Document the final sigma spot.

p4raw-id: //depot/perl@12602

diff --git a/pp.c b/pp.c
index 3d93f75..a0729e9 100644 (file)
--- a/pp.c
+++ b/pp.c
@@ -3277,7 +3277,7 @@ PP(pp_uc)
            d = (U8*)SvPVX(TARG);
            send = s + len;
            while (s < send) {
-               toUPPER_utf8(s, tmpbuf, &ulen);
+               toUPPER_utf8(s, tmpbuf, &ulen);
                Copy(tmpbuf, d, ulen, U8);
                d += ulen;
                s += UTF8SKIP(s);
@@ -3344,7 +3344,24 @@ PP(pp_lc)
            d = (U8*)SvPVX(TARG);
            send = s + len;
            while (s < send) {
-               toLOWER_utf8(s, tmpbuf, &ulen);
+               UV uv = toLOWER_utf8(s, tmpbuf, &ulen);
+#define GREEK_CAPITAL_LETTER_SIGMA 0x03A3 /* Unicode */
+               if (uv == GREEK_CAPITAL_LETTER_SIGMA) {
+                    /*
+                     * Now if the sigma is NOT followed by
+                     * /$ignorable_sequence$cased_letter/;
+                     * and it IS preceded by
+                     * /$cased_letter$ignorable_sequence/;
+                     * where $ignorable_sequence is
+                     * [\x{2010}\x{AD}\p{Mn}]*
+                     * and $cased_letter is
+                     * [\p{Ll}\p{Lo}\p{Lt}]
+                     * then it should be mapped to 0x03C2,
+                     * (GREEK SMALL LETTER FINAL SIGMA),
+                     * instead of staying 0x03A3.
+                     * See lib/unicore/SpecCase.txt.
+                     */
+               }
                Copy(tmpbuf, d, ulen, U8);
                d += ulen;
                s += UTF8SKIP(s);