From b10224be6284a522b384f2319d00432629c1e7dc Mon Sep 17 00:00:00 2001
From: Jan Kloetzke <jan.kloetzke@freenet.de>
Date: Tue, 1 Nov 2011 19:17:01 +0100
Subject: [PATCH] Fix rebar_utils:expand_env_variable/3

The function may fail with a badarg exception because the first regex
returns an iolist() which is allowed to be a improper list. In this case
'++' cannot append to the iolist. The correct way to append something to
an iolist() is

  [iolist(), "tail"]

because iolist's are allowed to be arbitrarily deep lists.
---
 src/rebar_utils.erl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/rebar_utils.erl b/src/rebar_utils.erl
index a32adfd..ce84a57 100644
--- a/src/rebar_utils.erl
+++ b/src/rebar_utils.erl
@@ -196,7 +196,7 @@ expand_env_variable(InStr, VarName, RawVarValue) ->
             %% Given variable "FOO": match $FOO\s | $FOOeol | ${FOO}
             RegEx = io_lib:format("\\\$(~s(\\s|$)|{~s})", [VarName, VarName]),
             ReOpts = [global, {return, list}],
-            re:replace(InStr, RegEx, VarValue ++ "\\2", ReOpts)
+            re:replace(InStr, RegEx, [VarValue, "\\2"], ReOpts)
     end.