Security fixes for opensaml2 and xmltooling

[Florian Weimer]

* Scott Cantor:

> Florian Weimer wrote on 2009-09-23:
>> This touches a function implicitly declared inline.  We have to rebuild
>> all reverse build dependencies (direct and indirect) which instantiate
>> MetadataCredentialCriteria objects because each such compilation unit
>> has received a local copy of the function.  (There isn't any out-of-line
>> method in the class, so there is no compilation unit which contains the
>> class vtable and a master copy of that method.)
>
> AFAIK, virtual functions aren't inlined, period. If every object file had
> its own copy, the language would break.

If there's a single copy, it must be located in a particular .o file
after the build process.  Certainly, you can tell me which one it
is. 8-)

No, it's really as I said---every compilation unit receives its own
copy.  The linker has special support for throwing away duplicates.
Here's a short write-up, which seems to be reasonably up-to-date:

<http://gcc.gnu.org/onlinedocs/gcc-4.4.1/gcc/Vague-Linkage.html#Vague-Linkage>