foldEQ_utf8_flags: Add no-mixing ASCII option

If this option is set, any match that has a non-ASCII character that has
an ASCII character in its fold will not match that fold.

diff --git a/utf8.c b/utf8.c
index 4399fca..b5d8531 100644 (file)
--- a/utf8.c
+++ b/utf8.c
@@ -3033,6 +3033,13 @@ instead of upper/lowercasing both the characters, see
 http://www.unicode.org/unicode/reports/tr21/ (Case Mappings).
 
 =cut */
+
+/* A flags parameter has been added which may change, and hence isn't
+ * externally documented.  Currently it is:
+ *  0 for as-documented above
+ *  FOLDEQ_UTF8_NOMIX_ASCII meaning that if a non-ASCII character folds to an
+                           ASCII one, to not match
+ */
 I32
 Perl_foldEQ_utf8_flags(pTHX_ const char *s1, char **pe1, register UV l1, bool u1, const char *s2, char **pe2, register UV l2, bool u2, U32 flags)
 {
@@ -3100,7 +3107,16 @@ Perl_foldEQ_utf8_flags(pTHX_ const char *s1, char **pe1, register UV l1, bool u1
         /* If at the beginning of a new character in s1, get its fold to use
          * and the length of the fold */
         if (n1 == 0) {
-            if (u1) {
+           if (isASCII(*p1)) {
+
+               /* But if not to mix non- with ASCII, fail */
+               if ((flags & FOLDEQ_UTF8_NOMIX_ASCII) && ! isASCII(*p2)) {
+                   return 0;
+               }
+               n1 = 1;
+               *foldbuf1 = toLOWER(*p1);   /* ASCII range fold is lowercase */
+           }
+           else if (u1) {
                 to_utf8_fold(p1, foldbuf1, &n1);
             }
             else {  /* Not utf8, convert to it first and then get fold */
@@ -3111,7 +3127,14 @@ Perl_foldEQ_utf8_flags(pTHX_ const char *s1, char **pe1, register UV l1, bool u1
         }
 
         if (n2 == 0) {    /* Same for s2 */
-            if (u2) {
+           if (isASCII(*p2)) {
+               if (flags && ! isASCII(*p1)) {
+                   return 0;
+               }
+               n2 = 1;
+               *foldbuf2 = toLOWER(*p2);
+           }
+           else if (u2) {
                 to_utf8_fold(p2, foldbuf2, &n2);
             }
             else {

diff --git a/utf8.h b/utf8.h
index 2386eb6..e0dee68 100644 (file)
--- a/utf8.h
+++ b/utf8.h
@@ -22,6 +22,8 @@
 
 #define foldEQ_utf8(s1, pe1, l1, u1, s2, pe2, l2, u2) \
                    foldEQ_utf8_flags(s1, pe1, l1, u1, s2, pe2, l2, u2, 0)
+#define FOLDEQ_UTF8_NOMIX_ASCII (1 << 0)
+
 /*
 =for apidoc ibcmp_utf8