From c817ab5ae0601a9bbdce6c36f7cdccff9fe7474b Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@debian.org>
Date: Sun, 19 May 2013 21:31:12 +0100
Subject: [PATCH] Find system zlib via user override, pkg-config or in standard
 locations

---
 Makefile | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index 416d1f17..1563d703 100644
--- a/Makefile
+++ b/Makefile
@@ -1028,11 +1028,13 @@ ifeq ($(USE_VOIP),1)
 endif
 
 ifeq ($(USE_INTERNAL_ZLIB),1)
-  BASE_CFLAGS += -DNO_GZIP
-  BASE_CFLAGS += -I$(ZDIR)
+  ZLIB_CFLAGS = -DNO_GZIP -I$(ZDIR)
 else
-  LIBS += -lz
+  ZLIB_CFLAGS ?= $(shell pkg-config --silence-errors --cflags zlib || true)
+  ZLIB_LIBS ?= $(shell pkg-config --silence-errors --libs zlib || echo -lz)
 endif
+BASE_CFLAGS += $(ZLIB_CFLAGS)
+LIBS += $(ZLIB_LIBS)
 
 ifeq ($(USE_INTERNAL_JPEG),1)
   BASE_CFLAGS += -DUSE_INTERNAL_JPEG