From 346591e41aba9b0af60165fb5207471ab2a4473b Mon Sep 17 00:00:00 2001
From: Keegan McAllister <kmcallister@mozilla.com>
Date: Fri, 11 Oct 2013 16:26:05 -0700
Subject: [PATCH] configure: Prevent in-tree builds

Fixes #251.
---
 configure | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/configure b/configure
index 9cd474397f7..af25ebc9adc 100755
--- a/configure
+++ b/configure
@@ -258,6 +258,16 @@ cpu_type() {
     esac
 }
 
+if [ -f configure -a -f Makefile.in ]; then
+    msg "You seem to be running configure within the source tree root."
+    msg "This is not supported.  Instead, make a build directory:"
+    msg ""
+    msg "    mkdir -p build && cd build && ../configure"
+    msg ""
+    msg "See README.md for more information."
+    exit 1
+fi
+
 msg "looking for configure programs"
 need_cmd cmp
 need_cmd mkdir