Correct coredump in ALTER TABLE foo ADD(). Accept explicit NULL in

typecasts, eg 'NULL::text'.  Later parts of the parser don't like this
yet, but I'll work on that next.

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index ce16f9e..b7724b7 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.117 1999/12/06 18:02:43 wieck Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.118 1999/12/10 03:01:05 tgl Exp $
  *
  * HISTORY
  *       AUTHOR                        DATE                    MAJOR EVENT
@@ -362,7 +362,7 @@ static Node *doNegate(Node *n);
 %right         UMINUS
 %left          '.'
 %left          '[' ']'
-%nonassoc      TYPECAST
+%left          TYPECAST
 %left          UNION INTERSECT EXCEPT
 %%
 
@@ -759,11 +759,9 @@ alter_clause:  ADD opt_column columnDef
                                }
                        | ADD '(' OptTableElementList ')'
                                {
-                                       Node *lp = lfirst($3);
-
                                        if (length($3) != 1)
                                                elog(ERROR,"ALTER TABLE/ADD() allows one column only");
-                                       $$ = lp;
+                                       $$ = (Node *) lfirst($3);
                                }
                        | DROP opt_column ColId
                                {       elog(ERROR,"ALTER TABLE/DROP COLUMN not yet implemented"); }
@@ -1532,7 +1530,7 @@ ConstraintTimeSpec: INITIALLY IMMEDIATE
                | INITIALLY DEFERRED
                        { $$ = 2; }
                ;
-               
+
 
 DropTrigStmt:  DROP TRIGGER name ON relation_name
                                {
@@ -1758,7 +1756,7 @@ comment_tg:       TRIGGER { $$ = TRIGGER; }
                ; 
 
 comment_text:  Sconst { $$ = $1; }
-               | NULL_P { $$ = 0; }
+               | NULL_P { $$ = NULL; }
                ;
                
 /*****************************************************************************
@@ -3808,6 +3806,17 @@ a_expr:  com_expr
                                        }
                                }
                /*
+                * Can't collapse this into prior rule by using a_expr_or_null;
+                * that creates reduce/reduce conflicts.  Grumble.
+                */
+               | NULL_P TYPECAST Typename
+                               {
+                                       A_Const *n = makeNode(A_Const);
+                                       n->val.type = T_Null;
+                                       n->typename = $3;
+                                       $$ = (Node *)n;
+                               }
+               /*
                 * These operators must be called out explicitly in order to make use
                 * of yacc/bison's automatic operator-precedence handling.  All other
                 * operator names are handled by the generic productions using "Op",
@@ -4041,6 +4050,13 @@ b_expr:  com_expr
                                                $$ = (Node *)n;
                                        }
                                }
+               | NULL_P TYPECAST Typename
+                               {
+                                       A_Const *n = makeNode(A_Const);
+                                       n->val.type = T_Null;
+                                       n->typename = $3;
+                                       $$ = (Node *)n;
+                               }
                | '-' b_expr %prec UMINUS
                                {       $$ = doNegate($2); }
                | '%' b_expr
@@ -4110,7 +4126,7 @@ com_expr:  attr
                                {       $$ = $1;  }
                | '(' a_expr_or_null ')'
                                {       $$ = $2; }
-               | CAST '(' a_expr AS Typename ')'
+               | CAST '(' a_expr_or_null AS Typename ')'
                                {
                                        $$ = (Node *)$3;
                                        /* AexprConst can be either A_Const or ParamNo */
@@ -4870,7 +4886,7 @@ ColId:  IDENT                                                     { $$ = $1; }
                | STATEMENT                                             { $$ = "statement"; }
                | STDIN                                                 { $$ = "stdin"; }
                | STDOUT                                                { $$ = "stdout"; }
-                | SYSID                                                 { $$ = "sysid"; }
+               | SYSID                                                 { $$ = "sysid"; }
                | TIME                                                  { $$ = "time"; }
                | TIMESTAMP                                             { $$ = "timestamp"; }
                | TIMEZONE_HOUR                                 { $$ = "timezone_hour"; }