1 files changed, 73 insertions, 0 deletions
diff --git a/ext/Unicode/Normalize/t/split.t b/ext/Unicode/Normalize/t/split.t
new file mode 100644
index 0000000000..03b599e123
--- /dev/null
+++ b/ext/Unicode/Normalize/t/split.t
@@ -0,0 +1,73 @@
+
+BEGIN {
+    unless ("A" eq pack('U', 0x41)) {
+	print "1..0 # Unicode::Normalize " .
+	    "cannot stringify a Unicode code point\n";
+	exit 0;
+    }
+}
+
+BEGIN {
+    if ($ENV{PERL_CORE}) {
+        chdir('t') if -d 't';
+        @INC = $^O eq 'MacOS' ? qw(::lib) : qw(../lib);
+    }
+}
+
+#########################
+
+use Test;
+use strict;
+use warnings;
+BEGIN { plan tests => 14 };
+use Unicode::Normalize qw(:all);
+ok(1); # If we made it this far, we're ok.
+
+sub _pack_U   { Unicode::Normalize::pack_U(@_) }
+sub _unpack_U { Unicode::Normalize::unpack_U(@_) }
+
+#########################
+
+our $proc;    # before the last starter
+our $unproc;  # the last starter and after
+# If string has no starter, entire string is set to $unproc.
+
+# When you have $normalized string and $unnormalized string following,
+# a simple concatenation
+#   C<$concat = $normalized . normalize($form, $unnormalized)>
+# is wrong. Instead of it, like this:
+#
+#       ($processed, $unprocessed) = splitOnLastStarter($normalized);
+#       $concat = $processed . normalize($form, $unprocessed.$unnormalized);
+
+($proc, $unproc) = splitOnLastStarter("");
+ok($proc,   "");
+ok($unproc, "");
+
+($proc, $unproc) = splitOnLastStarter("A");
+ok($proc,   "");
+ok($unproc, "A");
+
+($proc, $unproc) = splitOnLastStarter(_pack_U(0x41, 0x300, 0x327, 0x42));
+ok($proc,   _pack_U(0x41, 0x300, 0x327));
+ok($unproc, "B");
+
+($proc, $unproc) = splitOnLastStarter(_pack_U(0x4E00, 0x41, 0x301));
+ok($proc,   _pack_U(0x4E00));
+ok($unproc, _pack_U(0x41, 0x301));
+
+($proc, $unproc) = splitOnLastStarter(_pack_U(0x302, 0x301, 0x300));
+ok($proc,   "");
+ok($unproc, _pack_U(0x302, 0x301, 0x300));
+
+our $ka_grave = _pack_U(0x41, 0, 0x42, 0x304B, 0x300);
+our $dakuten  = _pack_U(0x3099);
+our $ga_grave = _pack_U(0x41, 0, 0x42, 0x304C, 0x300);
+
+our ($p, $u) = splitOnLastStarter($ka_grave);
+our $concat = $p . NFC($u.$dakuten);
+
+ok(NFC($ka_grave.$dakuten) eq $ga_grave);
+ok(NFC($ka_grave).NFC($dakuten) ne $ga_grave);
+ok($concat eq $ga_grave);
+