+CHECK_I18N_RECODE([from ISO-8859-1 to UTF-8 with overflow],
+ [ISO-8859-1], [UTF-8],
+ [Tsch\374\337!], [Tsch\303\274\303\237!])
+\f
+AT_BANNER([i18n concatenation])
+
+# CHECK_I18N_CONCAT([HEAD], [TAIL], [ENCODING], [MAX-LEN], [ANSWER])
+#
+# Concatenates HEAD and TAIL, omitting as many characters from HEAD as needed
+# to make the result come out to no more than MAX-LEN bytes if it was expressed
+# in ENCODING, and checks that the answer matches ANSWER. HEAD, TAIL, and
+# ANSWER are all in UTF-8. The "printf" program is applied to HEAD, TAIL, and
+# ANSWER to allow for backslash-escapes. (Hex escapes are not portable; use
+# octal escapes instead.)
+m4_define([CHECK_I18N_CONCAT],
+ [AT_SETUP([m4_if([$2], [], [truncate "$1" to $4 bytes in $3],
+ [truncate "$1" + "$2" to $4 bytes in $3])])
+ AT_KEYWORDS([i18n])
+
+ dnl Skip the test if this host doesn't know the encoding.
+ AT_CHECK([supports_encodings '$3'])
+ AT_CHECK_UNQUOTED(
+ [i18n-test concat "`printf '$1'`" "`printf '$2'`" '$3' '$4'], [0],
+ [`printf '$5'`
+])
+ AT_CLEANUP])
+
+CHECK_I18N_CONCAT([abc], [], [UTF-8], [6], [abc])
+CHECK_I18N_CONCAT([], [xyz], [UTF-8], [6], [xyz])
+CHECK_I18N_CONCAT([], [], [UTF-8], [6], [])
+CHECK_I18N_CONCAT([abcdefghij], [], [UTF-8], [6], [abcdef])
+CHECK_I18N_CONCAT([], [tuvwxyz], [UTF-8], [6], [tuvwxyz])
+
+CHECK_I18N_CONCAT([abc], [xyz], [UTF-8], [6], [abcxyz])
+CHECK_I18N_CONCAT([abcd], [xyz], [UTF-8], [6], [abcxyz])
+CHECK_I18N_CONCAT([abc], [uvwxyz], [UTF-8], [6], [uvwxyz])
+
+# x in a box ( x⃞ ) is U+0078, U+20DE, 4 bytes in UTF-8, and one grapheme
+# cluster.
+CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [0], [y])
+CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [1], [y])
+CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [2], [y])
+CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [3], [y])
+CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [4], [y])
+CHECK_I18N_CONCAT([x\342\203\236], [y], [UTF-8], [5], [x\342\203\236y])