net-p2p/libktorrent, fix with clang6

PR:		224945
Submitted by:	rakuco

net-p2p/libktorrent/Makefile

@@ -2,7 +2,7 @@
 
 PORTNAME=	libktorrent
 DISTVERSION=	1.3.1
-PORTREVISION=	14
+PORTREVISION=	15
 CATEGORIES=	net-p2p kde
 MASTER_SITES=	http://ktorrent.org/downloads/${DISTVERSION:C,^1,4,:C,-.*,,}/
 

net-p2p/libktorrent/files/patch-src_diskio_chunkmanager.cpp

@@ -0,0 +1,15 @@
+error: case value evaluates to -1, which cannot be narrowed to type 'unsigned int'
+    [-Wc++11-narrowing]
+                                case -1:
+
+--- src/diskio/chunkmanager.cpp.orig	2018-01-07 15:40:05 UTC
++++ src/diskio/chunkmanager.cpp
+@@ -528,7 +528,7 @@ namespace bt
+ 					tf.setPriority(EXCLUDED);
+ 					break;
+ 				case ONLY_SEED_PRIORITY:
+-				case -1:
++				case static_cast<Uint32>(-1):
+ 					tf.setPriority(ONLY_SEED_PRIORITY);
+ 					break;
+ 				default: