Gentoo bug: https://bugs.gentoo.org/919484
Upstream PR: https://github.com/avahi/nss-mdns/pull/93
diff --git a/Makefile.am b/Makefile.am
index d5a83c1..6df75f3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -17,9 +17,6 @@
 EXTRA_DIST=bootstrap.sh README.md ACKNOWLEDGEMENTS.md NEWS.md LICENSE
 ACLOCAL_AMFLAGS=-I m4
 
-# src
-EXTRA_DIST += src/map-file
-
 AM_CFLAGS = \
 	-DMDNS_ALLOW_FILE=\"$(MDNS_ALLOW_FILE)\" \
 	-DAVAHI_SOCKET=\"$(AVAHI_SOCKET)\"
@@ -47,29 +44,53 @@ endif
 
 check_PROGRAMS = nss-test avahi-test
 
+src/libnss-mdns-la-map-file: $(srcdir)/src/map-file.in $(srcdir)/src/nss.h
+	$(COMPILE) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(libnss_mdns_la_CFLAGS) -E -x assembler-with-cpp -DVER_SYM_MAP_GEN -o $@ $<
+
+src/libnss-mdns-minimal-la-map-file: $(srcdir)/src/map-file.in $(srcdir)/src/nss.h
+	$(COMPILE) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(libnss_mdns_minimal_la_CFLAGS) -E -x assembler-with-cpp -DVER_SYM_MAP_GEN -o $@ $<
+
+src/libnss-mdns4-la-map-file: $(srcdir)/src/map-file.in $(srcdir)/src/nss.h
+	$(COMPILE) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(libnss_mdns4_la_CFLAGS) -E -x assembler-with-cpp -DVER_SYM_MAP_GEN -o $@ $<
+
+src/libnss-mdns4-minimal-la-map-file: $(srcdir)/src/map-file.in $(srcdir)/src/nss.h
+	$(COMPILE) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(libnss_mdns4_minimal_la_CFLAGS) -E -x assembler-with-cpp -DVER_SYM_MAP_GEN -o $@ $<
+
+src/libnss-mdns6-la-map-file: $(srcdir)/src/map-file.in $(srcdir)/src/nss.h
+	$(COMPILE) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(libnss_mdns6_la_CFLAGS) -E -x assembler-with-cpp -DVER_SYM_MAP_GEN -o $@ $<
+
+src/libnss-mdns6-minimal-la-map-file: $(srcdir)/src/map-file.in $(srcdir)/src/nss.h
+	$(COMPILE) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(libnss_mdns6_minimal_la_CFLAGS) -E -x assembler-with-cpp -DVER_SYM_MAP_GEN -o $@ $<
+
 libnss_mdns_la_SOURCES=src/util.c src/util.h src/avahi.c src/avahi.h src/nss.c src/nss.h
+EXTRA_libnss_mdns_la_DEPENDENCIES=src/libnss-mdns-la-map-file
 libnss_mdns_la_CFLAGS=$(AM_CFLAGS)
-libnss_mdns_la_LDFLAGS=$(AM_LDFLAGS) -shrext .so.2 -Wl,-version-script=$(srcdir)/src/map-file
+libnss_mdns_la_LDFLAGS=$(AM_LDFLAGS) -shrext .so.2 -Wl,-version-script=src/libnss-mdns-la-map-file
 
 libnss_mdns_minimal_la_SOURCES=$(libnss_mdns_la_SOURCES)
+EXTRA_libnss_mdns_minimal_la_DEPENDENCIES=src/libnss-mdns-minimal-la-map-file
 libnss_mdns_minimal_la_CFLAGS=$(libnss_mdns_la_CFLAGS) -DMDNS_MINIMAL
-libnss_mdns_minimal_la_LDFLAGS=$(libnss_mdns_la_LDFLAGS)
+libnss_mdns_minimal_la_LDFLAGS=$(AM_LDFLAGS) -shrext .so.2 -Wl,-version-script=src/libnss-mdns-minimal-la-map-file
 
 libnss_mdns4_la_SOURCES=$(libnss_mdns_la_SOURCES)
+EXTRA_libnss_mdns4_la_DEPENDENCIES=src/libnss-mdns4-la-map-file
 libnss_mdns4_la_CFLAGS=$(libnss_mdns_la_CFLAGS) -DNSS_IPV4_ONLY=1
-libnss_mdns4_la_LDFLAGS=$(libnss_mdns_la_LDFLAGS)
+libnss_mdns4_la_LDFLAGS=$(AM_LDFLAGS) -shrext .so.2 -Wl,-version-script=src/libnss-mdns4-la-map-file
 
 libnss_mdns4_minimal_la_SOURCES=$(libnss_mdns_la_SOURCES)
+EXTRA_libnss_mdns4_minimal_la_DEPENDENCIES=src/libnss-mdns4-minimal-la-map-file
 libnss_mdns4_minimal_la_CFLAGS=$(libnss_mdns_la_CFLAGS) -DNSS_IPV4_ONLY=1 -DMDNS_MINIMAL
-libnss_mdns4_minimal_la_LDFLAGS=$(libnss_mdns_la_LDFLAGS)
+libnss_mdns4_minimal_la_LDFLAGS=$(AM_LDFLAGS) -shrext .so.2 -Wl,-version-script=src/libnss-mdns4-minimal-la-map-file
 
