Squid-2.2.STABLE2: allow-miss cache_peer option
  allow-miss cache peer option to disable the use of "only-if-cached" on
  requests to siblings. This can be useful in some peering arrangements
  where icp_hit_stale is enabled.

Index: squid/src/cf.data.pre
diff -u squid/src/cf.data.pre:1.1.1.35.2.3 squid/src/cf.data.pre:1.1.1.35.2.4
--- squid/src/cf.data.pre:1.1.1.35.2.3	Wed May  5 11:33:48 1999
+++ squid/src/cf.data.pre	Fri May 14 00:15:55 1999
@@ -229,6 +229,7 @@
 		     no-delay
 		     login=user:password
 		     connect-timeout=nn
+		     allow-miss
 
 		     use 'proxy-only' to specify that objects fetched
 		     from this cache should not be saved locally.
@@ -279,6 +280,13 @@
 
 		     use 'connect-timeout=nn' to specify a peer specific
 		     connect timeout (see also peer_connect_timeout directive)
+
+		     use 'allow-miss' to disable Squid's use of only-if-cached
+		     when forwarding requests to siblings. This is primarily
+		     useful when icp_hit_stale is used by the sibling. To
+		     extensive use of this option may result in forwarding
+		     loops, and you should avoid having two-way peerings
+		     with this option.
 
 	NOTE: non-ICP neighbors must be specified as 'parent'.
 
Index: squid/src/structs.h
diff -u squid/src/structs.h:1.1.1.37.6.4 squid/src/structs.h:1.1.1.37.6.5
--- squid/src/structs.h:1.1.1.37.6.4	Sun May  9 07:50:44 1999
+++ squid/src/structs.h	Fri May 14 00:15:56 1999
@@ -1042,6 +1042,7 @@
 #if DELAY_POOLS
 	unsigned int no_delay:1;
 #endif
+	unsigned int allow_miss:1;
     } options;
     int weight;
     struct {
Index: squid/src/http.c
diff -u squid/src/http.c:1.1.1.32.6.1 squid/src/http.c:1.1.1.32.6.2
--- squid/src/http.c:1.1.1.32.6.1	Sun May  2 16:18:36 1999
+++ squid/src/http.c	Fri May 14 00:15:56 1999
@@ -842,7 +842,8 @@
     else if ((double) p->stats.n_keepalives_recv / (double) p->stats.n_keepalives_sent > 0.50)
 	httpState->flags.keepalive = 1;
     if (httpState->peer)
-	if (neighborType(httpState->peer, httpState->request) == PEER_SIBLING)
+	if (neighborType(httpState->peer, httpState->request) == PEER_SIBLING &&
+		!httpState->peer->options.allow_miss)
 	    httpState->flags.only_if_cached = 1;
     memBufDefInit(&mb);
     httpBuildRequestPrefix(req,
Index: squid/src/cache_cf.c
diff -u squid/src/cache_cf.c:1.1.1.29.4.2 squid/src/cache_cf.c:1.1.1.29.4.3
--- squid/src/cache_cf.c:1.1.1.29.4.2	Thu Apr 29 14:41:59 1999
+++ squid/src/cache_cf.c	Sat May 15 22:28:10 1999
@@ -1049,6 +1049,8 @@
 	    p->login = xstrdup(token + 6);
 	} else if (!strncasecmp(token, "connect-timeout=", 16)) {
 	    p->connect_timeout = atoi(token+16);
+	} else if (!strcasecmp(token, "allow-miss")) {
+	    p->options.allow_miss = 1;
 	} else {
 	    debug(3, 0) ("parse_peer: token='%s'\n", token);
 	    self_destruct();