Invalid patches in traceroute-1.4a12-24.src.rpm at least
Just extracting the srpm and running the following:

grep "^Patch" ../traceroute.spec  |
cut -d: -f2 |
while read patch; do
    echo "****$patch****"
    patch --dry-run -ts -p1
done

gives:

****traceroute-1.4a5-fix.patch****
****traceroute-1.4a5-secfix.patch****
****traceroute-1.4a5-alpha.patch****
1 out of 1 hunk FAILED -- saving rejects to file linux-include/netinet/ip_var.h.rej
****traceroute-1.4a5-autoroute.patch****
1 out of 1 hunk FAILED -- saving rejects to file configure.rej
1 out of 1 hunk FAILED -- saving rejects to file configure.in.rej
****traceroute-1.4a5-autoroute2.patch****
1 out of 3 hunks FAILED -- saving rejects to file traceroute.c.rej
****traceroute-1.4a5-unaligned.patch****
****traceroute-1.4a5-llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch.patch****
****traceroute-1.4a5-fhs.patch****
1 out of 2 hunks FAILED -- saving rejects to file Makefile.in.rej
****traceroute-1.4a5-sourceroute.patch****
The text leading up to this was:
--------------------------
|--- traceroute-1.4a5/savestr.c.orig    Sat May 10 00:52:34 1997
|+++ traceroute-1.4a5/savestr.c Sat Jul  8 00:29:51 2000
--------------------------
No file to patch.  Skipping patch.
1 out of 1 hunk ignored
****traceroute-1.4a5-aliases.patch****
4 out of 4 hunks FAILED -- saving rejects to file traceroute.c.rej
****traceroute-1.4a5-droproot.patch****
****traceroute-1.4a5-bigpacklen.patch****
****traceroute-1.4a5-lsrr.patch****
1 out of 1 hunk FAILED -- saving rejects to file configure.rej
6 out of 22 hunks FAILED -- saving rejects to file traceroute.c.rej
****traceroute-1.4a12-sockopt.patch****
****traceroute-1.4a12-sockopt2.patch****
1 out of 1 hunk FAILED -- saving rejects to file traceroute.c.rej
****traceroute-1.4a12-tos-monitoring.patch****
****traceroute-1.4a12-mpls-icmp-02.patch****
****traceroute-1.4a12-pie.patch****

I've only tried traceroute, so perhaps this script should
be run over all packages?