apply bsd-compatibility patch to Onigmo (k-takata/Onigmo#55)

Onigmo-bsd-compat.patch

@@ -0,0 +1,26 @@
+diff --git Makefile.am Makefile.am
+index 07cf35f..1acf663 100644
+--- Makefile.am
++++ Makefile.am
+@@ -65,7 +65,7 @@ do_subst = sed                                          \
+       -e 's,[@]includedir[@],$(includedir),g'
+
+ oniguruma.pc: $(srcdir)/oniguruma.pc.in Makefile
+-	$(do_subst) < $(<) > $(@)
++	$(do_subst) < $(srcdir)/oniguruma.pc.in > $(@)
+
+ pkgconfigdir   = $(libdir)/pkgconfig
+ pkgconfig_DATA = oniguruma.pc
+diff --git Makefile.in Makefile.in
+index 5849df9..d4e4c0e 100644
+--- Makefile.in
++++ Makefile.in
+@@ -1428,7 +1428,7 @@ uninstall-am: uninstall-binSCRIPTS uninstall-includeHEADERS \
+ onig-config: onig-config.in
+
+ oniguruma.pc: $(srcdir)/oniguruma.pc.in Makefile
+-	$(do_subst) < $(<) > $(@)
++	$(do_subst) < $(srcdir)/oniguruma.pc.in > $(@)
+
+ dll:
+ 	$(CXX) -shared -Wl,--output-def,libonig.def -o libonig.dll *.o \

mrbgem.rake

@@ -31,6 +31,11 @@ MRuby::Gem::Specification.new('mruby-onig-regexp') do |spec|
         _pp 'extracting', "Onigmo-#{version}"
         `gzip -dc "#{dir}/Onigmo-#{version}.tar.gz" | tar xf -`
       end
+      unless ENV['OS'] == 'Windows_NT'
+        Dir.chdir(oniguruma_dir) do
+          `patch -p0 < #{dir}/Onigmo-bsd-compat.patch`
+        end
+      end
     end
 
     def run_command(env, command)