Before installing the new packages (glibc-2.2-12) I looked at the package sizes. The new packages are 4Mb while the original was 9Mb and the latest update before this one even 13Mb. I don't trust this new update and will only install after a statement that it is safe and bugfree. Normally such size changes are implying big changes. But I can hardly believe such things for an established package as the C-Library.. ps. this is filed as a bug for there is no other appearent way to ask these questions, and if it turns out a bug it could have disastrous consequences.
The former glibc package was split into glibc and glibc-common (the reason behind this is to save space, because glibc-common can be shared between e.g. i386 and i686, alpha and alphaev6, sparc and sparcv9). glibc-2.2-9.i386.rpm was ~13M, glibc-2.2-12.i386.rpm is ~4.5M and glibc-common-2.2-12.i386.rpm is ~6M, so the actual size difference is not that big and is caused by hardlinking identical /usr/lib/locale/ data files between various locales (that saved ~20M in the installed size and ~2.5M in the rpm).
Oh, one more thing, if you want to install a bugfree glibc, I'm afraid you'll have to wait forever, software package of this size will never be bugfree. I can just assure you this package was tested by myself and our QA and seems to be ok.
Who was talking about bugfree software? I don't expect bugfree software, because there is no such thing as bugfree software. It performs okay, but software is never finished and will always run in to bugs somewhere up the road. Just being cautious with software updates for some of my systems.