$NetBSD: patch-unix_Makefile.gtk,v 1.4 2021/07/24 14:54:08 ryoon Exp $

Allow adding CFLAGS from the pkgsrc environment.
Use pkgsrc infrastructure for deciding on whether to link against libdl or not.
pow(3) requires libm.

--- unix/Makefile.gtk.orig	2021-07-10 09:47:57.000000000 +0000
+++ unix/Makefile.gtk
@@ -104,14 +104,14 @@ GTK_CONFIG = sh -c 'pkg-config gtk+-3.0 
 
 unexport CFLAGS # work around a weird issue with krb5-config
 
-CFLAGS = -O2 -Wall -std=gnu99 -Wvla -g -I.././ -I../charset/ -I../windows/ \
+CFLAGS += -O2 -Wall -std=gnu99 -Wvla -g -I.././ -I../charset/ -I../windows/ \
 		-I../unix/ $(shell $(GTK_CONFIG) --cflags) -D _FILE_OFFSET_BITS=64
 XLDFLAGS = $(LDFLAGS) $(shell $(GTK_CONFIG) --libs)
-ULDFLAGS = $(LDFLAGS)
+ULDFLAGS = $(LDFLAGS) -lm
 ifeq (,$(findstring NO_GSSAPI,$(COMPAT)))
 ifeq (,$(findstring STATIC_GSSAPI,$(COMPAT)))
-XLDFLAGS+= -ldl
-ULDFLAGS+= -ldl
+XLDFLAGS+= ${DL_LIBS}
+ULDFLAGS+= ${DL_LIBS}
 else
 CFLAGS+= -DNO_LIBDL $(shell $(KRB5CONFIG) --cflags gssapi)
 XLDFLAGS+= $(shell $(KRB5CONFIG) --libs gssapi)
@@ -121,7 +121,7 @@ endif
 INSTALL=install
 INSTALL_PROGRAM=$(INSTALL)
 INSTALL_DATA=$(INSTALL)
-prefix=/usr/local
+prefix=${PREFIX}
 exec_prefix=$(prefix)
 bindir=$(exec_prefix)/bin
 mandir=$(prefix)/man