Index: common/diptreaty.h
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/diptreaty.h,v
retrieving revision 1.10
diff -u -r1.10 diptreaty.h
--- common/diptreaty.h	17 Apr 2003 20:06:36 -0000	1.10
+++ common/diptreaty.h	10 May 2003 21:13:42 -0000
@@ -18,7 +18,7 @@
 enum clause_type { CLAUSE_ADVANCE, CLAUSE_GOLD, CLAUSE_MAP,
 		   CLAUSE_SEAMAP, CLAUSE_CITY, 
 		   CLAUSE_CEASEFIRE, CLAUSE_PEACE, CLAUSE_ALLIANCE,
-		   CLAUSE_VISION};
+		   CLAUSE_VISION, CLAUSE_LAST };
 
 #define is_pact_clause(x) \
   ((x == CLAUSE_CEASEFIRE) || (x == CLAUSE_PEACE) || (x == CLAUSE_ALLIANCE))
Index: common/player.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/player.c,v
retrieving revision 1.117
diff -u -r1.117 player.c
--- common/player.c	18 Apr 2003 10:08:53 -0000	1.117
+++ common/player.c	10 May 2003 21:13:42 -0000
@@ -36,6 +36,29 @@
 #include "player.h"
 
 /***************************************************************
+  Returns true iff p1 can ally p2. There is only one condition:
+  We are not at war with any of p2's allies. Note that for an
+  alliance to be made, we need to check this both ways.
+
+  The reason for this is to avoid the dread 'love-love-hate' 
+  triad, in which p1 is allied to p2 is allied to p3 is at
+  war with p1. These lead to strange situations.
+***************************************************************/
+bool pplayer_can_ally(struct player *p1, struct player *p2)
+{
+  players_iterate(pplayer) {
+    if (pplayers_allied(p2, pplayer)
+        && pplayers_at_war(p1, pplayer)
+        && pplayer != p1
+        && pplayer != p2
+        && pplayer->is_alive) {
+      return FALSE;
+    }
+  } players_iterate_end;
+  return TRUE;
+}
+
+/***************************************************************
   Check if pplayer has an embassy with pplayer2. We always have
   an embassy with ourselves.
 ***************************************************************/
Index: common/player.h
===================================================================
RCS file: /home/freeciv/CVS/freeciv/common/player.h,v
retrieving revision 1.98
diff -u -r1.98 player.h
--- common/player.h	17 Apr 2003 20:06:36 -0000	1.98
+++ common/player.h	10 May 2003 21:13:42 -0000
@@ -255,6 +255,8 @@
 						     *pplayer,
 						     const struct player
 						     *pplayer2);
+
+bool pplayer_can_ally(struct player *p1, struct player *p2);
 bool pplayers_at_war(const struct player *pplayer,
 		    const struct player *pplayer2);
 bool pplayers_allied(const struct player *pplayer,
Index: server/diplhand.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/server/diplhand.c,v
retrieving revision 1.69
diff -u -r1.69 diplhand.c
--- server/diplhand.c	30 Apr 2003 21:14:35 -0000	1.69
+++ server/diplhand.c	10 May 2003 21:13:42 -0000
@@ -181,6 +181,15 @@
 	    return;
 	  }
 	  break;
+	case CLAUSE_ALLIANCE:
+          if (!pplayer_can_ally(pplayer, other)) {
+	    notify_player(pplayer,
+			  _("Game: You are at war with one of %s's "
+			    "allies - an alliance with %s is impossible."),
+			  other->name, other->name);
+            return;
+          }
+          break;
 	case CLAUSE_GOLD:
 	  if (pplayer->economic.gold < pclause->value) {
 	    notify_player(pplayer,
@@ -263,6 +272,19 @@
 	    goto cleanup;
 	  }
 	  break;
+	case CLAUSE_ALLIANCE:
+          if (!pplayer_can_ally(other, pplayer)) {
+	    notify_player(pplayer,
+			  _("Game: %s is at war with one of your "
+			    "allies - an alliance with %s is impossible."),
+			  other->name, other->name);
+	    notify_player(other,
+			  _("Game: You are at war with one of %s's "
+			    "allies - an alliance with %s is impossible."),
+			  pplayer->name, pplayer->name);
+	    goto cleanup;
+          }
+          break;
 	case CLAUSE_GOLD:
 	  if (other->economic.gold < pclause->value) {
 	    notify_player(plr0,
@@ -397,6 +419,9 @@
 			 _("Game: %s gives you shared vision."),
 			 pgiver->name);
 	break;
+      case CLAUSE_LAST:
+        freelog(LOG_ERROR, "Received bad clause type");
+        break;
       }
 
