Ensure that typmod decoration on a datatype name is validated in all cases,

even in code paths where we don't pay any subsequent attention to the typmod
value.  This seems needed in view of the fact that 8.3's generalized typmod
support will accept a lot of bogus syntax, such as "timestamp(foo)" or
"record(int, 42)" --- if we allow such things to pass without comment,
users will get confused.  Per a recent example from Greg Stark.

To implement this in a way that's not very vulnerable to future
bugs-of-omission, refactor the API of parse_type.c's TypeName lookup routines
so that typmod validation is folded into the base lookup operation.  Callers
can still choose not to receive the encoded typmod, but we'll check the
decoration anyway if it's present.

1 files changed, 8 insertions, 15 deletions

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 0af90cb4ac6..23f36193690 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.234 2007/10/12 18:55:12 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.235 2007/11/11 19:22:48 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -899,8 +899,7 @@ MergeAttributes(List *schema, List *supers, bool istemp,
 						(errmsg("merging multiple inherited definitions of column \"%s\"",
 								attributeName)));
 				def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
-				defTypeId = typenameTypeId(NULL, def->typename);
-				deftypmod = typenameTypeMod(NULL, def->typename, defTypeId);
+				defTypeId = typenameTypeId(NULL, def->typename, &deftypmod);
 				if (defTypeId != attribute->atttypid ||
 					deftypmod != attribute->atttypmod)
 					ereport(ERROR,
@@ -1044,10 +1043,8 @@ MergeAttributes(List *schema, List *supers, bool istemp,
 				   (errmsg("merging column \"%s\" with inherited definition",
 						   attributeName)));
 				def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
-				defTypeId = typenameTypeId(NULL, def->typename);
-				deftypmod = typenameTypeMod(NULL, def->typename, defTypeId);
-				newTypeId = typenameTypeId(NULL, newdef->typename);
-				newtypmod = typenameTypeMod(NULL, newdef->typename, newTypeId);
+				defTypeId = typenameTypeId(NULL, def->typename, &deftypmod);
+				newTypeId = typenameTypeId(NULL, newdef->typename, &newtypmod);
 				if (defTypeId != newTypeId || deftypmod != newtypmod)
 					ereport(ERROR,
 							(errcode(ERRCODE_DATATYPE_MISMATCH),
@@ -3018,8 +3015,7 @@ ATExecAddColumn(AlteredTableInfo *tab, Relation rel,
 			int32 	ctypmod;
 
 			/* Okay if child matches by type */
-			ctypeId = typenameTypeId(NULL, colDef->typename);
-			ctypmod = typenameTypeMod(NULL, colDef->typename, ctypeId);
+			ctypeId = typenameTypeId(NULL, colDef->typename, &ctypmod);
 			if (ctypeId != childatt->atttypid ||
 				ctypmod != childatt->atttypmod)
 				ereport(ERROR,
@@ -3074,10 +3070,9 @@ ATExecAddColumn(AlteredTableInfo *tab, Relation rel,
 						MaxHeapAttributeNumber)));
 	i = minattnum + 1;
 
-	typeTuple = typenameType(NULL, colDef->typename);
+	typeTuple = typenameType(NULL, colDef->typename, &typmod);
 	tform = (Form_pg_type) GETSTRUCT(typeTuple);
 	typeOid = HeapTupleGetOid(typeTuple);
-	typmod = typenameTypeMod(NULL, colDef->typename, typeOid);
 
 	/* make sure datatype is legal for a column */
 	CheckAttributeType(colDef->colname, typeOid);
@@ -4777,8 +4772,7 @@ ATPrepAlterColumnType(List **wqueue,
 						colName)));
 
 	/* Look up the target type */
-	targettype = typenameTypeId(NULL, typename);
-	targettypmod = typenameTypeMod(NULL, typename, targettype);
+	targettype = typenameTypeId(NULL, typename, &targettypmod);
 
 	/* make sure datatype is legal for a column */
 	CheckAttributeType(colName, targettype);
@@ -4905,10 +4899,9 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 						colName)));
 
 	/* Look up the target type (should not fail, since prep found it) */
-	typeTuple = typenameType(NULL, typename);
+	typeTuple = typenameType(NULL, typename, &targettypmod);
 	tform = (Form_pg_type) GETSTRUCT(typeTuple);
 	targettype = HeapTupleGetOid(typeTuple);
-	targettypmod = typenameTypeMod(NULL, typename, targettype);
 
 	/*
 	 * If there is a default expression for the column, get it and ensure we