On Sat 12 Feb 2022 at 23:25:55 -0800, David Chmelik wrote: > > When a segfault occurs, execute the command "backtrace". > This is some further information seen when running it and the > backtrace, The only thing different last few years is I've been trying to > read a few hundred newsgroups on Eternal-September (backup server AIOE) and > Gmane. > > IA__gtk_tree_view_column_set_fixed_width: assertion 'fixed_width > 0' failed > IA__gdk_window_get_state: assertion 'GDK_IS_WINDOW (window)' failed > > (gdb) backtrace > #0 0x00007ffff6acf4bc in ____strtoll_l_internal () at /lib64/libc.so.6 > #1 0x00007ffff6acb710 in atoi () at /lib64/libc.so.6 > #2 0x0000000000730692 in pan::DataImpl::load_headers(pan::DataIO const&, > pan::Quark const&) (this=0x7fffffffd340, data_io=..., group=...) > at headers.cc:573
Ok, I'm not familiar with this code and I also haven't tried it in a
debugger, but here is some analysis from just observing.
If in frame # atoi() crashes, it must have gotten a bad pointer (such as
NULL). It gets it from line 573 in headers.cc:
if (gotline && !expired)
{
StringView tok;
s.ltrim ();
s.pop_token (tok);
const int number (atoi (tok.str)); <<< here
s is also a StringView, and pop_token puts the next word from it in tok:
bool
StringView :: pop_token (StringView& token, char delimiter)
{
const bool got_token (len != 0);
const char * pch = strchr (delimiter);
if (pch) {
token.str = str;
token.len = pch - str;
len -= token.len+1;
str += token.len+1;
} else {
token.str = str;
token.len = len;
str = 0;
len = 0;
}
return got_token;
}
token.src can never be a NULL pointer unless (this.)str already is NULL.
It looks like s.ltrim() can leave the str pointer NULL, if the string is
empty after trimming whitespace:
void
StringView :: ltrim ()
{
// strip leading whitespace
if (!empty()) {
..blah..
eat_chars (p-str);
}
}
void
StringView :: eat_chars (size_t n)
{
n = std::min (n, len);
len -= n;
str = len ? str+n : 0; <<<< here: can set to NULL
}
For this case, it would probably to to check tok.empty() before doing
calling atoi (tok.str).
I'm not sure what input it's trying to parse there: input from an nntp
server, or data that Pan wrote to a file earlier. In any case, clearly
it needs more checks. There are several other cases a bit earlier in the
file where atoi(tok.str) is called without checking if the token is
valid or not...
-Olaf.
--
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\X/ have kids to make his activity cost neutral." -The BOFH falu.nl@rhialto
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