     } clause_list_iterate_end;
Index: server/plrhand.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/server/plrhand.c,v
retrieving revision 1.271
diff -u -r1.271 plrhand.c
--- server/plrhand.c	10 May 2003 19:20:16 -0000	1.271
+++ server/plrhand.c	10 May 2003 21:13:42 -0000
@@ -800,6 +800,12 @@
 
 /**************************************************************************
   Handles a player cancelling a "pact" with another player.
+
+  packet.id is id of player we want to cancel a pact with
+  packet.val1 is a special value indicating what kind of treaty we want
+    to break. If this is CLAUSE_VISION we break shared vision. If it is
+    a pact treaty type, we break one pact level. If it is CLAUSE_LAST
+    we break _all_ treaties and go straight to war.
 **************************************************************************/
 void handle_player_cancel_pact(struct player *pplayer,
                                struct packet_generic_values *packet)
@@ -808,7 +814,7 @@
   enum diplstate_type new_type;
   struct player *pplayer2;
   int reppenalty = 0;
-  bool has_senate;
+  bool has_senate, repeat = FALSE;
   int other_player = packet->id;
   int clause = packet->value1;
 
@@ -842,6 +848,7 @@
 
   /* else, breaking a treaty */
 
+repeat_break_treaty:
   /* check what the new status will be, and what will happen to our
      reputation */
   switch(old_type) {
@@ -869,10 +876,11 @@
   /* if there's a reason to cancel the pact, do it without penalty */
   if (pplayer->diplstates[pplayer2->player_no].has_reason_to_cancel > 0) {
     pplayer->diplstates[pplayer2->player_no].has_reason_to_cancel = 0;
-    if (has_senate)
+    if (has_senate && !repeat) {
       notify_player(pplayer, _("The senate passes your bill because of the "
 			       "constant provocations of the %s."),
 		    get_nation_name_plural(pplayer2->nation));
+    }
   }
   /* no reason to cancel, apply penalty (and maybe suffer a revolution) */
   /* FIXME: according to civII rules, republics and democracies
@@ -882,7 +890,7 @@
     pplayer->reputation = MAX(pplayer->reputation - reppenalty, 0);
     notify_player(pplayer, _("Game: Your reputation is now %s."),
 		  reputation_text(pplayer->reputation));
-    if (has_senate) {
+    if (has_senate && pplayer->revolution == 0) {
       if (myrand(GAME_MAX_REPUTATION) > pplayer->reputation) {
 	notify_player(pplayer, _("Game: The senate decides to dissolve "
 				 "rather than support your actions any longer."));
@@ -899,6 +907,15 @@
     pplayer2->diplstates[pplayer->player_no].turns_left =
     16;
 
+  /* We want to go all the way to war, whatever the cost! 
+   * This is only used when declaring war against an alliance 
+   * and by the AI. */
+  if (clause == CLAUSE_LAST && new_type != DS_WAR) {
+    repeat = TRUE;
+    old_type = new_type;
+    goto repeat_break_treaty;
+  }
+
   send_player_info(pplayer, NULL);
   send_player_info(pplayer2, NULL);
 
@@ -928,6 +945,22 @@
 		   get_nation_name_plural(pplayer2->nation),
 		   get_nation_name_plural(pplayer->nation),
 		   diplstate_text(new_type));
+
+  /* Check fall-out of a war declaration. */
+  players_iterate(other) {
+    if (other->is_alive && other != pplayer && other != pplayer2
+        && (pplayer->team == TEAM_NONE || pplayer->team != pplayer2->team)
+        && new_type == DS_WAR && pplayers_allied(pplayer2, other)
+        && !pplayers_at_war(pplayer, other)) {
+      struct packet_generic_values packet;
+
+      /* A declaration of war by A against B also means A declares
+       * war against all of B's allies. Yes, A gets the blame. */
+      packet.id = other->player_no;
+      packet.value1 = CLAUSE_LAST;
+      handle_player_cancel_pact(pplayer, &packet);
+    }
+  } players_iterate_end;
 }
 
 /**************************************************************************