[perl #88420] BOM support on Windows broken in 5.13.11

When Perl reads the script in text mode, then the tell() position
on the script handle may include stripped carriage return characters.
Therefore the file position after reading the first line of the
script may be one larger than the length of the input buffer.

1 files changed, 7 insertions, 1 deletions

diff --git a/toke.c b/toke.c
index c4cda7b324..0f08d42ab4 100644
--- a/toke.c
+++ b/toke.c
@@ -4792,7 +4792,13 @@ Perl_yylex(pTHX)
 		      *(U8*)s == 0xEF ||
 		      *(U8*)s >= 0xFE ||
 		      s[1] == 0)) {
-		bof = PerlIO_tell(PL_rsfp) == (Off_t)SvCUR(PL_linestr);
+		IV offset = (IV)PerlIO_tell(PL_rsfp);
+		bof = (offset == SvCUR(PL_linestr));
+#if defined(PERLIO_USING_CRLF) && defined(PERL_TEXTMODE_SCRIPTS)
+		/* offset may include swallowed CR */
+		if (!bof)
+		    bof = (offset == SvCUR(PL_linestr)+1);
+#endif
 		if (bof) {
 		    PL_bufend = SvPVX(PL_linestr) + SvCUR(PL_linestr);
 		    s = swallow_bom((U8*)s);