allocate sufficient buffer sizes for 64-bit wide utf8 characters

permitted by change#5011 (from Gisle Aas)

p4raw-link: @5011 on //depot/perl: 3c77ea2bace63b1ad27d15a6366cb938bdd158cb

p4raw-id: //depot/perl@5136

1 files changed, 2 insertions, 0 deletions

diff --git a/utf8.h b/utf8.h
index 8f69fef91e..c37a9959ef 100644
--- a/utf8.h
+++ b/utf8.h
@@ -27,6 +27,8 @@ EXTCONST unsigned char PL_utf8skip[];
 
 END_EXTERN_C
 
+#define UTF8_MAXLEN 13 /* how wide can a single UTF8 encoded character become */
+
 /*#define IN_UTF8 (PL_curcop->op_private & HINT_UTF8)*/
 #define IN_BYTE (PL_curcop->op_private & HINT_BYTE)
 #define DO_UTF8(sv) (SvUTF8(sv) && !IN_BYTE)