reference/cstdio/rename/ if the dest
> > file already exists, the function may either fail or override the existing
> > file, depending on the specific system and library implementation.
> 
> Well, those are terrible semantics. So much for atomic rename and leaving
> newpath in place on a file system error.
> 
> I don't use Windows, but you could try adding
> 
> unlink(linkbuf);
> or
> unlink(orig);
> 
> before the calls to rename() (or, if you're using a version of readline
> distributed by MinGW, file a bug report with them). Let me know if it
> works.
> 
> Chet
> 
> --
> ``The lyf so short, the craft so long to lerne.'' - Chaucer
>                ``Ars longa, vita brevis'' - Hippocrates
> Chet Ramey, UTech, CWRU    address@hidden    http://tiswww.cwru.edu/~chet/


Msys2 recently went to 8.0
https://github.com/msys2/MINGW-packages/pull/5011

I'll verify it doesn’t work there and let them know


For reference, Windoze does have its own 'rename' like function
https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-movefileexa

So I was going to try adding something like:
static int
history_rename(const char *from, const char *to)
{
#if defined(_WIN32)
  if (!MoveFileEx(from, to, MOVEFILE_REPLACE_EXISTING)) {
    return -1;
  }
  return 0;
#else
  return rename(from, to);
#endif
}

And change the rename calls to history_rename