tests: add a check to prevent bashisms from creeping into code

Makefile

@@ -75,6 +75,9 @@ check:
 	echo 'To suppress tests in debuild, export DEB_BUILD_OPTIONS=nocheck'
 	echo ''
 	echo 'FIXME: this should kill stray wine processes before and after, but some leak through, you might need to kill them.'
+	# Check for shellscript issues first:
+	echo "Running checkbashisms:"
+	sh ./tests/prevent-bashims || exit 1
 	# Check all script dependencies before starting tests:
 	echo "Checking dependencies.."
 	sh ./src/linkcheck.sh check-deps || exit 1
@@ -103,6 +106,9 @@ test:
 	echo 'To suppress tests in debuild, export DEB_BUILD_OPTIONS=nocheck'
 	echo ''
 	echo 'FIXME: this should kill stray wine processes before and after, but some leak through, you might need to kill them.'
+	# Check for shellscript issues first:
+	echo "Running checkbashisms:"
+	sh ./tests/prevent-bashims || exit 1
 	# Check all script dependencies before starting tests:
 	echo "Checking dependencies.."
 	sh ./src/linkcheck.sh check-deps || exit 1

tests/prevent-bashims

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+set -x
+set -e
+
+# Copyright 2016 Austin English
+# LPGL 2.1+
+
+# Wrapper around checkbashisms
+# May also add other checks in future, like shellcheck
+
+if [ ! command -v checkbashisms > /dev/null 2>&1 ] ; then
+    echo "checkbashisms must be installed!"
+fi
+
+for shellscript in \
+    $(find . -type f -not -path "./.git/*" -exec file {} \; | grep -e 'POSIX shell script' | cut -d : -f1)
+do
+    echo "Checking ${shellscript}:"
+    checkbashisms ${shellscript} || exit 1
+done