--- src/libs/libpng-1.2.54/aclocal.m4.orig	2020-07-10 02:58:17.000000000 +1000
+++ src/libs/libpng-1.2.54/aclocal.m4	2020-08-21 16:19:47.810386000 +1000
@@ -1728,7 +1728,7 @@
     lt_cv_sys_max_cmd_len=8192;
     ;;
 
-  bitrig* | darwin* | dragonfly* | freebsd* | netbsd* | openbsd*)
+  bsdsunix* | bitrig* | darwin* | dragonfly* | freebsd* | netbsd* | openbsd*)
     # This has been around since 386BSD, at least.  Likely further.
     if test -x /sbin/sysctl; then
       lt_cv_sys_max_cmd_len=`/sbin/sysctl -n kern.argmax`
@@ -2714,6 +2714,19 @@
   esac
   ;;
 
+bsdsunix*)
+  objformat=elf
+  version_type=bsdsunix-$objformat
+  library_names_spec='$libname$release$shared_ext$versuffix $libname$release$shared_ext$major $libname$shared_ext'
+  soname_spec='$libname$release$shared_ext$major'
+  need_version=no
+  need_lib_prefix=no
+  esac
+  shlibpath_var=LD_LIBRARY_PATH
+  shlibpath_overrides_runpath=yes
+  hardcode_into_libs=yes
+  ;;
+
 haiku*)
   version_type=linux # correct to gnu/linux during the next big refactor
   need_lib_prefix=no
@@ -3502,13 +3515,13 @@
   lt_cv_deplibs_check_method=pass_all
   ;;
 
-freebsd* | dragonfly*)
+bsdsunix* | freebsd* | dragonfly*)
   if echo __ELF__ | $CC -E - | $GREP __ELF__ > /dev/null; then
     case $host_cpu in
     i*86 )
       # Not sure whether the presence of OpenBSD here was a mistake.
       # Let's accept both of them until this is cleared up.
-      lt_cv_deplibs_check_method='file_magic (FreeBSD|OpenBSD|DragonFly)/i[[3-9]]86 (compact )?demand paged shared library'
+      lt_cv_deplibs_check_method='file_magic (BSDSUniX|FreeBSD|OpenBSD|DragonFly)/i[[3-9]]86 (compact )?demand paged shared library'
       lt_cv_file_magic_cmd=/usr/bin/file
       lt_cv_file_magic_test_file=`echo /usr/lib/libc.so.*`
       ;;
@@ -4331,7 +4344,7 @@
 	    ;;
 	esac
 	;;
-      freebsd* | dragonfly*)
+      bsdsunix* | freebsd* | dragonfly*)
 	# FreeBSD uses GNU C++
 	;;
       hpux9* | hpux10* | hpux11*)
@@ -5664,7 +5677,7 @@
       ;;
 
     # FreeBSD 3 and greater uses gcc -shared to do shared libraries.
-    freebsd* | dragonfly*)
+    bsdsunix* | freebsd* | dragonfly*)
       _LT_TAGVAR(archive_cmds, $1)='$CC -shared $pic_flag -o $lib $libobjs $deplibs $compiler_flags'
       _LT_TAGVAR(hardcode_libdir_flag_spec, $1)='-R$libdir'
       _LT_TAGVAR(hardcode_direct, $1)=yes
@@ -6770,7 +6783,7 @@
         _LT_TAGVAR(archive_cmds_need_lc, $1)=no
         ;;
 
-      freebsd* | dragonfly*)
+      bsdsunix* | freebsd* | dragonfly*)
         # FreeBSD 3 and later use GNU C++ and GNU ld with standard ELF
         # conventions
         _LT_TAGVAR(ld_shlibs, $1)=yes