Fix multiple performance regressions (ticket #2298 among them)

and add tests to make sure they do not come back. (CVS 3839)

FossilOrigin-Name: 32bb2d5859906b4fb0f6083eedd7f3a81b9cf5e2

test/ioerr2.test

@@ -15,7 +15,7 @@
 # The tests in this file use special facilities that are only
 # available in the SQLite test fixture.
 #
-# $Id: ioerr2.test,v 1.3 2007/04/09 12:45:03 drh Exp $
+# $Id: ioerr2.test,v 1.4 2007/04/13 02:14:30 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -82,10 +82,11 @@ set sql {
   ROLLBACK;
 }
 
-breakpoint
 foreach bPersist [list 0 1] {
   set ::go 1
   for {set ::N 1} {$::go} {incr ::N} {
+    db close
+    sqlite3 db test.db
     set ::sqlite_io_error_hit 0
     set ::sqlite_io_error_persist $bPersist
     set ::sqlite_io_error_pending $::N
@@ -94,5 +95,16 @@ foreach bPersist [list 0 1] {
     check_db ioerr2-3.$bPersist.$::N
   }
 }
+foreach bPersist [list 0 1] {
+  set ::go 1
+  for {set ::N 1} {$::go} {incr ::N} {
+    set ::sqlite_io_error_hit 0
+    set ::sqlite_io_error_persist $bPersist
+    set ::sqlite_io_error_pending $::N
+
+    foreach {::go res} [catchsql $sql] {}
+    check_db ioerr2-3.[expr {$bPersist+2}].$::N
+  }
+}
 
 finish_test