transformColumnDefinition failed to complain about

	create table foo (bar int default null default 3);
due to not thinking about the special-case handling of DEFAULT NULL.
Problem noticed while investigating bug #3396.

diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 2ad624c10821f2e71a7a3d48c39440d264dc75a9..a7bf9ab7f8b258c6ab31743d9d20c3d4691efdae 100644 (file)
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -956,6 +956,7 @@ transformColumnDefinition(ParseState *pstate, CreateStmtContext *cxt,
 {
        bool            is_serial;
        bool            saw_nullable;
+       bool            saw_default;
        Constraint *constraint;
        ListCell   *clist;
 
@@ -1086,6 +1087,7 @@ transformColumnDefinition(ParseState *pstate, CreateStmtContext *cxt,
        transformConstraintAttrs(column->constraints);
 
        saw_nullable = false;
+       saw_default = false;
 
        foreach(clist, column->constraints)
        {
@@ -1130,13 +1132,15 @@ transformColumnDefinition(ParseState *pstate, CreateStmtContext *cxt,
                                break;
 
                        case CONSTR_DEFAULT:
-                               if (column->raw_default != NULL)
+                               if (saw_default)
                                        ereport(ERROR,
                                                        (errcode(ERRCODE_SYNTAX_ERROR),
                                                         errmsg("multiple default values specified for column \"%s\" of table \"%s\"",
                                                                  column->colname, cxt->relation->relname)));
+                               /* Note: DEFAULT NULL maps to constraint->raw_expr == NULL */
                                column->raw_default = constraint->raw_expr;
                                Assert(constraint->cooked_expr == NULL);
+                               saw_default = true;
                                break;
 
                        case CONSTR_PRIMARY: