Re: LYNX-DEV weird crashes

[Klaus Weide]

On Sat, 17 May 1997, Foteos Macrides wrote:

> >(dbx 1) where
> >  [1] pthread_mutexattr_setprotocol(0x27, 0x27, 0xb, 0x1b0a88, 0xefffcb7c,
> >     0x1), at 0xef634144
> >=>[2] FatalProblem(sig = 11), line 2239 in "LYMain.c"
> >  ---- called from signal handler with signal 11 (SIGSEGV) ------
> >  [3] LYno_attr_char_case_strstr(chptr = 0xa "",
>                                 ^^^^^^^^^^^^^^
> >     tarptr = 0xefffd9c4 "seven l"), line 762 in "LYStrings.c"
>       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
>       I took Klaus' word for it that there's no hidden problem to
> worry about with the native solaris compiler, but what does that
> [3] entry mean?  I had interpretted it to mean that you had an
> obsolete but still valid links[i].form structure for an INPUT
           ^^^^^^^^^^^^^^^
We don't know that.  *(links[i].form) may just be some place
in memory which was once used for a FormInfo structure, but now
is used for something else.  (I guess that can only happen if the
document which had that form isn't in the HText "cache" any more).

> that had no VALUE="foo" attribute, and thus had it set to a
> zero-length string, which was still valid, too, in the obsolete
> links[i].forms->value element of the obsolute links[i].forms
> structure.  So what's the right way to interpret those dbx
> outputs?

That 0xa is taken (by LYno_attr_char_case_strstr) to be a (char *),
i.e. a memory address.  It's an invalid one, because the space once
occupied by the FormInfo structure is now used for something else.
dbx appears to try to interpret it as a string, but that can only
give random garbage - for example "" if the byte stored at 0x0000000a
happens to be 0x00.

Well that's my explanation...

       Klaus
   

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