Fix a case where a checkpoint operation could write to an invalid part of a memory mapped region.

FossilOrigin-Name: 8dbe89d05ce91428c69003f0da79d883fa23e2b5

manifest

@@ -1,5 +1,5 @@
-C In\sthe\swinMremap\sVFS\sfunction,\sunmap\sthe\sregion\sprior\sto\sattempting\sto\struncate\sthe\sfile.
-D 2013-03-23T12:15:27.020
+C Fix\sa\scase\swhere\sa\scheckpoint\soperation\scould\swrite\sto\san\sinvalid\spart\sof\sa\smemory\smapped\sregion.
+D 2013-03-23T14:20:42.975
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 9a804abbd3cae82d196e4d33aba13239e32522a5
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -162,7 +162,7 @@ F src/os.h 8d92f87f5fe14b060a853ca704b8ef6d3daee79b
 F src/os_common.h 92815ed65f805560b66166e3583470ff94478f04
 F src/os_unix.c 55d110879332831b734fd510cfbc5700e96a83cf
 F src/os_win.c 386f8c034b177b672f7819ddc5d80be6c8d593ac
-F src/pager.c 12b8ff12519fe529a92884c4cdb99afecb1bea3c
+F src/pager.c cffcfe753445ef3a3d3830efd5f807fc171e7262
 F src/pager.h bbc9170281c9d5d603b2175fdc8ea908e47269a7
 F src/parse.y 5d5e12772845805fdfeb889163516b84fbb9ae95
 F src/pcache.c f8043b433a57aba85384a531e3937a804432a346
@@ -630,7 +630,7 @@ F test/misc5.test 528468b26d03303b1f047146e5eefc941b9069f5
 F test/misc6.test 953cc693924d88e6117aeba16f46f0bf5abede91
 F test/misc7.test dd82ec9250b89178b96cd28b2aca70639d21e5b3
 F test/misuse.test ba4fb5d1a6101d1c171ea38b3c613d0661c83054
-F test/mmap1.test 46ff4038b6d300bb9b39d3f89ea1aef3dff9b88f
+F test/mmap1.test e3391ef6c069e5f5733b8339652ce37fd97e3487
 F test/multiplex.test e08cc7177bd6d85990ee1d71100bb6c684c02256
 F test/multiplex2.test 580ca5817c7edbe4cc68fa150609c9473393003a
 F test/multiplex3.test d228f59eac91839a977eac19f21d053f03e4d101
@@ -730,7 +730,7 @@ F test/softheap1.test c16709a16ad79fa43b32929b2e623d1d117ccf53
 F test/sort.test 0e4456e729e5a92a625907c63dcdedfbe72c5dc5
 F test/speed1.test f2974a91d79f58507ada01864c0e323093065452
 F test/speed1p.explain d841e650a04728b39e6740296b852dccdca9b2cb
-F test/speed1p.test 2577211a9b054ffc973780f5b8708f02a0c7422d
+F test/speed1p.test c4a469f29f135f4d76c55b1f2a52f36e209466cc
 F test/speed2.test 53177056baf6556dcbdcf032bbdfc41c1aa74ded
 F test/speed3.test d32043614c08c53eafdc80f33191d5bd9b920523
 F test/speed4.test abc0ad3399dcf9703abed2fff8705e4f8e416715
@@ -1039,7 +1039,7 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P f57a9c91e993f76ce8b923e06e721414980e8e61
-R a68c203c916fb468751938d0762a7812
-U mistachkin
-Z c2b92e0c0a8c400cb287f5f47ed82e78
+P 8870c4cc6cda07154936644f7df25bd81d6ba38a
+R 0b90a49ac5025c5ac7d6b4eb49fe1878
+U dan
+Z c9ca2a38d0bbfc316a52f1d1e135baf9

manifest.uuid

@@ -1 +1 @@
-8870c4cc6cda07154936644f7df25bd81d6ba38a
+8dbe89d05ce91428c69003f0da79d883fa23e2b5

src/pager.c

@@ -4232,7 +4232,7 @@ static int syncJournal(Pager *pPager, int newHdr){
 */
 int sqlite3PagerSetFilesize(Pager *pPager, i64 szReq){
   int rc;
-  sqlite3_int64 sz;
+  i64 sz;                         /* Size of file on disk in bytes */
 
   assert( pPager->eState==PAGER_OPEN );
   assert( pPager->nMmapOut==0 );
@@ -4244,14 +4244,14 @@ int sqlite3PagerSetFilesize(Pager *pPager, i64 szReq){
     }
   }
 
