Index: src/expr.c
==================================================================
--- src/expr.c
+++ src/expr.c
@@ -1653,10 +1653,11 @@
 
         assert( !isRowid );
         sqlite3SelectDestInit(&dest, SRT_Set, pExpr->iTable);
         dest.affinity = (u8)affinity;
         assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
+        pExpr->x.pSelect->iLimit = 0;
         if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){
           return 0;
         }
         pEList = pExpr->x.pSelect->pEList;
         if( ALWAYS(pEList!=0 && pEList->nExpr>0) ){ 
@@ -1753,10 +1754,11 @@
         VdbeComment((v, "Init EXISTS result"));
       }
       sqlite3ExprDelete(pParse->db, pSel->pLimit);
       pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0,
                                   &sqlite3IntTokens[1]);
+      pSel->iLimit = 0;
       if( sqlite3Select(pParse, pSel, &dest) ){
         return 0;
       }
       rReg = dest.iParm;
       ExprSetIrreducible(pExpr);
@@ -3031,20 +3033,32 @@
     pExpr->iTable = r2;
     return WRC_Prune;
   }
   return WRC_Continue;
 }
+
+/* This routine is part of the parse-tree walker for
+** sqlite3ExprCodeConstants().  Simply return WRC_Continue so that
+** tree walker logic will extend constant extraction and precoding
+** into subqueires.
+*/
+static int evalConstSelect(Walker *pNotUsed1, Select *pNotUsed2){
+  UNUSED_PARAMETER(pNotUsed1);
+  UNUSED_PARAMETER(pNotUsed2);
+  return WRC_Continue;
+}
 
 /*
 ** Preevaluate constant subexpressions within pExpr and store the
 ** results in registers.  Modify pExpr so that the constant subexpresions
 ** are TK_REGISTER opcodes that refer to the precomputed values.
 */
 void sqlite3ExprCodeConstants(Parse *pParse, Expr *pExpr){
   Walker w;
+  if( pParse->cookieGoto ) return;
   w.xExprCallback = evalConstExpr;
-  w.xSelectCallback = 0;
+  w.xSelectCallback = evalConstSelect;
   w.pParse = pParse;
   sqlite3WalkExpr(&w, pExpr);
 }
 
 

ADDED   test/tkt-80ba201079.test
Index: test/tkt-80ba201079.test
==================================================================
--- test/tkt-80ba201079.test
+++ test/tkt-80ba201079.test
@@ -0,0 +1,96 @@
+# 2010 December 6
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library. Specifically,
+# it tests that ticket [80ba201079ea608071d22a57856b940ea3ac53ce] is
+# resolved.  That ticket is about an incorrect result that appears when
+# an index is added.  The root cause is that a constant is being used
+# without initialization when the OR optimization applies in the WHERE clause.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+do_test tkt-80ba2-100 {
+  db eval {
+    CREATE TABLE t1(a);
+    INSERT INTO t1 VALUES('A');
+    CREATE TABLE t2(b);
+    INSERT INTO t2 VALUES('B');
+    CREATE TABLE t3(c);
+    INSERT INTO t3 VALUES('C');
+    SELECT * FROM t1, t2
+     WHERE (a='A' AND b='X')
+        OR (a='A' AND EXISTS (SELECT * FROM t3 WHERE c='C'));
+  }
+} {A B}
+do_test tkt-80ba2-101 {
+  db eval {
+    CREATE INDEX i1 ON t1(a);
+    SELECT * FROM t1, t2
+     WHERE (a='A' AND b='X')
+        OR (a='A' AND EXISTS (SELECT * FROM t3 WHERE c='C'));
+  }
+} {A B}
+
+do_test tkt-80ba2-200 {
+  db eval {
+    CREATE TABLE entry_types (
+                        id     integer primary key,
+                        name   text
+                    );
+    INSERT INTO "entry_types" VALUES(100,'cli_command');
+    INSERT INTO "entry_types" VALUES(300,'object_change');
+    CREATE TABLE object_changes (
+                        change_id    integer primary key,
+                        system_id    int,
+                        obj_id       int,
+                        obj_context  text,
+                        change_type  int,
+                        command_id   int
+                    );
+    INSERT INTO "object_changes" VALUES(1551,1,114608,'exported_pools',1,2114);
+    INSERT INTO "object_changes" VALUES(2048,1,114608,'exported_pools',2,2319);
+    CREATE TABLE timeline (
+                        rowid        integer primary key,
+                        timestamp    text,
+                        system_id    int,
+                        entry_type   int,
+                        entry_id     int
+                    );
+    INSERT INTO "timeline" VALUES(6735,'2010-11-21 17:08:27.000',1,300,2048);
+    INSERT INTO "timeline" VALUES(6825,'2010-11-21 17:09:21.000',1,300,2114);
+    SELECT entry_type,
+           entry_types.name,
+           entry_id
+      FROM timeline JOIN entry_types ON entry_type = entry_types.id
+     WHERE (entry_types.name = 'cli_command' AND entry_id=2114)
+        OR (entry_types.name = 'object_change'
+             AND entry_id IN (SELECT change_id
+                              FROM object_changes
+                               WHERE obj_context = 'exported_pools'));
+  }
+} {300 object_change 2048}
+do_test tkt-80ba2-201 {
+  db eval {
+    CREATE INDEX timeline_entry_id_idx on timeline(entry_id);
+    SELECT entry_type,
+           entry_types.name,
+           entry_id
+      FROM timeline JOIN entry_types ON entry_type = entry_types.id
+     WHERE (entry_types.name = 'cli_command' AND entry_id=2114)
+        OR (entry_types.name = 'object_change'
+             AND entry_id IN (SELECT change_id
+                              FROM object_changes
+                               WHERE obj_context = 'exported_pools'));
+  }
+} {300 object_change 2048}
+
+finish_test