added Debug-build NSAsserts to verify tiles requested are within legal zoom range

@@ -33,6 +33,9 @@
 
 -(NSString*) tileURL: (RMTile) tile
 {
+	NSAssert4(((tile.zoom >= self.minZoom) && (tile.zoom <= self.maxZoom)),
+			  @"%@ tried to retrieve tile with zoomLevel %d, outside source's defined range %f to %f", 
+			  self, tile.zoom, self.minZoom, self.maxZoom);
 	return [NSString stringWithFormat:@"http://a.tile.cloudmade.com/0199bdee456e59ce950b0156029d6934/2/%d/%d/%d/%d.png",[RMCloudMadeMapSource tileSideLength], tile.zoom, tile.x, tile.y];
 }
 

@@ -31,8 +31,15 @@
 
 -(NSString*) tileURL: (RMTile) tile
 {
+	NSAssert4(((tile.zoom >= self.minZoom) && (tile.zoom <= self.maxZoom)),
+			  @"%@ tried to retrieve tile with zoomLevel %d, outside source's defined range %f to %f", 
+			  self, tile.zoom, self.minZoom, self.maxZoom);
 	return [NSString stringWithFormat:@"http://tile.openaerialmap.org/tiles/1.0.0/openaerialmap-900913/%d/%d/%d.png", tile.zoom, tile.x, tile.y];
 }
 
+-(NSString*) description
+{
+	return @"OpenAerialMap";
+}
 
 @end

@@ -31,6 +31,9 @@
 
 -(NSString*) tileURL: (RMTile) tile
 {
+	NSAssert4(((tile.zoom >= self.minZoom) && (tile.zoom <= self.maxZoom)),
+			  @"%@ tried to retrieve tile with zoomLevel %d, outside source's defined range %f to %f", 
+			  self, tile.zoom, self.minZoom, self.maxZoom);
 	return [NSString stringWithFormat:@"http://tile.openstreetmap.org/%d/%d/%d.png", tile.zoom, tile.x, tile.y];
 }
 

@@ -38,6 +38,9 @@
 
 -(NSString*) quadKeyForTile: (RMTile) tile
 {
+	NSAssert4(((tile.zoom >= self.minZoom) && (tile.zoom <= self.maxZoom)),
+			  @"%@ tried to retrieve tile with zoomLevel %d, outside source's defined range %f to %f", 
+			  self, tile.zoom, self.minZoom, self.maxZoom);
 	NSMutableString *quadKey = [NSMutableString string];
 	for (int i = tile.zoom; i > 0; i--)
 	{

@@ -691,7 +691,9 @@
 				GCC_ENABLE_FIX_AND_CONTINUE = NO;
 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
 				GCC_PREFIX_HEADER = MapView_Prefix.pch;
-				GCC_PREPROCESSOR_DEFINITIONS = "DEBUG=0";
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"NS_BLOCK_ASSERTIONS=1",
+				);
 				HEADER_SEARCH_PATHS = ../Proj4;
 				PREBINDING = NO;
 				PRODUCT_NAME = MapView;

@@ -17,5 +17,6 @@
 
 #define RMLog(args...)    // do nothing.
 #define LogMethod() 
+#define NS_BLOCK_ASSERTIONS 1
 #endif