From 5c9ae74dcaf4a16d67145fc3ea876a42aeb5c0b3 Mon Sep 17 00:00:00 2001
From: Father Chrysostomos <sprout@cpan.org>
Date: Wed, 8 Aug 2012 23:12:59 -0700
Subject: [PATCH] toke.c: Set PL_lex_state less when scanning formats
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This (in yylex) is the only code that calls scan_formline:

    case LEX_FORMLINE:
	PL_lex_state = PL_parser->form_lex_state;
	s = scan_formline(PL_bufptr);
	if (!PL_lex_formbrack)
	{
	    formbrack = 1;
	    goto rightbracket;
	}
	PL_bufptr = s;
	return yylex();
    }

It is only reached when PL_lex_state is LEX_FORMLINE.  scan_formline
itself does not even look at PL_lex_state.  It does set it, though,
unless it has reached the end of the format (setting PL_lex_formbrack
to 0) or the end of input.

This means we end up flipping it back and forth between two values.

We don’t have to set PL_lex_state before scan_formline() at all.  Hav-
ing scan_formline only set it when it does not need to be LEX_FORMLINE
simplifies things, resulting in less code and fewer assignments.
---
 toke.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/toke.c b/toke.c
index 49a29e6..2ecebad 100644
--- a/toke.c
+++ b/toke.c
@@ -4783,7 +4783,6 @@ Perl_yylex(pTHX)
 
 	return yylex();
     case LEX_FORMLINE:
-	PL_lex_state = PL_parser->form_lex_state;
 	s = scan_formline(PL_bufptr);
 	if (!PL_lex_formbrack)
 	{
@@ -10713,16 +10712,15 @@ S_scan_formline(pTHX_ register char *s)
 	incline(s);
     }
   enough:
+    if (!SvCUR(stuff) || needargs)
+	PL_lex_state = PL_parser->form_lex_state;
     if (SvCUR(stuff)) {
 	PL_expect = XSTATE;
 	if (needargs) {
-	    PL_lex_state = PL_parser->form_lex_state;
 	    start_force(PL_curforce);
 	    NEXTVAL_NEXTTOKE.ival = 0;
 	    force_next(FORMLBRACK);
 	}
-	else
-	    PL_lex_state = LEX_FORMLINE;
 	if (!IN_BYTES) {
 	    if (UTF && is_utf8_string((U8*)SvPVX_const(stuff), SvCUR(stuff)))
 		SvUTF8_on(stuff);
-- 
2.7.4