fix build of postgresql with bundled zlib

Change-Id: I8a1a8b8e1437d79d4c262cb8521a1239c250699e

external/postgresql/ExternalProject_postgresql.mk

@@ -31,6 +31,10 @@ else
 postgresql_CPPFLAGS := $(ZLIB_CFLAGS)
 postgresql_LDFLAGS  :=
 
+ifeq ($(SYSTEM_ZLIB),)
+postgresql_LDFLAGS += $(ZLIB_LIBS)
+endif
+
 ifeq ($(DISABLE_OPENSSL),)
 ifeq ($(SYSTEM_OPENSSL),)
 postgresql_CPPFLAGS += -I$(call gb_UnpackedTarball_get_dir,openssl)/include

external/postgresql/UnpackedTarball_postgresql.mk

@@ -19,4 +19,10 @@ $(eval $(call gb_UnpackedTarball_add_patches,postgresql, \
 	external/postgresql/postgresql-9.2.1-libreoffice.patch \
 ))
 
+ifeq ($(SYSTEM_ZLIB),)
+$(eval $(call gb_UnpackedTarball_add_patches,postgresql, \
+	external/postgresql/internal-zlib.patch.1 \
+))
+endif
+
 # vim: set noet sw=4 ts=4:

external/postgresql/internal-zlib.patch.1

+diff -up postgresql/configure.dt postgresql/configure
+--- postgresql/configure.dt	2016-11-03 17:34:17.282388226 +0100
++++ postgresql/configure	2016-11-03 17:34:35.004202484 +0100
+@@ -8566,13 +8566,13 @@ fi
+ 
+ if test "$with_zlib" = yes; then
+ 
+-{ $as_echo "$as_me:$LINENO: checking for inflate in -lz" >&5
+-$as_echo_n "checking for inflate in -lz... " >&6; }
++{ $as_echo "$as_me:$LINENO: checking for inflate in -lzlib" >&5
++$as_echo_n "checking for inflate in -lzlib... " >&6; }
+ if test "${ac_cv_lib_z_inflate+set}" = set; then
+   $as_echo_n "(cached) " >&6
+ else
+   ac_check_lib_save_LIBS=$LIBS
+-LIBS="-lz  $LIBS"
++LIBS="-lzlib  $LIBS"
+ cat >conftest.$ac_ext <<_ACEOF
+ /* confdefs.h.  */
+ _ACEOF
+@@ -8636,7 +8636,7 @@ if test "x$ac_cv_lib_z_inflate" = x""yes
+ #define HAVE_LIBZ 1
+ _ACEOF
+ 
+-  LIBS="-lz $LIBS"
++  LIBS="-lzlib $LIBS"
+ 
+ else
+   { { $as_echo "$as_me:$LINENO: error: zlib library not found