-  if( rc==SQLITE_OK 
-   && pPager->nMapLimit>0 
-   && pPager->nMapValid<szReq 
-   && pPager->nMapValid<pPager->nMapLimit 
-  ){
+
+  if( rc==SQLITE_OK ){
+    i64 szMap = (szReq > pPager->nMapLimit) ? pPager->nMapLimit : szReq;
+    if( pPager->nMapValid!=pPager->nMap || szMap!=pPager->nMap ){
       pPager->dbFileSize = (szReq / pPager->pageSize);
       rc = pagerMap(pPager, 1);
     }
+  }
 
   return rc;
 }

test/mmap1.test

@@ -23,13 +23,17 @@ proc nRead {db} {
   return $stats(read)
 }
 
-foreach {t mmap_size nRead} {
-  1 { PRAGMA mmap_size = -65536 }   4
-  2 { PRAGMA mmap_size = -50    } 156
-  3 { PRAGMA mmap_size = 0      } 344
+foreach {t mmap_size nRead c2init} {
+  1.1 { PRAGMA mmap_size = -65536 }   4 {}
+  1.2 { PRAGMA mmap_size = -50    } 156 {}
+  1.3 { PRAGMA mmap_size = 0      } 344 {}
+  1.4 { PRAGMA mmap_size = -65536 }   4 {PRAGMA mmap_size = -65536}
+  1.5 { PRAGMA mmap_size = -50    } 156 {PRAGMA mmap_size = -65536}
+  1.6 { PRAGMA mmap_size = 0      } 344 {PRAGMA mmap_size = -65536}
 } {
   do_multiclient_test tn {
     sql1 $mmap_size
+    sql2 $c2init
 
     code2 {
       set ::rcnt 0
@@ -79,6 +83,51 @@ foreach {t mmap_size nRead} {
   }
 }
 
+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
+}
+
+reset_db
+db func rblob rblob
+
+do_execsql_test 2.1 {
+  PRAGMA auto_vacuum = 1;
+  PRAGMA mmap_size = -65536;
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(a, b, UNIQUE(a, b));
+  INSERT INTO t1 VALUES(rblob(500), rblob(500));
+  INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --    2
+  INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --    4
+  INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --    8
+  INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --   16
+  INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --   32
+  PRAGMA wal_checkpoint;
+} {wal 0 103 103}
+
+do_execsql_test 2.2 {
+  PRAGMA auto_vacuum;
+  SELECT count(*) FROM t1;
+} {1 32}
+
+do_test 2.3 {
+  sqlite3 db2 test.db
+  db2 func rblob rblob
+  db2 eval { 
+    DELETE FROM t1 WHERE (rowid%4);
+    PRAGMA wal_checkpoint;
+  }
+  db2 eval { 
+    INSERT INTO t1 SELECT rblob(500), rblob(500) FROM t1; --    16
+    SELECT count(*) FROM t1;
+  }
+} {16}
+
+do_execsql_test 2.4 {
+  PRAGMA wal_checkpoint;
+} {0 24 24}
 
 finish_test
 

test/speed1p.test

@@ -65,9 +65,6 @@ proc number_name {n} {
 #
 do_test speed1p-1.0 {
   execsql {
-    PRAGMA mmap_size=65536;
-    PRAGMA journal_mode=wal;
-
     PRAGMA page_size=1024;
     PRAGMA cache_size=500;
     PRAGMA locking_mode=EXCLUSIVE;