===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/commands/sequence.c,v
retrieving revision 1.117
diff -c -r1.117 sequence.c
*** src/backend/commands/sequence.c     16 Sep 2004 16:58:28 -0000      1.117
--- src/backend/commands/sequence.c     7 Nov 2004 22:05:01 -0000
***************
*** 608,613 ****
--- 608,642 ----
        PG_RETURN_INT64(result);
  }
  
+ Datum
+ currval_isset(PG_FUNCTION_ARGS)
+ {
+       text       *seqin = PG_GETARG_TEXT_P(0);
+       RangeVar   *sequence;
+       SeqTable        elm;
+       Relation        seqrel;
+ 
+       sequence = makeRangeVarFromNameList(textToQualifiedNameList(seqin,
+                                                                                                                        "currval"));
+ 
+       /* open and AccessShareLock sequence */
+       init_sequence(sequence, &elm, &seqrel);
+ 
+       if (pg_class_aclcheck(elm->relid, GetUserId(), ACL_SELECT) != ACLCHECK_OK)
+               ereport(ERROR,
+                               (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+                                errmsg("permission denied for sequence %s",
+                                               sequence->relname)));
+ 
+       if (elm->increment == 0) {      /* nextval/read_info were not called */
+           relation_close(seqrel, NoLock);
+           PG_RETURN_BOOL(false);
+       }
+ 
+       relation_close(seqrel, NoLock);
+       PG_RETURN_BOOL(true);
+ }
+ 
  /*
   * Main internal procedure that handles 2 & 3 arg forms of SETVAL.
   *
Index: src/include/catalog/pg_proc.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/catalog/pg_proc.h,v
retrieving revision 1.348
diff -c -r1.348 pg_proc.h
*** src/include/catalog/pg_proc.h       7 Oct 2004 18:38:50 -0000       1.348
--- src/include/catalog/pg_proc.h       7 Nov 2004 22:05:02 -0000
***************
*** 2034,2039 ****
--- 2034,2041 ----
  DESCR("sequence next value");
  DATA(insert OID = 1575 (  currval                     PGNSP PGUID 12 f f t f v 1 20 "25" _null_       currval - _null_ ));
  DESCR("sequence current value");
+ DATA(insert OID = 1295 (  currval_isset                       PGNSP PGUID 12 f f t f v 1 16 "25" _null_       currval_isset - _null_ ));
+ DESCR("sequence has current value");
  DATA(insert OID = 1576 (  setval                      PGNSP PGUID 12 f f t f v 2 20 "25 20" _null_  setval - _null_ ));
  DESCR("set sequence value");
  DATA(insert OID = 1765 (  setval                      PGNSP PGUID 12 f f t f v 3 20 "25 20 16" _null_ setval_and_iscalled - _null_ ));
Index: src/include/commands/sequence.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/commands/sequence.h,v
retrieving revision 1.29
diff -c -r1.29 sequence.h
*** src/include/commands/sequence.h     29 Aug 2004 04:13:05 -0000      1.29
--- src/include/commands/sequence.h     7 Nov 2004 22:05:02 -0000
***************
*** 82,87 ****
--- 82,88 ----
  
  extern Datum nextval(PG_FUNCTION_ARGS);
  extern Datum currval(PG_FUNCTION_ARGS);
+ extern Datum currval_isset(PG_FUNCTION_ARGS);
  extern Datum setval(PG_FUNCTION_ARGS);
  extern Datum setval_and_iscalled(PG_FUNCTION_ARGS);