RTI add zlib.pc to devel/zlib

[Richard PALO <richard.palo%free.fr@localhost>]

In working on updating cups to 1.7 and adding cups-filters to pkgsrc, I 
came across (on solaris) that the pkgsrc zlib doesn't have a zlib.pc 
whereas on my illumos-based distribution, it surprisingly does.

Not to mention that zlib doesn't create ZLIB_CFLAGS, ZLIB_LIBS,...

It seems appropriate to facilitate getting at least pkg-config to work.

Attached is a git diff for comments/approval.

diff --git a/devel/zlib/Makefile b/devel/zlib/Makefile
index d2c7ab7..7d3addf 100644
--- a/devel/zlib/Makefile
+++ b/devel/zlib/Makefile
@@ -1,6 +1,7 @@
 # $NetBSD: Makefile,v 1.47 2013/05/27 16:22:10 adam Exp $
 
 DISTNAME=      zlib-1.2.8
+PKGREVISION=   1
 CATEGORIES=    devel
 MASTER_SITES=  ${MASTER_SITE_SOURCEFORGE:=libpng/} \
                http://zlib.net/
@@ -15,18 +16,30 @@ PKG_INSTALLATION_TYPES=     overwrite pkgviews
 
 USE_LIBTOOL=           yes
 
+PKGCONFIG_OVERRIDE+=   zlib.pc.in
+
 CFLAGS+=               ${CPPFLAGS}
 LDFLAGS.Cygwin=                -no-undefined
 
-INSTALLATION_DIRS=     include lib ${PKGMANDIR}/man3
+SED_TRANSFORMS+=    -e "s,@prefix@,${PREFIX},g"
+SED_TRANSFORMS+=    -e "s,@exec_prefix@,${PREFIX},g"
+SED_TRANSFORMS+=    -e "s,@PACKAGE_VERSION@,${PKGVERSION_NOREV},g"
+SED_TRANSFORMS+=    -e "s,@includedir@,${PREFIX}/include,g"
+SED_TRANSFORMS+=    -e "s,@libdir@,${PREFIX}/lib,g"
+
+INSTALLATION_DIRS=     include lib lib/pkgconfig ${PKGMANDIR}/man3
 
 do-extract:
        ${CP} -r ${FILESDIR} ${WRKSRC}
 
+post-build:
+       cd ${WRKSRC} && ${SED} ${SED_TRANSFORMS} zlib.pc.in >zlib.pc
+
 do-install:
        ${LIBTOOL} --mode=install ${INSTALL_LIB} ${WRKSRC}/libz.la 
${DESTDIR}${PREFIX}/lib
        ${INSTALL_MAN} ${WRKSRC}/zlib.3 ${DESTDIR}${PREFIX}/${PKGMANDIR}/man3
        ${INSTALL_DATA} ${WRKSRC}/zconf.h ${DESTDIR}${PREFIX}/include
        ${INSTALL_DATA} ${WRKSRC}/zlib.h ${DESTDIR}${PREFIX}/include
+       ${INSTALL_DATA} ${WRKSRC}/zlib.pc ${DESTDIR}${PREFIX}/lib/pkgconfig
 
 .include "../../mk/bsd.pkg.mk"
diff --git a/devel/zlib/PLIST b/devel/zlib/PLIST
index 7008f62..5ef561a 100644
--- a/devel/zlib/PLIST
+++ b/devel/zlib/PLIST
@@ -2,4 +2,5 @@
 include/zconf.h
 include/zlib.h
 lib/libz.la
+lib/pkgconfig/zlib.pc
 man/man3/zlib.3
diff --git a/devel/zlib/files/zlib.pc.in b/devel/zlib/files/zlib.pc.in
new file mode 100644
index 0000000..ee2ccc2
--- /dev/null
+++ b/devel/zlib/files/zlib.pc.in
@@ -0,0 +1,10 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: zlib
+Description: zlib compression library
+Version: @PACKAGE_VERSION@
+Cflags: -I${includedir}
+Libs: -L${libdir} -lz