Version 1.126 of proxy_util.c was created to fix bugs 10026 and 11668, and it does fix them. However, I feel that the fix introduced is wasteful in that it does a strlen followed by a ap_pstrcat, when a simple one-character check and one-character assignment is sufficient. I'll attach a patch showing the change I propose.
Created attachment 6217 [details] proxy_util.c patch
I'm going through the bug db to make sure patches are findable. Please see http://httpd.apache.org/dev/patches.html