This patch fixes a possible crash caused by a missing null pointer check, see Gentoo bug 277845.
This fixes compilation on Ruby 1.9 (see GitHub issue 1). Thanks to Lennart for spotting it.
It was i386-mswin32 before, but it seems you should use x86-mswin32-60 these days (as seen on the index at gems.rubyforge.org).
When compiling the extension under the MinGW-based One-Click Installer environment, we also want to download and compile id3lib first (the same as with cross compiling). This should make id3lib-ruby work without problems with the MinGW One-Click Installer.