From e2c707d8b12fcf8deed952de8b1a181df6652cca Mon Sep 17 00:00:00 2001
From: "Bob W. Hogg" <rwhogg@linux.com>
Date: Fri, 21 Apr 2017 09:32:30 -0700
Subject: [PATCH] Stdenv: Add ENV.libxml2 and ENV.x11 for Linux

Add ENV.libxml2 primarily for the use of test do blocks.
Add a dummy ENV.x11 function.

See Linuxbrew/brew#356 and Linuxbrew/brew#382
---
 Library/Homebrew/extend/ENV/std.rb                 | 2 ++
 Library/Homebrew/extend/os/extend/ENV/std.rb       | 6 +++++-
 Library/Homebrew/extend/os/linux/extend/ENV/std.rb | 7 +++++++
 3 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 Library/Homebrew/extend/os/linux/extend/ENV/std.rb

diff --git a/Library/Homebrew/extend/ENV/std.rb b/Library/Homebrew/extend/ENV/std.rb
index c4cc0985fb..91189f53ab 100644
--- a/Library/Homebrew/extend/ENV/std.rb
+++ b/Library/Homebrew/extend/ENV/std.rb
@@ -210,6 +210,8 @@ module Stdenv
   end
   alias generic_set_cpu_flags set_cpu_flags
 
+  def x11; end
+
   # @private
   def effective_arch
     if ARGV.build_bottle?
diff --git a/Library/Homebrew/extend/os/extend/ENV/std.rb b/Library/Homebrew/extend/os/extend/ENV/std.rb
index 8e6b13a61e..18ede5b9ed 100644
--- a/Library/Homebrew/extend/os/extend/ENV/std.rb
+++ b/Library/Homebrew/extend/os/extend/ENV/std.rb
@@ -1,2 +1,6 @@
 require "extend/ENV/std"
-require "extend/os/mac/extend/ENV/std" if OS.mac?
+if OS.mac?
+  require "extend/os/mac/extend/ENV/std"
+elsif OS.linux?
+  require "extend/os/linux/extend/ENV/std"
+end
diff --git a/Library/Homebrew/extend/os/linux/extend/ENV/std.rb b/Library/Homebrew/extend/os/linux/extend/ENV/std.rb
new file mode 100644
index 0000000000..ed19d2495c
--- /dev/null
+++ b/Library/Homebrew/extend/os/linux/extend/ENV/std.rb
@@ -0,0 +1,7 @@
+module Stdenv
+  def libxml2
+    append "CPPFLAGS", "-I#{Formula["libxml2"].include/"libxml2"}"
+  rescue FormulaUnavailableError
+    nil
+  end
+end