Fix crash in refactored lexer internals

Commit f0e67a1d29102aa9905aecf2b0f98449697d5af3 changed the control
flow so that PerlIO_tell(PL_rsfp) could be called when PL_rsfp was
NULL, which produces a crash at least on Windows with the MSVCRT
runtime.

This change moves the detection if PL_rsfp is NULL or not closer to
the location where is is actually tested, which gets rid of the
crashes.  I however have *not* verified if the changes in control
flow in f0e67a1d are otherwise correct or not.

diff --git a/toke.c b/toke.c
index 6793f7b..6b5ef4f 100644 (file)
--- a/toke.c
+++ b/toke.c
@@ -4315,7 +4315,6 @@ Perl_yylex(pTHX)
        }
        do {
            U32 fake_eof = 0;
-           bof = PL_rsfp ? TRUE : FALSE;
            if (0) {
              fake_eof:
                fake_eof = LEX_FAKE_EOF;
@@ -4332,6 +4331,7 @@ Perl_yylex(pTHX)
            s = PL_bufptr;
            /* If it looks like the start of a BOM or raw UTF-16,
             * check if it in fact is. */
+           bof = PL_rsfp ? TRUE : FALSE;
            if (bof &&
                     (*s == 0 ||
                      *(U8*)s == 0xEF ||