2.4.x patch: http://people.apache.org/~jorton/ap_proxyblock-24x-v1.diff [avoids major MMN bump]
+1: jorton,
+ * mod_proxy: fix ProxyPassReverse for balancer configs, PR 45434 regression
+ trunk patch: http://svn.apache.org/viewvc?rev=1365479&view=rev
+ 2.4.x patch: trunk patch works
+ +1: jorton,
+
A list of further possible backports can be found at:
http://people.apache.org/~rjung/patches/possible-backports-httpd-trunk-2_4.txt
If you want to propose one of those, please still add them here.