PATCH: [perl #101710] Regression with /i, latin1 chars.

The root cause of this bug is that it was assuming that a string was in
utf8 when it wasn't, and so was thinking that a byte was a starter byte
that wasn't, so was skipping ahead based on that starter byte.

1 files changed, 8 insertions, 1 deletions

diff --git a/t/re/pat.t b/t/re/pat.t
index ed87f07701..54d44ac046 100644
--- a/t/re/pat.t
+++ b/t/re/pat.t
@@ -21,7 +21,7 @@ BEGIN {
     require './test.pl';
 }
 
-plan tests => 463;  # Update this when adding/deleting tests.
+plan tests => 464;  # Update this when adding/deleting tests.
 
 run_tests() unless caller;
 
@@ -1208,6 +1208,13 @@ EOP
                         sprintf("'U+%04X not legal IDFirst'", ord($char)));
         }
     }
+
+    { # [perl #101710]
+        my $pat = "b";
+        utf8::upgrade($pat);
+        like("\xffb", qr/$pat/i, "/i: utf8 pattern, non-utf8 string, latin1-char preceding matching char in string");
+    }
+
 } # End of sub run_tests
 
 1;