Extend pg_cast castimplicit column to a three-way value; this allows us

to be flexible about assignment casts without introducing ambiguity in
operator/function resolution.  Introduce a well-defined promotion hierarchy
for numeric datatypes (int2->int4->int8->numeric->float4->float8).
Change make_const to initially label numeric literals as int4, int8, or
numeric (never float8 anymore).
Explicitly mark Func and RelabelType nodes to indicate whether they came
from a function call, explicit cast, or implicit cast; use this to do
reverse-listing more accurately and without so many heuristics.
Explicit casts to char, varchar, bit, varbit will truncate or pad without
raising an error (the pre-7.2 behavior), while assigning to a column without
any explicit cast will still raise an error for wrong-length data like 7.3.
This more nearly follows the SQL spec than 7.2 behavior (we should be
reporting a 'completion condition' in the explicit-cast cases, but we have
no mechanism for that, so just do silent truncation).
Fix some problems with enforcement of typmod for array elements;
it didn't work at all in 'UPDATE ... SET array[n] = foo', for example.
Provide a generalized array_length_coerce() function to replace the
specialized per-array-type functions that used to be needed (and were
missing for NUMERIC as well as all the datetime types).
Add missing conversions int8<->float4, text<->numeric, oid<->int8.
initdb forced.

src/backend/nodes/readfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.132 2002/09/04 20:31:20 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.133 2002/09/18 21:35:21 tgl Exp $
  *
  * NOTES
  *	  Most of the read functions for plan nodes are tested. (In fact, they
@@ -1129,6 +1129,10 @@ _readFunc(void)
 	token = pg_strtok(&length); /* now read it */
 	local_node->funcretset = strtobool(token);
 
+	token = pg_strtok(&length); /* get :funcformat */
+	token = pg_strtok(&length); /* now read it */
+	local_node->funcformat = (CoercionForm) atoi(token);
+
 	local_node->func_fcache = NULL;
 
 	return local_node;
@@ -1335,6 +1339,10 @@ _readRelabelType(void)
 	token = pg_strtok(&length); /* get resulttypmod */
 	local_node->resulttypmod = atoi(token);
 
+	token = pg_strtok(&length); /* eat :relabelformat */
+	token = pg_strtok(&length); /* get relabelformat */
+	local_node->relabelformat = (CoercionForm) atoi(token);
+
 	return local_node;
 }