From dff2462c63f8046561043e6757c57b3a5c41c888 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@drexel.edu>
Date: Thu, 1 Dec 2011 07:51:24 -0500
Subject: [PATCH] Add check for Bash >= 3.1 (required for += array assignment).

Browsing through the changelog
  http://git.savannah.gnu.org/cgit/bash.git/tree/CWRU/changelog
the change that added += was
  2004/11/05
  general.c
  - change `assignment()' to accept `+=' assignment operator
Looking through the released tarballs
  ftp://ftp.gnu.org/gnu/bash/
this change made it in between release 3.0.16 and 3.1.
---
 dotfiles.sh | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/dotfiles.sh b/dotfiles.sh
index d1305dd..b660596 100755
--- a/dotfiles.sh
+++ b/dotfiles.sh
@@ -24,12 +24,21 @@ TOUCH=$(which touch)
 WGET=$(which wget)
 
 #####
-# Utility functions
+# Compatibility checks
 
 BASH="${BASH_VERSION%.*}"
 BASH_MAJOR="${BASH%.*}"
 BASH_MINOR="${BASH#*.}"
 
+if [ "${BASH_MAJOR}" -eq 3 ] && [ "${BASH_MINOR}" -eq 0 ]; then
+	echo "ERROR: ${0} requires Bash version >= 3.1" >&2
+	echo "you're running ${BASH}, which doesn't support += array assignment" >&2
+	exit 1
+fi
+
+#####
+# Utility functions
+
 # usage: nonempty_option LOC NAME VALUE
 function nonempty_option()
 {
-- 
2.26.2