 libnss_mdns6_la_SOURCES=$(libnss_mdns_la_SOURCES)
+EXTRA_libnss_mdns6_la_DEPENDENCIES=src/libnss-mdns6-la-map-file
 libnss_mdns6_la_CFLAGS=$(libnss_mdns_la_CFLAGS) -DNSS_IPV6_ONLY=1
-libnss_mdns6_la_LDFLAGS=$(libnss_mdns_la_LDFLAGS)
+libnss_mdns6_la_LDFLAGS=$(AM_LDFLAGS) -shrext .so.2 -Wl,-version-script=src/libnss-mdns6-la-map-file
 
 libnss_mdns6_minimal_la_SOURCES=$(libnss_mdns_la_SOURCES)
+EXTRA_libnss_mdns6_minimal_la_DEPENDENCIES=src/libnss-mdns6-minimal-la-map-file
 libnss_mdns6_minimal_la_CFLAGS=$(libnss_mdns_la_CFLAGS) -DNSS_IPV6_ONLY=1 -DMDNS_MINIMAL
-libnss_mdns6_minimal_la_LDFLAGS=$(libnss_mdns_la_LDFLAGS)
+libnss_mdns6_minimal_la_LDFLAGS=$(AM_LDFLAGS) -shrext .so.2 -Wl,-version-script=src/libnss-mdns6-minimal-la-map-file
 
 nss_mdns_la_SOURCES=$(libnss_mdns_la_SOURCES) src/bsdnss.c
 nss_mdns_la_CFLAGS=$(AM_CFLAGS)
diff --git a/src/map-file b/src/map-file
deleted file mode 100644
index 69e7987..0000000
--- a/src/map-file
+++ /dev/null
@@ -1,41 +0,0 @@
-NSSMDNS_0 {
-global:
-
-_nss_mdns_gethostbyaddr_r;
-_nss_mdns4_gethostbyaddr_r;
-_nss_mdns6_gethostbyaddr_r;
-_nss_mdns_minimal_gethostbyaddr_r;
-_nss_mdns4_minimal_gethostbyaddr_r;
-_nss_mdns6_minimal_gethostbyaddr_r;
-
-_nss_mdns_gethostbyname_r;
-_nss_mdns4_gethostbyname_r;
-_nss_mdns6_gethostbyname_r;
-_nss_mdns_minimal_gethostbyname_r;
-_nss_mdns4_minimal_gethostbyname_r;
-_nss_mdns6_minimal_gethostbyname_r;
-
-_nss_mdns_gethostbyname2_r;
-_nss_mdns4_gethostbyname2_r;
-_nss_mdns6_gethostbyname2_r;
-_nss_mdns_minimal_gethostbyname2_r;
-_nss_mdns4_minimal_gethostbyname2_r;
-_nss_mdns6_minimal_gethostbyname2_r;
-
-_nss_mdns_gethostbyname3_r;
-_nss_mdns4_gethostbyname3_r;
-_nss_mdns6_gethostbyname3_r;
-_nss_mdns_minimal_gethostbyname3_r;
-_nss_mdns4_minimal_gethostbyname3_r;
-_nss_mdns6_minimal_gethostbyname3_r;
-
-_nss_mdns_gethostbyname4_r;
-_nss_mdns4_gethostbyname4_r;
-_nss_mdns6_gethostbyname4_r;
-_nss_mdns_minimal_gethostbyname4_r;
-_nss_mdns4_minimal_gethostbyname4_r;
-_nss_mdns6_minimal_gethostbyname4_r;
-
-local:
-*;
-};
diff --git a/src/map-file.in b/src/map-file.in
new file mode 100644
index 0000000..caecf41
--- /dev/null
+++ b/src/map-file.in
@@ -0,0 +1,14 @@
+NSSMDNS_0 {
+global:
+
+#include "nss.h"
+
+_nss_mdns_gethostbyaddr_r;
+_nss_mdns_gethostbyname2_r;
+_nss_mdns_gethostbyname3_r;
+_nss_mdns_gethostbyname4_r;
+_nss_mdns_gethostbyname_r;
+
+local:
+*;
+};
diff --git a/src/nss.h b/src/nss.h
index dd8dbff..d63f51c 100644
--- a/src/nss.h
+++ b/src/nss.h
@@ -33,6 +33,7 @@
 #define _nss_mdns_gethostbyaddr_r _nss_mdns_minimal_gethostbyaddr_r
 #endif
 
+#ifndef VER_SYM_MAP_GEN
 // Define prototypes for nss function we're going to export (fixes GCC warnings)
 #ifndef __FreeBSD__
 enum nss_status _nss_mdns_gethostbyname4_r(const char*, struct gaih_addrtuple**,
@@ -50,3 +51,4 @@ enum nss_status _nss_mdns_gethostbyaddr_r(const void*, int, int,
                                           int*);
 
 #endif
+#endif