diff --git a/client/shaders/nodes_shader/opengl_fragment.glsl b/client/shaders/nodes_shader/opengl_fragment.glsl
index 49befa8d..6862842a 100644
--- a/client/shaders/nodes_shader/opengl_fragment.glsl
+++ b/client/shaders/nodes_shader/opengl_fragment.glsl
@@ -194,7 +194,7 @@ void main(void)
 
 	vec4 col = vec4(color.rgb * gl_Color.rgb, 1.0); 
 	
-#if MATERIAL_TYPE == TILE_MATERIAL_LIQUID_TRANSPARENT || MATERIAL_TYPE == TILE_MATERIAL_LIQUID_OPAQUE
+#if MATERIAL_TYPE == TILE_MATERIAL_LIQUID_TRANSPARENT
 	float alpha = gl_Color.a;
 	if (fogDistance != 0.0) {
 		float d = max(0.0, min(vPosition.z / fogDistance * 1.5 - 0.6, 1.0));
diff --git a/src/mg_ore.cpp b/src/mg_ore.cpp
index f519f9f4..33a9725c 100644
--- a/src/mg_ore.cpp
+++ b/src/mg_ore.cpp
@@ -179,7 +179,12 @@ void OreSheet::generate(MMVManip *vm, int mapseed, u32 blockseed,
 	MapNode n_ore(c_ore, 0, ore_param2);
 
 	u16 max_height = column_height_max;
-	int y_start = pr.range(nmin.Y + max_height, nmax.Y - max_height);
+	int y_start_min = nmin.Y + max_height;
+	int y_start_max = nmax.Y - max_height;
+
+	int y_start = y_start_min < y_start_max ?
+		pr.range(y_start_min, y_start_max) :
+		(y_start_min + y_start_max) / 2;
 
 	if (!noise) {
 		int sx = nmax.X - nmin.X + 1;
@@ -204,10 +209,10 @@ void OreSheet::generate(MMVManip *vm, int mapseed, u32 blockseed,
 
 		u16 height = pr.range(column_height_min, column_height_max);
 		int ymidpoint = y_start + noiseval;
-		int y0 = ymidpoint - height * (1 - column_midpoint_factor);
-		int y1 = y0 + height;
+		int y0 = MYMAX(nmin.Y, ymidpoint - height * (1 - column_midpoint_factor));
+		int y1 = MYMIN(nmax.Y, y0 + height - 1);
 
-		for (int y = y0; y < y1; y++) {
+		for (int y = y0; y <= y1; y++) {
 			u32 i = vm->m_area.index(x, y, z);
 			if (!vm->m_area.contains(i))
 				continue;
diff --git a/src/network/serverpackethandler.cpp b/src/network/serverpackethandler.cpp
index 7d179b56..b11de0fe 100644
--- a/src/network/serverpackethandler.cpp
+++ b/src/network/serverpackethandler.cpp
@@ -762,14 +762,14 @@ void Server::handleCommand_GotBlocks(NetworkPacket* pkt)
 
 	RemoteClient *client = getClient(pkt->getPeerId());
 
-	for (u16 i = 0; i < count; i++) {
-		if ((s16)pkt->getSize() < 1 + (i + 1) * 6)
-			throw con::InvalidIncomingDataException
+	if ((s16)pkt->getSize() < 1 + (int)count * 6) {
+		throw con::InvalidIncomingDataException
 				("GOTBLOCKS length is too short");
+	}
+
+	for (u16 i = 0; i < count; i++) {
 		v3s16 p;
-
 		*pkt >> p;
-
 		client->GotBlock(p);
 	}
 }
@@ -865,13 +865,14 @@ void Server::handleCommand_DeletedBlocks(NetworkPacket* pkt)
 
 	RemoteClient *client = getClient(pkt->getPeerId());
 
-	for (u16 i = 0; i < count; i++) {
-		if ((s16)pkt->getSize() < 1 + (i + 1) * 6)
-			throw con::InvalidIncomingDataException
+	if ((s16)pkt->getSize() < 1 + (int)count * 6) {
+		throw con::InvalidIncomingDataException
 				("DELETEDBLOCKS length is too short");
+	}
+
+	for (u16 i = 0; i < count; i++) {
 		v3s16 p;
 		*pkt >> p;
-
 		client->SetBlockNotSent(p);
 	}
 }