--- a/src/economy.cpp	Thu Apr 19 14:48:10 2007 +0000
+++ b/src/economy.cpp	Tue Jun 12 11:56:35 2007 +0000
@@ -6,6 +6,7 @@
 #include "openttd.h"
 #include "currency.h"
 #include "functions.h"
+#include "landscape.h"
 #include "strings.h" // XXX InjectDParam()
 #include "table/strings.h"
 #include "table/sprites.h"
@@ -254,6 +255,41 @@
 {
 	Town *t;
 	PlayerID old = _current_player;
+
+	assert(old_player != new_player);
+
+	{
+		Player *p;
+		uint i;
+
+		/* See if the old_player had shares in other companies */
+		_current_player = old_player;
+		FOR_ALL_PLAYERS(p) {
+			for (i = 0; i < 4; i++) {
+				if (p->share_owners[i] == old_player) {
+					/* Sell his shares */
+					int32 res = DoCommand(0, p->index, 0, DC_EXEC, CMD_SELL_SHARE_IN_COMPANY);
+					/* Because we are in a DoCommand, we can't just execute an other one and
+					 *  expect the money to be removed. We need to do it ourself! */
+					SubtractMoneyFromPlayer(res);
+				}
+			}
+		}
+
+		/* Sell all the shares that people have on this company */
+		p = GetPlayer(old_player);
+		for (i = 0; i < 4; i++) {
+			_current_player = p->share_owners[i];
+			if (_current_player != PLAYER_SPECTATOR) {
+				/* Sell the shares */
+				int32 res = DoCommand(0, old_player, 0, DC_EXEC, CMD_SELL_SHARE_IN_COMPANY);
+				/* Because we are in a DoCommand, we can't just execute an other one and
+				 *  expect the money to be removed. We need to do it ourself! */
+				SubtractMoneyFromPlayer(res);
+			}
+		}
+	}
+
 	_current_player = old_player;
 
 	/* Temporarily increase the player's money, to be sure that
@@ -346,25 +382,6 @@
 	/* Change color of existing windows */
 	if (new_player != PLAYER_SPECTATOR) ChangeWindowOwner(old_player, new_player);
 
-	{
-		Player *p;
-		uint i;
-
-		/* Check for shares */
-		FOR_ALL_PLAYERS(p) {
-			for (i = 0; i < 4; i++) {
-				/* 'Sell' the share if this player has any */
-				if (p->share_owners[i] == _current_player) {
-					p->share_owners[i] = PLAYER_SPECTATOR;
-				}
-			}
-		}
-		p = GetPlayer(_current_player);
-		/* Sell all the shares that people have on this company */
-		for (i = 0; i < 4; i++)
-			p->share_owners[i] = PLAYER_SPECTATOR;
-	}
-
 	_current_player = old;
 
 	MarkWholeScreenDirty();
@@ -965,6 +982,23 @@
 	const CargoSpec *cs = GetCargo(cargo_type);
 	byte f;
 
+	/* Use callback to calculate cargo profit, if available */
+	if (HASBIT(cs->callback_mask, CBM_CARGO_PROFIT_CALC)) {
+		uint32 var18 = min(dist, 0xFFFF) | (min(num_pieces, 0xFF) << 16) | (transit_days << 24);
+		uint16 callback = GetCargoCallback(CBID_CARGO_PROFIT_CALC, 0, var18, cs);
+		if (callback != CALLBACK_FAILED) {
+			int result = GB(callback, 0, 14);
+
+			/* Simulate a 15 bit signed value */
+			if (HASBIT(callback, 14)) result = 0x4000 - result;
+
+			/* "The result should be a signed multiplier that gets multiplied
+			 * by the amount of cargo moved and the price factor, then gets
+			 * divided by 8192." */
+			return result * num_pieces * _cargo_payment_rates[cargo_type] / 8192;
+		}
+	}
+
 	/* zero the distance if it's the bank and very short transport. */
 	if (_opt.landscape == LT_TEMPERATE && cs->label == 'VALU' && dist < 10)
 		dist = 0;
@@ -1520,6 +1554,7 @@
 
 /** Acquire shares in an opposing company.
  * @param tile unused
+ * @param flags type of operation
  * @param p1 player to buy the shares from
  * @param p2 unused
  */
@@ -1565,6 +1600,7 @@
 
 /** Sell shares in an opposing company.
  * @param tile unused
+ * @param flags type of operation
  * @param p1 player to sell the shares from
  * @param p2 unused
  */
@@ -1600,18 +1636,23 @@
  * that company.
  * @todo currently this only works for AI players
  * @param tile unused
+ * @param flags type of operation
  * @param p1 player/company to buy up
  * @param p2 unused
  */
 int32 CmdBuyCompany(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 {
 	Player *p;
+	PlayerID pid = (PlayerID)p1;
 
 	/* Disable takeovers in multiplayer games */
-	if (!IsValidPlayer((PlayerID)p1) || _networking) return CMD_ERROR;
+	if (!IsValidPlayer(pid) || _networking) return CMD_ERROR;
+
+	/* Do not allow players to take over themselves */
+	if (pid == _current_player) return CMD_ERROR;
 
 	SET_EXPENSES_TYPE(EXPENSES_OTHER);
-	p = GetPlayer((PlayerID)p1);
+	p = GetPlayer(pid);
 
 	if (!p->is_ai) return CMD_ERROR;