diff -up pidgin-2.6.6/libpurple/protocols/msn/msg.c.CVE-2012-2318 pidgin-2.6.6/libpurple/protocols/msn/msg.c
--- pidgin-2.6.6/libpurple/protocols/msn/msg.c.CVE-2012-2318	2010-02-16 04:34:06.000000000 -0500
+++ pidgin-2.6.6/libpurple/protocols/msn/msg.c	2012-07-04 11:07:16.150396321 -0400
@@ -348,14 +348,48 @@ msn_message_parse_payload(MsnMessage *ms
 			memcpy(msg->body, tmp, msg->body_len);
 			msg->body[msg->body_len] = '\0';
 		}
-		
-		if ((!content_type || !strcmp(content_type, "text/plain"))
-			&& msg->charset == NULL) {
-			char *body = g_convert(msg->body, msg->body_len, "UTF-8",
-			                       "ISO-8859-1", NULL, &msg->body_len, NULL);
-			g_free(msg->body);
-			msg->body = body;
-			msg->charset = g_strdup("UTF-8");
+
+		if (msg->body && content_type && purple_str_has_prefix(content_type, "text/")) {
+			char *body = NULL;
+
+			if (msg->charset == NULL || g_str_equal(msg->charset, "UTF-8")) {
+				/* Charset is UTF-8 */
+				if (!g_utf8_validate(msg->body, msg->body_len, NULL)) {
+					purple_debug_warning("msn", "Message contains invalid "
+							"UTF-8. Attempting to salvage.\n");
+					body = purple_utf8_salvage(msg->body);
+					payload_len = strlen(body);
+				}
+			} else {
+				/* Charset is something other than UTF-8 */
+				GError *err = NULL;
+				body = g_convert(msg->body, msg->body_len, "UTF-8",
+						msg->charset, NULL, &payload_len, &err);
+				if (!body || err) {
+					purple_debug_warning("msn", "Unable to convert message from "
+							"%s to UTF-8: %s\n", msg->charset,
+							err ? err->message : "Unknown error");
+					if (err)
+						g_error_free(err);
+
+					/* Fallback to ISO-8859-1 */
+					g_free(body);
+					body = g_convert(msg->body, msg->body_len, "UTF-8",
+							"ISO-8859-1", NULL, &payload_len, NULL);
+					if (!body) {
+						g_free(msg->body);
+						msg->body = NULL;
+						msg->body_len = 0;
+					}
+				}
+			}
+
+			if (body) {
+				g_free(msg->body);
+				msg->body = body;
+				msg->body_len = payload_len;
+				msn_message_set_charset(msg, "UTF-8");
+			}
 		}
 	}