Trouble installing Asterisk update

I’m having trouble installing a .diff patch to my Asterisk and am not sure how to make it work. I’m new to Asterisk and the first task I have been given is to update it. The version that I’m using is Asterisk 1.8.15-cert2 and I’m trying to upgrade it to Asterisk 1.8.15-cert5 ( … .8.15.diff). I copy the file to /usr/src/asterisk-gui-2.1.0-rcl (only Asterisk directory in /src folder), and run the command:

It then says the following:

[quote]can’t find file to patch at input line 5
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:

|Index: channels/chan_sip.c
|—Index: channels/chan_sip.c [revision 397753]

+++Index: channels/chan_sip.c [revision 397754]

File to patch:

The URL that directed me to the patch was … -2014-2286, and they said that the problem is because of “main/http.c,” but I can’t find http.c anywhere in my /src directory. What do I need to do to solve this problem? Thanks in advance!

main/http.c certainly exists relative to the top of the source tree, so, if you can’t find it, you presumably don’t have the whole Asterisk source tree.