Simple but crucial bug fix to gdb

[Jim Blandy]

Fernando Nasser <fnasser@redhat.com> writes:
> Irrelevant to the fact that his compiler may not be doing the right
> thing, GDB should not be dumping core.

That's absolutely true.

> I sincerely expect that you provide us with the "more correct" fix asap.

Please, don't be upset.  I can't provide a more correct fix without
understanding the user's situation more.  I asked him a question in a
message before the one I sent you, and I'm waiting to see what he
says.

Each partial symbol table object has an address range, textlow and
texthigh, which is supposed to enclose all the functions it covers.
If that address range is not set correctly, then GDB may not be able
to find the full symbols for a given text address.

The user has a stabs file which manages to get textlow_not_set cleared
(indicating that pst->textlow has been set), while pst is zero.  This
is very curious --- if the pst is zero, which textlow was it that got
set?

There's something very odd (or, as Daniel would have me say, even
odder than usual) going on here.  Rather than slap a test for null
over the problem and have it disappear, I want to try to understand
what's going on.

If you've got scurvy, you want limes, not spare teeth.