Allow unquoted UTF-8 HERE-document terminators

When not explicitly quoted, tokenization of the HERE-document terminator
dealt improperly with multi-byte characters, advancing one byte at a
time instead of one character at a time.  This lead to
incomprehensible-to-the-user errors of the form:

    Passing malformed UTF-8 to "XPosixWord" is deprecated
    Malformed UTF-8 character (unexpected continuation byte 0xa7, with
      no preceding start byte)
    Can't find string terminator "EnFra�" anywhere before EOF

If enclosed in single or double quotes, parsing was correctly effected,
as delimcpy advances byte-by-byte, but looks only for the single-byte
ending character.

When doing a \w+ match looking for the end of the word, advance
character-by-character instead of byte-by-byte, ensuring that the size
does not extend past the available size in PL_tokenbuf.

diff --git a/t/lib/warnings/toke b/t/lib/warnings/toke
index 018f188..b1d5347 100644 (file)
--- a/t/lib/warnings/toke
+++ b/t/lib/warnings/toke
@@ -1531,3 +1531,14 @@ my @array = (0);
 my $v = $array[ 0 + $𝛃 ];
    $v = $array[ $𝛃 + 0 ];
 EXPECT
+########
+# toke.c
+# Allow Unicode here doc boundaries
+use warnings;
+use utf8;
+my $v = <<EnFraçais;
+Comme ca!
+EnFraçais
+print $v;
+EXPECT
+Comme ca!

diff --git a/toke.c b/toke.c
index 56c5186..e8bb706 100644 (file)
--- a/toke.c
+++ b/toke.c
@@ -9210,10 +9210,14 @@ S_scan_heredoc(pTHX_ char *s)
            term = '"';
        if (!isWORDCHAR_lazy_if(s,UTF))
            deprecate("bare << to mean <<\"\"");
-       for (; isWORDCHAR_lazy_if(s,UTF); s++) {
-           if (d < e)
-               *d++ = *s;
+       peek = s;
+       while (isWORDCHAR_lazy_if(peek,UTF)) {
+           peek += UTF ? UTF8SKIP(peek) : 1;
        }
+       len = (peek - s >= e - d) ? (e - d) : (peek - s);
+       Copy(s, d, len, char);
+       s += len;
+       d += len;
     }
     if (d >= PL_tokenbuf + sizeof PL_tokenbuf - 1)
        Perl_croak(aTHX_ "Delimiter for here document is too long");