Index: test/mmap1.test
==================================================================
--- test/mmap1.test
+++ test/mmap1.test
@@ -21,33 +21,37 @@
   array set stats [btree_pager_stats $bt]
   db_leave $db
   # puts [array get stats]
   return $stats(read)
 }
+
+proc register_rblob_code {dbname seed} {
+  return [subst -nocommands {
+    set ::rcnt $seed
+    proc rblob {n} {
+      set ::rcnt [expr (([set ::rcnt] << 3) + [set ::rcnt] + 456) & 0xFFFFFFFF]
+      set str [format %.8x [expr [set ::rcnt] ^ 0xbdf20da3]] 
+      string range [string repeat [set str] [expr [set n]/4]] 1 [set n]
+    }
+    $dbname func rblob rblob
+  }]
+}
 
 foreach {t mmap_limit nRead c2init} {
-  1.1 { PRAGMA mmap_limit = 67108864 }   4 {}
-  1.2 { PRAGMA mmap_limit =    53248 } 150 {}
-  1.3 { PRAGMA mmap_limit =        0 } 344 {}
+  1.1 { PRAGMA mmap_limit = 67108864 }   4 {PRAGMA mmap_limit = 0}
+  1.2 { PRAGMA mmap_limit =    53248 } 150 {PRAGMA mmap_limit = 0}
+  1.3 { PRAGMA mmap_limit =        0 } 344 {PRAGMA mmap_limit = 0}
   1.4 { PRAGMA mmap_limit = 67108864 }   4 {PRAGMA mmap_limit = 67108864 }
   1.5 { PRAGMA mmap_limit =    53248 } 150 {PRAGMA mmap_limit = 67108864 }
   1.6 { PRAGMA mmap_limit =        0 } 344 {PRAGMA mmap_limit = 67108864 }
 } {
   do_multiclient_test tn {
     sql1 {PRAGMA page_size=1024}
     sql1 $mmap_limit
     sql2 $c2init
 
-    code2 {
-      set ::rcnt 0
-      proc rblob {n} {
-        set ::rcnt [expr (($::rcnt << 3) + $::rcnt + 456) & 0xFFFFFFFF]
-        set str [format %.8x [expr $::rcnt ^ 0xbdf20da3]] 
-        string range [string repeat $str [expr $n/4]] 1 $n
-      }
-      db2 func rblob rblob
-    }
+    code2 [register_rblob_code db2 0]
 
     sql2 {
       PRAGMA page_size=1024;
       PRAGMA auto_vacuum = 1;
       CREATE TABLE t1(a, b, UNIQUE(a, b));
@@ -242,9 +246,70 @@
 } $bbb
 
 do_test 5.5 {
   sqlite3_finalize $::STMT
 } SQLITE_OK
+
+#-------------------------------------------------------------------------
+# Test various mmap_limit settings.
+#
+foreach {tn1 mmap1 mmap2} {
+     1 6144       167773
+     2 18432      140399
+     3 43008      401302
+     4 92160      253899
+     5 190464          2
+     6 387072     752431
+     7 780288     291143
+     8 1566720    594306
+     9 3139584    829137
+     10 6285312   793963
+     11 12576768 1015590
+} {
+  do_multiclient_test tn {
+    sql1 {
+      CREATE TABLE t1(a PRIMARY KEY);
+      CREATE TABLE t2(x);
+      INSERT INTO t2 VALUES('');
+    }
+
+    code1 [register_rblob_code db  0]
+    code2 [register_rblob_code db2 444]
+
+    sql1 "PRAGMA mmap_limit = $mmap1"
+    sql2 "PRAGMA mmap_limit = $mmap2"
+
+    do_test $tn1.$tn { 
+      for {set i 1} {$i <= 100} {incr i} {
+        if {$i % 2} {
+          set c1 sql1
+            set c2 sql2
+        } else {
+          set c1 sql2
+            set c2 sql1
+        }
+
+        $c1 {
+          INSERT INTO t1 VALUES( rblob(5000) );
+          UPDATE t2 SET x = (SELECT md5sum(a) FROM t1);
+        }
+
+        set res [$c2 { 
+            SELECT count(*) FROM t1;
+            SELECT x == (SELECT md5sum(a) FROM t1) FROM t2;
+            PRAGMA integrity_check;
+        }]
+        if {$res != [list $i 1 ok]} {
+          do_test $tn1.$tn.$i {
+            set ::res
+          } [list $i 1 ok]
+        }
+      }
+      set res 1
+    } {1}
+  }
+}
+
 
 finish_test