Bug#401263: better backtrace

[Jan Evert van Grootheest <j.e.van.grootheest@caiway.nl>]

I've installed the newer 46.3 version and it also crashes.
However the backtrace is a bit more readable:

(gdb) bt
#0  0xb7d3b2f3 in strlen () from /lib/tls/i686/cmov/libc.so.6
#1  0xb7ebe316 in std::string::compare () from /usr/lib/libstdc++.so.6
#2  0xb7fb35d1 in debPackagesIndex::FindInCache () from 
/usr/lib/libapt-pkg-libc6.3-6.so.3.11
#3  0xb7f7bfdb in pkgCacheGenerator::~pkgCacheGenerator () from 
/usr/lib/libapt-pkg-libc6.3-6.so.3.11
#4  0xb7f7caed in pkgMakeStatusCache () from 
/usr/lib/libapt-pkg-libc6.3-6.so.3.11
#5  0xb7f73cff in pkgCacheFile::BuildCaches () from 
/usr/lib/libapt-pkg-libc6.3-6.so.3.11
#6  0x0805332e in ?? ()
#7  0xb7f4235b in CommandLine::DispatchArg () from 
/usr/lib/libapt-pkg-libc6.3-6.so.3.11
#8  0x0804f59f in ?? ()
#9  0xb7ce4ea8 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
#10 0x0804c5a1 in ?? ()