homebrew_p7zip_nsis_decompiler.patch

diff --git a/Formula/p7zip.rb b/Formula/p7zip.rb
index a102437388..0e97ac74ee 100644
--- a/Formula/p7zip.rb
+++ b/Formula/p7zip.rb
@@ -12,11 +12,18 @@ class P7zip < Formula
     sha256 "78981de13a763ab595e073360e2848ca0ad65d9a13b7f7728e0c255945cdd00e" => :mavericks
   end
 
+  option "with-nsis-decompiler", "Build with NSIS decompiler support"
+
   def install
+    if build.with? "nsis-decompiler"
+      flags = "$(ALLFLAGS) -DNSIS_SCRIPT"
+    else
+      flags = "$(ALLFLAGS)"
+    end
     mv "makefile.macosx_llvm_64bits", "makefile.machine"
     system "make", "all3",
-                   "CC=#{ENV.cc} $(ALLFLAGS)",
-                   "CXX=#{ENV.cxx} $(ALLFLAGS)"
+                   "CC=#{ENV.cc} #{flags}",
+                   "CXX=#{ENV.cxx} #{flags}"
     system "make", "DEST_HOME=#{prefix}",
                    "DEST_MAN=#{man}",
                    "install"