This patch was fed back to the upstream community:

http://code.google.com/p/libarchive/issues/detail?id=288

Given the response "This issue has been already fixed in master branch."

it should no longer be needed with the next release.

--- libarchive/libarchive/archive_string.c.orig	Mon Mar 26 19:49:00 2012

+++ libarchive/libarchive/archive_string.c	Tue Nov 27 18:10:35 2012

@@ -1120,8 +1120,8 @@

 	}

 	sc->to_charset = strdup(tc);

 	if (sc->to_charset == NULL) {

-		free(sc);

 		free(sc->from_charset);

+		free(sc);

 		return (NULL);

 	}

 	archive_string_init(&sc->utftmp);