On Thu, 19 Oct 2017 00:22:51 +0200
Jeremie Courreges-Anglas <[email protected]> wrote:

> Those variables are static so that error messages are only printed once
> in the shell lifetime.  history reload happens each time the shell
> detects that the histfile has been modified, which can happen often if
> like me you have multiple interactives shells running at the same time.
 
Makes sense, although I had been thinking that it could lead to lost
warnings when changing histfile; I'd hope that a corrupt histfile isn't
a persistent condition.

In any case, this looks pretty good to me.

> > Maybe hoist this outside of the loop.
> 
> I don't see a reason for this.
> 
> >> +                  /* no trailing newline? */
> >> +                  if (strlen(p) != sizeof(encoded) - 1) {
> >> +                          if (!corrupt) {
> >> +                                  corrupt = 1;
> >> +                                  bi_errorf("history file is corrupt");
> >> +                          }
> >> +                          return;
> >
> > Why does `corrupt` need to be recorded at all? There's a
> > return right after it.
> 
> Also to limit the amount of crap printed on screen, though maybe we
> should warn every time in this case.  Here's an updated diff that does
> so and hopefully makes the intents clearer.  It also adds a comment
> suggested by anton@
> 
> If your histfile ends with an overlong line which is also not terminated
> by a newline, the do...while loop would silently ignore this last line.
> I think that's acceptable, but YMMV.
> 
> 
> Index: history.c
> ===================================================================
> RCS file: /d/cvs/src/bin/ksh/history.c,v
> retrieving revision 1.72
> diff -u -p -p -u -r1.72 history.c
> --- history.c 18 Oct 2017 15:41:25 -0000      1.72
> +++ history.c 18 Oct 2017 22:16:43 -0000
> @@ -739,24 +739,42 @@ history_close(void)
>  static void
>  history_load(Source *s)
>  {
> -     char            *p, encoded[LINE + 1], line[LINE + 1];
> +     char            *nl, *p, encoded[LINE + 1], line[LINE + 1];
>  
>       rewind(histfh);
> +     line_co = 1;
>  
>       /* just read it all; will auto resize history upon next command */
> -     for (line_co = 1; ; line_co++) {
> -             p = fgets(encoded, sizeof(encoded), histfh);
> -             if (p == NULL || feof(histfh) || ferror(histfh))
> -                     break;
> -             if ((p = strchr(encoded, '\n')) == NULL) {
> -                     bi_errorf("history file is corrupt");
> -                     return;
> +     while ((p = fgets(encoded, sizeof(encoded), histfh)) != NULL) {
> +             if ((nl = strchr(encoded, '\n')) == NULL) {
> +                     static int warned;
> +
> +                     /* no trailing newline? */
> +                     if (strlen(p) != sizeof(encoded) - 1) {
> +                             bi_errorf("history file is corrupt");
> +                             return;
> +                     }
> +
> +                     if (!warned) {
> +                             warned = 1;
> +                             bi_errorf(
> +                                 "ignoring history line(s) longer than %d"
> +                                 " bytes", LINE);
> +                     }
> +
> +                     /* discard overlong line */
> +                     do {
> +                             p = fgets(encoded, sizeof(encoded), histfh);
> +                     } while (p != NULL && strchr(p, '\n') == NULL);
> +
> +                     continue;
>               }
> -             *p = '\0';
> +             *nl = '\0';
>               s->line = line_co;
>               s->cmd_offset = line_co;
>               strunvis(line, encoded);
>               histsave(line_co, line, 0);
> +             line_co++;
>       }
>  
>       history_write();
> 
> -- 
> jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF  DDCC 0DFA 74AE 1524 E7EE
> 


-- 
Ori Bernstein <[email protected]>

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