* data/glr.c (YY_SYMBOL_PRINT): Don't print newline at end to

fix a small glitch in debugging output.
(yyprocessOneStack, yyrecoverSyntaxError, yyparse): Print newline
after YY_SYMBOL_PRINT where needed.

(struct yyGLRState): Add some comments.
(struct yySemanticOption): Add some comments.
(union yyGLRStackItem): Add comment.

(yymergeOptionSets): Correct this to properly perform the union,
avoiding infinite reported by Michael Rosien.
Update comment.

* tests/glr-regression.at: Add test for GLR merging error reported
by M. Rosien.

tests/glr-regression.at

@@ -221,4 +221,106 @@ AT_CHECK([[echo s VARIABLE_3 t v x | ./glr-regr2a]], 0,
 ]], [])
 
 
+AT_CLEANUP
+
+## ------------------------------------------------------------ ##
+## Improper merging of GLR delayed action sets                  ##
+## ------------------------------------------------------------ ##
+
+AT_SETUP([Improper merging of GLR delayed action sets])
+
+AT_DATA_GRAMMAR([glr-regr3.y],
+[[/* Regression Test: Improper merging of GLR delayed action sets.  */
+/* Reported by M. Rosien */
+
+%{
+#include <stdio.h>
+#include <stdarg.h>
+
+static int MergeRule (int x0, int x1);
+static void yyerror(char const * s);
+
+#define RULE(x) (1 << (x))
+
+%}
+
+%glr-parser
+
+%token BAD_CHAR
+%token P1 P2 T1 T2 T3 T4 O1 O2
+
+%%
+
+S : P1 T4 O2 NT6 P2  { printf ("Result: %x\n", $4); }
+;
+
+NT1 : P1 T1 O1 T2 P2 { $$ = RULE(2); }  %merge<MergeRule>
+;
+
+NT2 : NT1             { $$ = RULE(3); } %merge<MergeRule>
+    | P1 NT1 O1 T3 P2 { $$ = RULE(4); } %merge<MergeRule>
+;
+
+NT3 : T3              { $$ = RULE(5); } %merge<MergeRule>
+    | P1 NT1 O1 T3 P2 { $$ = RULE(6); } %merge<MergeRule>
+;
+
+NT4 : NT3              { $$ = RULE(7); } %merge<MergeRule>
+    | NT2              { $$ = RULE(8); } %merge<MergeRule>
+    | P1 NT2 O1 NT3 P2 { $$ = RULE(9); } %merge<MergeRule>
+;
+
+NT5 : NT4              { $$ = RULE(10); } %merge<MergeRule>
+;
+
+NT6 : P1 NT1 O1 T3 P2  { $$ = RULE(11) | $2; } %merge<MergeRule>
+    | NT5              { $$ = RULE(12) | $1; } %merge<MergeRule>
+;
+
+%%
+
+static int MergeRule (int x0, int x1) {
+  return x0 | x1;
+}
+
+static void yyerror(char const * s) {
+  fprintf(stderr,"error: %s\n",s);
+}
+
+FILE *yyin = NULL;
+
+int P[] = { P1, P2 };
+int O[] = { O1, O2 };
+int T[] = { T1, T2, T3, T4 };
+
+int yylex (void)
+{
+  char inp[3];
+  if (fscanf (yyin, "%2s", inp) == EOF)
+    return 0;
+  switch (inp[0]) 
+    {
+    case 'p': return P[inp[1] - '1'];
+    case 't': return T[inp[1] - '1'];
+    case 'o': return O[inp[1] - '1'];
+    }
+  return BAD_CHAR;
+}
+
+int main(int argc, char* argv[]) {
+  yyin = stdin;
+  if (argc == 2 && !(yyin = fopen (argv[1], "r"))) return 1;
+  return yyparse ();
+}
+]])
+
+AT_CHECK([[bison -o glr-regr3.c glr-regr3.y]], 0, [],
+[glr-regr3.y: conflicts: 1 shift/reduce, 1 reduce/reduce
+])
+AT_COMPILE([glr-regr3])
+
+AT_CHECK([[echo p1 t4 o2 p1 p1 t1 o1 t2 p2 o1 t3 p2 p2 | ./glr-regr3]], 0,
+[[Result: 1c04
+]], [])
+
 AT_CLEANUP