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RE: libc5 to libc6: purge or install *-dev?

Þann 16-Nov-97 skrifar Jameson Burt:
> Your libc5-libc6-Mini-HOWTO.txt saves many people from ruinning their 
> operating systems.  A few changes could save a few more people.  When a
> person 
> ruins zher operating system by badly adding packages from hamm, zhe consumes 
> weeks of time.  You might save tens of people a hundred wasted hours each.
  That's a really good point, one that was needed...

  But *notice*, that it is also possible to break your system by
upgrading in unstable (hamm)...

  Here are two issues, from hamm.... Locales, when a program that is using
glibc does setlocale, it does not get it's locale information from the
localedata that comes with glibc (namely /usr/share/i18n/locales), but
rather takes it from the older libc5 localeinfo /usr/share/locales (not
that *that* really matters, but it raises a question as to wether *other*
functions in glibc have an _overrride_ value).

  Many Unix programs are really careless about memory allocations, now
many programs will get 'SIGSEGV' and break, and the error occurs inside
free(), as free is called with a stray pointer either from a library or
from the program... this is because glibc has runtime options that allows
well constructed programs to use malloc and have it fast, but also to set
it secure for other programs.  And a lot of libraries and programs aren't
well constructed... and the default is for malloc to be _fast_ :(

...and two issues concerning GNU C++,

  The C++ package in hamm is not compiled with setlocale functioning.  So,
if you do setlocale in your program, and then 'printf("%.2f", value)' your
value will not print "100,00" even if your decimal point is set to ','...
as it should do.

  And using 'malloc' inside a C++ program, will corrupt it and _may_ cause
it to SIGSEGV at some point...

Orn Einar Hansen                         oe.hansen@oehansen.pp.se
                                        voice+fax; +46 035 217194

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