dereferenced NULL in setup-2.529 (possible patch)

[mwoehlke]

Brian Dessent wrote:
> mwoehlke wrote:
> 
>> I built setup (from the 2.529 tarball) and ran it in gdb, and got this
>> stack trace:
> 
> Thanks for the debugging.  I must have missed the original report, as I
> don't see the parent post of this thread.  Under what circumstances is
> this repeatable?  It looks like the probable case is that
> get_url_to_string() is not able to fetch the URL of the mirrors list,
> and hence 'mirrors' is empty.

No, you probably didn't... the original report was buried in 
http://cygwin.com/ml/cygwin/2006-05/msg00074.html which didn't seem to 
get much reading, under "hmm, that's funny, now it's working". That was 
on my W2k3 R2 computer. Originally, I gave up trying to debug it because 
it seemed to be a fluke.

It isn't an empty mirror list problem, though; on my XP computer, it 
consistently blows up shortly /after/selecting/ a mirror, so your guess 
is about one step too early :-).

Anyway, I found something interesting... I was using 
http://mirrors.kernel.org when it blew up. If I use 
http://mirrors.mcs.anl.gov, then it's OK.

> As cgf alludes, the state of string handling in setup is currently quite
> a mess.  There is kind of a mix std::string, a homemade String class,
> and C strings.  We're trying to get rid of the homemade kind.
> 
> From looking at site.cc it seems that get_site_list() is in dire need of
> refactoring.  I think it would make things a lot simpler to just have
> load_site_list() take a string, and then process it using c_str(),
> skipping the whole new_cstr_char_array() mess.  It makes no sense to go
> and allocate something just to pass to load_site_list(), only to then
> free it.  And eventually everything in String++.{cc,h} needs to die
> anyway.
> 
> I will try to prepare a fix along these lines soon.

Ok, you know the code much better than I. :-) Meanwhile, it WFM with the 
patch in the previous message, so I'll just run that (or use a different 
mirror ;-)) until there is another snapshot or release.

p.s. What's the snapshot schedule for setup.exe... less often that 
cygwin1.dll, I take it?

-- 
Matthew
Interix, Sphinterix. Cygwin apps don't crash. :-)


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