(svn r22390) [1.1] -Backport from trunk:

- Fix: When drawing the town authority window, check whether the availability of the actions changed, and force a complete redraw in that case (r22307)
- Fix: The 'freeform edges' setting could be enabled when there were buoys on the northern border [FS#4580] (r22297)
- Fix: Reset Window::scrolling_scrollbar when raising scrollbar buttons [FS#4571] (r22294)
- Fix: [NewGRF] the c and p parts of station vars 40, 41 and 49 were incorrect for large stations (r22286)

src/newgrf_station.cpp

@@ -110,24 +110,21 @@ uint32 GetPlatformInfo(Axis axis, byte tile, int platforms, int length, int x, i
 		Swap(x, y);
 	}
 
-	/* Limit our sizes to 4 bits */
-	platforms = min(15, platforms);
-	length    = min(15, length);
-	x = min(15, x);
-	y = min(15, y);
 	if (centred) {
 		x -= platforms / 2;
 		y -= length / 2;
+		x = Clamp(x, -8, 7);
+		y = Clamp(x, -8, 7);
 		SB(retval,  0, 4, y & 0xF);
 		SB(retval,  4, 4, x & 0xF);
 	} else {
-		SB(retval,  0, 4, y);
-		SB(retval,  4, 4, length - y - 1);
-		SB(retval,  8, 4, x);
-		SB(retval, 12, 4, platforms - x - 1);
+		SB(retval,  0, 4, min(15, y));
+		SB(retval,  4, 4, min(15, length - y - 1));
+		SB(retval,  8, 4, min(15, x));
+		SB(retval, 12, 4, min(15, platforms - x - 1));
 	}
-	SB(retval, 16, 4, length);
-	SB(retval, 20, 4, platforms);
+	SB(retval, 16, 4, min(15, length));
+	SB(retval, 20, 4, min(15, platforms));
 	SB(retval, 24, 4, tile);
 
 	return retval;

src/settings.cpp

@@ -1071,13 +1071,15 @@ static bool CheckFreeformEdges(int32 p1)
 	if (p1 != 0) {
 		Ship *s;
 		FOR_ALL_SHIPS(s) {
+			/* Check if there is a ship on the northern border. */
 			if (TileX(s->tile) == 0 || TileY(s->tile) == 0) {
 				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_EMPTY, INVALID_STRING_ID, WL_ERROR);
 				return false;
 			}
 		}
-		Station *st;
-		FOR_ALL_STATIONS(st) {
+		BaseStation *st;
+		FOR_ALL_BASE_STATIONS(st) {
+			/* Check if there is a buoy on the northern border. */
 			if (TileX(st->xy) == 0 || TileY(st->xy) == 0) {
 				ShowErrorMessage(STR_CONFIG_SETTING_EDGES_NOT_EMPTY, INVALID_STRING_ID, WL_ERROR);
 				return false;

src/town_gui.cpp

@@ -73,6 +73,7 @@ private:
 	Town *town;    ///< Town being displayed.
 	int sel_index; ///< Currently selected town action, \c 0 to \c TACT_COUNT-1, \c -1 means no action selected.
 	Scrollbar *vscroll;
+	uint displayed_actions_on_previous_painting; ///< Actions that were available on the previous call to OnPaint()
 
 	/**
 	 * Get the position of the Nth set bit.
@@ -96,7 +97,7 @@ private:
 	}
 
 public:
-	TownAuthorityWindow(const WindowDesc *desc, WindowNumber window_number) : Window(), sel_index(-1)
+	TownAuthorityWindow(const WindowDesc *desc, WindowNumber window_number) : Window(), sel_index(-1), displayed_actions_on_previous_painting(0)
 	{
 		this->town = Town::Get(window_number);
 		this->InitNested(desc, window_number);
@@ -108,6 +109,8 @@ public:
 	{
 		int numact;
 		uint buttons = GetMaskOfTownActions(&numact, _local_company, this->town);
+		if (buttons != displayed_actions_on_previous_painting) this->SetDirty();
+		displayed_actions_on_previous_painting = buttons;
 
 		this->vscroll->SetCount(numact + 1);
 

src/window.cpp

@@ -1392,6 +1392,7 @@ static void DecreaseWindowCounters()
 					NWidgetScrollbar *sb = static_cast<NWidgetScrollbar*>(nwid);
 					if (sb->disp_flags & (ND_SCROLLBAR_UP | ND_SCROLLBAR_DOWN)) {
 						sb->disp_flags &= ~(ND_SCROLLBAR_UP | ND_SCROLLBAR_DOWN);
+						w->scrolling_scrollbar = -1;
 						sb->SetDirty(w);
 					}
 				}