(svn r2297) - CodeChange: server-check the next batch of commands.

- CodeChange: since only the server will be able to modify difficulty settings, leave the checking of correct values besides, and trust users will join legit servers.
- CodeChange: for renaming signs, only check if GetDParam(); eg _decode_parameters is empty ('\0') or not, instead of the extra check of players, etc. That basically does the same thing. Also dirty sign two times when renaming, once before, once after the action. Because if the name becomes shorter and you update only after, garbage remains on the screen.
- CodeChange: made GetMaskOfTownActions() available to the town-cmd to double-check if the action was available to the player. For this purpose the hardcoded _local_player has been removed from the function and is now passed as a parameter.

1 files changed, 43 insertions, 27 deletions

diff --git a/economy.c b/economy.c
index d77611f71..8e2c27f02 100644
--- a/economy.c
+++ b/economy.c
@@ -1527,41 +1527,40 @@ static void DoAcquireCompany(Player *p)
 
 extern int GetAmountOwnedBy(Player *p, byte owner);
 
+/** Acquire shares in an opposing company.
+ * @param x,y unused
+ * @param p1 player to buy the shares from
+ * @param p2 unused
+ */
 int32 CmdBuyShareInCompany(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 {
 	Player *p;
 	int64 cost;
-	byte *b;
-	int i;
+
+	/* Check if buying shares is allowed (protection against modified clients */
+	if (p1 >= MAX_PLAYERS || !_patches.allow_shares) return CMD_ERROR;
 
 	SET_EXPENSES_TYPE(EXPENSES_OTHER);
 	p = DEREF_PLAYER(p1);
 
-
-	if (_cur_year - p->inaugurated_year < 6) {
-		_error_message = STR_7080_PROTECTED;
-		return CMD_ERROR;
-	}
-
-	/* Check if buying shares is allowed (protection against modified clients */
-	if (!_patches.allow_shares)
-		return CMD_ERROR;
+	/* Protect new companies from hostile takeovers */
+	if (_cur_year - p->inaugurated_year < 6) return_cmd_error(STR_7080_PROTECTED);
 
 	/* Those lines are here for network-protection (clients can be slow) */
-	if (GetAmountOwnedBy(p, OWNER_SPECTATOR) == 0)
-		return 0;
+	if (GetAmountOwnedBy(p, OWNER_SPECTATOR) == 0) return 0;
 
-	/* We can not buy out a real player in networking */
-	if (GetAmountOwnedBy(p, OWNER_SPECTATOR) == 1 && !p->is_ai)
-		return 0;
+	/* We can not buy out a real player (temporarily). TODO: well, enable it obviously */
+	if (GetAmountOwnedBy(p, OWNER_SPECTATOR) == 1 && !p->is_ai) return 0;
 
 	cost = CalculateCompanyValue(p) >> 2;
 	if (flags & DC_EXEC) {
-		b = p->share_owners;
+		int i;
+		byte *b = p->share_owners;
+
 		while (*b != 0xFF) b++; /* share owners is guaranteed to contain at least one 0xFF */
 		*b = _current_player;
 
-		for(i=0;p->share_owners[i] == _current_player;) {
+		for (i = 0; p->share_owners[i] == _current_player;) {
 			if (++i == 4) {
 				p->bankrupt_value = 0;
 				DoAcquireCompany(p);
@@ -1573,29 +1572,31 @@ int32 CmdBuyShareInCompany(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	return cost;
 }
 
+/** Sell shares in an opposing company.
+ * @param x,y unused
+ * @param p1 player to sell the shares from
+ * @param p2 unused
+ */
 int32 CmdSellShareInCompany(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 {
 	Player *p;
 	int64 cost;
-	byte *b;
+
+	/* Check if buying shares is allowed (protection against modified clients */
+	if (p1 >= MAX_PLAYERS || !_patches.allow_shares) return CMD_ERROR;
 
 	SET_EXPENSES_TYPE(EXPENSES_OTHER);
 	p = DEREF_PLAYER(p1);
 
-	/* Check if selling shares is allowed (protection against modified clients */
-	if (!_patches.allow_shares)
-		return CMD_ERROR;
-
 	/* Those lines are here for network-protection (clients can be slow) */
-	if (GetAmountOwnedBy(p, _current_player) == 0)
-		return 0;
+	if (GetAmountOwnedBy(p, _current_player) == 0) return 0;
 
 	/* adjust it a little to make it less profitable to sell and buy */
 	cost = CalculateCompanyValue(p) >> 2;
 	cost = -(cost - (cost >> 7));
 
 	if (flags & DC_EXEC) {
-		b = p->share_owners;
+		byte *b = p->share_owners;
 		while (*b != _current_player) b++; /* share owners is guaranteed to contain player */
 		*b = 0xFF;
 		InvalidateWindow(WC_COMPANY, (int)p1);
@@ -1603,12 +1604,27 @@ int32 CmdSellShareInCompany(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	return cost;
 }
 
+/** Buy up another company.
+ * When a competing company is gone bankrupt you get the chance to purchase
+ * that company.
+ * @todo currently this only works for AI players
+ * @param x,y unused
+ * @param p1 player/company to buy up
+ * @param p2 unused
+ */
 int32 CmdBuyCompany(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 {
 	Player *p;
+
+	/* Disable takeovers in multiplayer games */
+	if (p1 >= MAX_PLAYERS || _networking) return CMD_ERROR;
+
 	SET_EXPENSES_TYPE(EXPENSES_OTHER);
 	p = DEREF_PLAYER(p1);
-	if (flags & 1) {
+
+	if (!p->is_ai) return CMD_ERROR;
+
+	if (flags & DC_EXEC) {
 		DoAcquireCompany(p);
 	}
 	return p->bankrupt_value;