Applying patch EJAB-305 - Allow multiple entry with same nick to MUC rooms to version 2.1.6

I need multiple users with the same nickname and using different resources to be able to log in to a MUC simultaneously. I found the patch [EJAB-305] in the svn repository but, when I try to apply it to mod_muc_room.erl (cloned with git), I get a lot of failed Hunks:

patch -p2 < mod_muc_room.erl.patch --dry-run
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:
--------------------------
|diff --git a/src/mod_muc/mod_muc_room.erl b/src/mod_muc/mod_muc_room.erl
|index 47b40f6..0337f40 100644
|--- a/src/mod_muc/mod_muc_room.erl
|+++ b/src/mod_muc/mod_muc_room.erl
--------------------------
File to patch: mod_muc_room.erl
patching file mod_muc_room.erl
Hunk #1 succeeded at 958 with fuzz 2 (offset 65 lines).
Hunk #2 succeeded at 1277 with fuzz 1 (offset 105 lines).
Hunk #3 succeeded at 1481 with fuzz 1 (offset 105 lines).
Hunk #4 succeeded at 1505 with fuzz 1 (offset 105 lines).
Hunk #5 FAILED at 1461.
Hunk #6 FAILED at 1485.
Hunk #7 FAILED at 1497.
Hunk #8 FAILED at 1822.
Hunk #9 succeeded at 2007 (offset 134 lines).
Hunk #10 succeeded at 2044 with fuzz 1 (offset 136 lines).
Hunk #11 succeeded at 2062 (offset 137 lines).
Hunk #12 FAILED at 1999.
Hunk #13 succeeded at 3498 with fuzz 2 (offset 205 lines).
5 out of 13 hunks FAILED -- saving rejects to file mod_muc_room.erl.rej
can't find file to patch at input line 322
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:
--------------------------
|diff --git a/src/mod_muc/mod_muc_room.hrl b/src/mod_muc/mod_muc_room.hrl
|index 2ff1c18..9eb9077 100644
|--- a/src/mod_muc/mod_muc_room.hrl
|+++ b/src/mod_muc/mod_muc_room.hrl
--------------------------
File to patch: mod_muc_room.hrl
patching file mod_muc_room.hrl

My question is, can this patch be applied to version 2.1.6?
If so, how do you recommend I do so?
If not, how do I resolve the issue without creating a lot of messy nicknames? (Currently my rooms are set to not allow users to change their handles.)

Note: Using clients iChat, Pidgin, BeeJive.

Thanks for any help or advice!