Tweak sv_pos_b2u_flags check in pp_index

There's no need to run sv_pos_b2u_flags if the retval is one as
one byte can only be one character, therefore change the test to
"> 1". This makes index on unicode strings that match at 1 slightly
faster.

1 files changed, 5 insertions, 1 deletions

diff --git a/t/op/index.t b/t/op/index.t
index fd5a98fc48..29a477146e 100644
--- a/t/op/index.t
+++ b/t/op/index.t
@@ -8,7 +8,7 @@ BEGIN {
 }
 
 use strict;
-plan( tests => 121 );
+plan( tests => 122 );
 
 run_tests() unless caller;
 
@@ -253,3 +253,7 @@ is index('the main road', __PACKAGE__), 4,
     '[perl #119169] __PACKAGE__ as 2nd argument';
 
 } # end of sub run_tests
+
+utf8::upgrade my $substr = "\x{a3}a";
+
+is index($substr, 'a'), 1, 'index reply reflects characters not octets';