+AT_COMPILE([glr-regr15])
+
+AT_PARSER_CHECK([[./glr-regr15]], 0, [],
+[syntax is ambiguous
+])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Leaked lookahead after nondeterministic parse syntax error. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Leaked lookahead after nondeterministic parse syntax error])
+
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([glr-regr16.y],
+[[
+%glr-parser
+%destructor { lookahead_value = 0; } 'b'
+
+%{
+# include <stdlib.h>
+# include <assert.h>
+ ]AT_YYERROR_DECLARE[
+ ]AT_YYLEX_DECLARE[
+ static int lookahead_value = 0;
+# define USE(val)
+%}
+
+%%
+
+start: alt1 'a' | alt2 'a' ;
+alt1: ;
+alt2: ;
+
+%%
+
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE(["ab"],
+ [if (res == 'b')
+ lookahead_value = 1])[
+
+int
+main (void)
+{
+ int exit_status = yyparse () != 1;
+ if (lookahead_value)
+ {
+ fprintf (stderr, "Lookahead destructor not called.\n");
+ exit_status = 1;
+ }
+ return exit_status;
+}
+]])
+AT_BISON_OPTION_POPDEFS
+
+AT_BISON_CHECK([[-o glr-regr16.c glr-regr16.y]], 0, [],
+[glr-regr16.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr16])
+
+AT_PARSER_CHECK([[./glr-regr16]], 0, [],
+[syntax error
+])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Uninitialized location when reporting ambiguity. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Uninitialized location when reporting ambiguity])
+
+AT_BISON_OPTION_PUSHDEFS([%glr-parser %locations %define api.pure])
+
+AT_DATA_GRAMMAR([glr-regr17.y],
+[[
+%glr-parser
+%locations
+%define api.pure
+%error-verbose
+
+%union { int dummy; }
+
+%{
+ ]AT_YYERROR_DECLARE[
+ ]AT_YYLEX_DECLARE[
+%}
+
+%initial-action {
+ @$.first_line = 1;
+ @$.first_column = 1;
+ @$.last_line = 1;
+ @$.last_column = 1;
+}
+
+%%
+
+/* Tests the case of an empty RHS that has inherited the location of the
+ previous nonterminal, which is unresolved. That location is reported as the
+ last position of the ambiguity. */
+start: ambig1 empty1 | ambig2 empty2 ;
+
+/* Tests multiple levels of yyresolveLocations recursion. */
+ambig1: sub_ambig1 | sub_ambig2 ;
+ambig2: sub_ambig1 | sub_ambig2 ;
+
+/* Tests the case of a non-empty RHS as well as the case of an empty RHS that
+ has inherited the initial location. The empty RHS's location is reported as
+ the first position in the ambiguity. */
+sub_ambig1: empty1 'a' 'b' ;
+sub_ambig2: empty2 'a' 'b' ;
+empty1: ;
+empty2: ;
+
+%%
+# include <assert.h>
+
+]AT_YYERROR_DEFINE[
+static int
+yylex (YYSTYPE *lvalp, YYLTYPE *llocp)
+{
+ static char const input[] = "ab";
+ static size_t toknum;
+ assert (toknum < sizeof input);
+ lvalp->dummy = 0;
+ llocp->first_line = llocp->last_line = 2;
+ llocp->first_column = toknum + 1;
+ llocp->last_column = llocp->first_column + 1;
+ return input[toknum++];
+}
+
+int
+main (void)
+{
+ return yyparse () != 1;
+}
+]])
+AT_BISON_OPTION_POPDEFS
+
+AT_BISON_CHECK([[-o glr-regr17.c glr-regr17.y]], 0, [],
+[glr-regr17.y: conflicts: 3 reduce/reduce
+])
+AT_COMPILE([glr-regr17])
+
+AT_PARSER_CHECK([[./glr-regr17]], 0, [],
+[1.1-2.2: syntax is ambiguous
+])
+
+AT_CLEANUP
+