API test for find_rundefsv()

2 files changed, 34 insertions, 0 deletions

diff --git a/ext/XS-APItest/APItest.xs b/ext/XS-APItest/APItest.xs
index 0b3a6cba3d..d3d7274fca 100644
--- a/ext/XS-APItest/APItest.xs
+++ b/ext/XS-APItest/APItest.xs
@@ -2861,6 +2861,20 @@ CODE:
 OUTPUT:
     RETVAL
 
+STRLEN
+underscore_length()
+PROTOTYPE:
+PREINIT:
+    SV *u;
+    U8 *pv;
+    STRLEN bytelen;
+CODE:
+    u = find_rundefsv();
+    pv = (U8*)SvPV(u, bytelen);
+    RETVAL = SvUTF8(u) ? utf8_length(pv, pv+bytelen) : bytelen;
+OUTPUT:
+    RETVAL
+
 MODULE = XS::APItest		PACKAGE = XS::APItest::Magic
 
 PROTOTYPES: DISABLE
diff --git a/ext/XS-APItest/t/underscore_length.t b/ext/XS-APItest/t/underscore_length.t
new file mode 100644
index 0000000000..7ca6906322
--- /dev/null
+++ b/ext/XS-APItest/t/underscore_length.t
@@ -0,0 +1,20 @@
+use warnings;
+use strict;
+
+use Test::More tests => 4;
+
+use XS::APItest qw(underscore_length);
+
+$_ = "foo";
+is underscore_length(), 3;
+
+$_ = "snowman \x{2603}";
+is underscore_length(), 9;
+
+my $_ = "xyzzy";
+is underscore_length(), 5;
+
+$_ = "pile of poo \x{1f4a9}";
+is underscore_length(), 13;
+
+1;