More Unicode folding tweaks, avoid potential false matches.

p4raw-id: //depot/perl@13967

diff --git a/regexec.c b/regexec.c
index cb56bab..7f1298f 100644 (file)
--- a/regexec.c
+++ b/regexec.c
@@ -966,7 +966,11 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, char *sta
                e = s;                  /* Due to minlen logic of intuit() */
 
            if (do_utf8) {
-               STRLEN len;
+               UV c, f;
+               U8 tmpbuf [UTF8_MAXLEN+1];
+               U8 foldbuf[UTF8_MAXLEN_FOLD+1];
+               STRLEN len, foldlen;
+
                /* The ibcmp_utf8() uses to_uni_fold() which is more
                 * correct folding for Unicode than using lowercase.
                 * However, it doesn't work quite fully since the folding
@@ -977,10 +981,15 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, char *sta
                 * only one-to-one matching is required. --jhi */
                if (c1 == c2) {
                    while (s <= e) {
-                       if ( utf8_to_uvchr((U8*)s, &len) == c1
-                            && (ln == len ||
-                                !ibcmp_utf8(s, do_utf8, (I32)(strend - s),
-                                            m, UTF, (I32)ln))
+                       c = utf8_to_uvchr((U8*)s, &len);
+                       uvchr_to_utf8(tmpbuf, c);
+                       to_utf8_fold(tmpbuf, foldbuf, &foldlen);
+                       f = utf8_to_uvchr(foldbuf, 0);
+                       
+                       if ( (c == c1 && ln == len) ||
+                            (f == c1 && ln == foldlen)
+                            || !ibcmp_utf8(s, do_utf8, (I32)(strend - s),
+                                           m, UTF, (I32)ln)
                             && (norun || regtry(prog, s)) )
                            goto got_it;
                        s += len;
@@ -988,12 +997,7 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, char *sta
                }
                else {
                    while (s <= e) {
-                       U8 tmpbuf [UTF8_MAXLEN+1];
-                       U8 foldbuf[UTF8_MAXLEN_FOLD+1];
-                       STRLEN foldlen;
-                       UV c = utf8_to_uvchr((U8*)s, &len);
-                       UV f;
-
+                       c = utf8_to_uvchr((U8*)s, &len);
                        uvchr_to_utf8(tmpbuf, c);
                        to_utf8_fold(tmpbuf, foldbuf, &foldlen);
                        f = utf8_to_uvchr(foldbuf, 0);
@@ -1001,10 +1005,10 @@ S_find_byclass(pTHX_ regexp * prog, regnode *c, char *s, char *strend, char *sta
                        if (c == (UV)UNICODE_GREEK_CAPITAL_LETTER_SIGMA ||
                            c == (UV)UNICODE_GREEK_SMALL_LETTER_FINAL_SIGMA)
                            c = (UV)UNICODE_GREEK_SMALL_LETTER_SIGMA;
-                       if ( (c == c1 || c == c2 || f == c1 || f == c2)
-                            && (ln == len || ln == foldlen ||
-                                !ibcmp_utf8(s, do_utf8, (I32)(strend - s),
-                                            m, UTF, (I32)ln))
+                       if ( ((c == c1 || c == c2) && ln == len) ||
+                            ((f == c1 || f == c2) && ln == foldlen)
+                            || !ibcmp_utf8(s, do_utf8, (I32)(strend - s),
+                                           m, UTF, (I32)ln)
                             && (norun || regtry(prog, s)) )
                            goto got_it;
                        s += len;