Re: bug in readline.c

[Thomas Klausner <tk%giga.or.at@localhost>]

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Thanks,
 Thomas

On Tue, Aug 20, 2019 at 05:27:04PM +0800, Changqing Li wrote:
> Hi,
> 
> First,  if this is not the right place to send the patch, please let me
> know, thanks.
> 
> There is a bug in readline.c,  here is reproduce steps and patch to fix it, 
> @christos, please help to review it, thanks.
> 
> Reproduce steps:
> 
> 1. Download libedit from https://www.thrysoee.dk/editline/
> 
> 2. config and build libedit, and then run fileman under examples folder
> 
> 3.  history command  not work, no history is outputted.
> 
>     FileMan: help
> cd        Change to directory DIR.
> delete        Delete FILE.
> help        Display this text.
> ?        Synonym for `help'.
> list        List files in DIR.
> ls        Synonym for `list'.
> pwd        Print the current working directory.
> quit        Quit using Fileman.
> rename        Rename FILE to NEWNAME.
> stat        Print out statistics on FILE.
> view        View the contents of FILE.
> history        List editline history.
> FileMan: history
> FileMan:
> 
> Expect result:
> 
> FileMan: help
> cd        Change to directory DIR.
> delete        Delete FILE.
> help        Display this text.
> ?        Synonym for `help'.
> list        List files in DIR.
> ls        Synonym for `list'.
> pwd        Print the current working directory.
> quit        Quit using Fileman.
> rename        Rename FILE to NEWNAME.
> stat        Print out statistics on FILE.
> view        View the contents of FILE.
> history        List editline history.
> FileMan: history
> help
> history
> FileMan:
> 
> 4. libedit use readline.c v1.151
> 
> 
> Patch:
> 
> --- readline.c    2019-08-20 17:05:28.338507034 +0800
> +++ readline.c.orig    2019-08-20 17:04:19.724864404 +0800
> @@ -1476,11 +1476,7 @@
>      if (ev.num == history_length)
>          history_base++;
>      else
> -    {
> -            history_offset++;
> -             history_length = ev.num;
> -        }
> -
> +        history_length = ev.num;
>      return 0;
>  }
> 
> if history_offset not increate when add history, it will make current
> history event
> 
> not align with offset,  and cannot get history correctly. and problem caused
> by this
> 
> commit:
> 
> http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libedit/readline.c.diff?r1=1.136&r2=1.137&only_with_tag=MAIN&f=h
> 
> 
> -- 
> BRs
> 
> Sandy(Li Changqing)
>