handle bracket stack better in recdescent parsing

When recursing into the parser for recursive-descent parsing, put
a special entry on the bracket stack that generates a fake EOF if a
closing bracket belonging to an outer parser frame is seen.  This keeps
the bracket stack balanced across a parse_stmtseq() frame, fixing
[perl #78222].

If a recursive-descent parser frame ends by yyunlex()ing an opening
bracket, pop its entry off the bracket stack and stash it in the
forced-token queue, to be revived when the token is re-lexed.  This keeps
the bracket stack balanced across a parse_fullstmt() frame.

1 files changed, 2 insertions, 18 deletions

diff --git a/perly.y b/perly.y
index da7bcb07e3..cc27ee295a 100644
--- a/perly.y
+++ b/perly.y
@@ -89,7 +89,7 @@
 
 %type <i_tkval> lpar_or_qw
 
-%type <ival> grammar closebrace_or_eof prog progstart remember mremember
+%type <ival> grammar prog progstart remember mremember
 %type <ival>  startsub startanonsub startformsub
 /* FIXME for MAD - are these two ival? */
 %type <ival> mydefsv mintro
@@ -154,29 +154,13 @@ grammar	:	GRAMPROG prog
 			{
 			  parser->expect = XSTATE;
 			}
-		lineseq closebrace_or_eof
+		lineseq
 			{
 			  PL_eval_root = $3;
 			  $$ = 0;
 			}
 	;
 
-closebrace_or_eof:	'}'
-			{
-			  assert(parser->yychar == YYEMPTY);
-			  assert(parser->bufptr != SvPVX(parser->linestr));
-			  assert(parser->bufptr[-1] == '}');
-			  parser->bufptr--;
-			  parser->lex_brackstack[parser->lex_brackets++] =
-			      XSTATE;
-			  parser->expect = XSTATE;
-			  parser->yychar = YYEOF;
-			  $$ = 0;
-			}
-	| /* NULL */
-			{ $$ = 0; }
-	;
-
 /* The whole program */
 prog	:	progstart
 	/*CONTINUED*/	lineseq