1 files changed, 100 insertions, 0 deletions
diff --git a/t/var-undef-append.sh b/t/var-undef-append.sh
new file mode 100644
index 000000000..de4c926ac
--- /dev/null
+++ b/t/var-undef-append.sh
@@ -0,0 +1,100 @@
+#! /bin/sh
+# Copyright (C) 2012-2015 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Automake should allow us top append to undefined variables, for
+# consistency with GNU make.  For the same reason, if we override
+# a variable definition from the command line, any '+=' appending
+# to it should get overridden as well.
+# See also "spy" test 'spy-var-append.sh'.
+
+. test-init.sh
+
+cat >> configure.ac << 'END'
+AM_CONDITIONAL([COND_NO], [false])
+AM_CONDITIONAL([COND_YES], [:])
+AM_CONDITIONAL([COND_YES2], [:])
+AC_OUTPUT
+END
+
+cat > Makefile.am << 'END'
+var0 += foo0
+
+if COND_NO
+var00 += foo00
+endif
+
+if COND_YES
+if COND_YES2
+var000 += foo000
+endif
+endif
+
+if COND_NO
+var1 = oops
+endif
+var1 += bar
+if COND_YES
+var1 += baz
+endif
+if COND_NO
+var1 += oops
+endif
+
+if COND_YES
+var2 = a
+endif
+var2 += b
+
+if COND_YES
+var3 := c
+endif
+var3 += d
+
+var4 = cuckoo
+var4 += nightingale
+
+.PHONY: test1 test2
+test1:
+	test x'$(var0)' = x'foo0'
+	test x'$(var00)' = x''
+	test x'$(var000)' = x'foo000'
+	test x'$(var1)' = x'bar baz'
+	test x'$(var2)' = x'a b'
+	test x'$(var3)' = x'c d'
+        test x'$(var4)' = x'cuckoo nightingale'
+test2:
+	test x'$(var0)' = x
+	test x'$(var1)' = x'one'
+	test x'$(var2)' = x'two'
+	test x'$(var3)' = x'three'
+	test x'$(var4)' = x''
+END
+
+$ACLOCAL
+$AUTOMAKE
+$AUTOCONF
+
+./configure
+
+checkit ()
+{
+  run_make -E -- "$@" && test ! -s stderr
+}
+
+checkit test1
+checkit test2 var0= var1=one var2=two var3=three var4=
+
+: