From: dan <dan@noemail.net>
Date: Thu, 20 Aug 2015 20:25:56 +0000 (+0000)
Subject: Fix a problem causing corruption when an UNLOCKED transaction is rolled back.
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=699bdf056b62070d2cf5d47b8678ddf4bcb72479;p=thirdparty%2Fsqlite.git

Fix a problem causing corruption when an UNLOCKED transaction is rolled back.

FossilOrigin-Name: 7c36147846484c96023939864417b5624f3bc5f8
---

diff --git a/manifest b/manifest
index 92f5317a3d..ba7247bf36 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C When\scommitting\san\sunlocked\stransaction,\srelocate\snewly\sallocated\sdatabase\spages\swithin\sthe\sfile\sto\savoid\sconflicting\swith\scommitted\stransactions.\sThere\sare\slots\sof\sthings\sstill\sto\sfix\sin\sthis\scode.
-D 2015-08-19T20:27:05.840
+C Fix\sa\sproblem\scausing\scorruption\swhen\san\sUNLOCKED\stransaction\sis\srolled\sback.
+D 2015-08-20T20:25:56.029
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 4de3ef40c8b3b75c0c55ff4242a43c8ce1ad90ee
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -315,7 +315,7 @@ F src/os_setup.h c9d4553b5aaa6f73391448b265b89bed0b890faa
 F src/os_unix.c 388c023582b17890f10c980b30ec1922b471753b
 F src/os_win.c 40b3af7a47eb1107d0d69e592bec345a3b7b798a
 F src/os_win.h eb7a47aa17b26b77eb97e4823f20a00b8bda12ca
-F src/pager.c fe82e368600278cfd35024c20b888e945236f675
+F src/pager.c 48a76f16a75112c9b064e21e1d1ecf0b4d87b5cd
 F src/pager.h 3fc23bca2e7d606ca4fbdd923713cdcdcec48297
 F src/parse.y 199145cd982587d70fa3db2f9b11f7ab118f0acd
 F src/pcache.c cde06aa50962595e412d497e22fd2e07878ba1f0
@@ -1216,7 +1216,7 @@ F test/unique.test 93f8b2ef5ea51b9495f8d6493429b1fd0f465264
 F test/unique2.test 41e7f83c6827605991160a31380148a9fc5f1339
 F test/unixexcl.test cd6c765f75e50e8e2c2ba763149e5d340ea19825
 F test/unlocked.test d143a871bd874311d4e5c98ce458218ca6b579fd
-F test/unlocked2.test fc4c730a44c3650250467ecacca6ddb969f64405
+F test/unlocked2.test 06a7d5a366bfc6fcaf472a2411f6d45fd9255ed4
 F test/unordered.test ca7adce0419e4ca0c50f039885e76ed2c531eda8
 F test/update.test 6c68446b8a0a33d522a7c72b320934596a2d7d32
 F test/uri.test 23662b7b61958b0f0e47082de7d06341ccf85d5b
@@ -1368,7 +1368,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P de1ea450db33b140b11af5b801ea6a15875e774e
-R db05422c8fb37e882a7e6cc4bd7c8ffb
+P 3bbc31d515ba9fc920c5cbc7059d3eb1ba9c7f8e
+R 9ac18b47cee85e97c9fcd4362b958c7d
 U dan
-Z cccfd407eb244cf1cd3b5cab72e65fda
+Z 032a41c4b1c95657db216d02c5116d23
diff --git a/manifest.uuid b/manifest.uuid
index 7d70f3c411..ce9cb89059 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3bbc31d515ba9fc920c5cbc7059d3eb1ba9c7f8e
\ No newline at end of file
+7c36147846484c96023939864417b5624f3bc5f8
\ No newline at end of file
diff --git a/src/pager.c b/src/pager.c
index efbea0ab8e..ac2f6bf1a6 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -3021,6 +3021,7 @@ static int pagerUndoCallback(void *pCtx, Pgno iPg){
 static int pagerRollbackWal(Pager *pPager){
   int rc;                         /* Return Code */
   PgHdr *pList;                   /* List of dirty pages to revert */
+  int bPage1 = 0;                 /* True if page 1 has been undone */
 
   /* For all pages in the cache that are currently dirty or have already
   ** been written (but not committed) to the log file, do one of the 
@@ -3034,10 +3035,18 @@ static int pagerRollbackWal(Pager *pPager){
   pList = sqlite3PcacheDirtyList(pPager->pPCache);
   while( pList && rc==SQLITE_OK ){
     PgHdr *pNext = pList->pDirty;
+    if( pList->pgno==1 ) bPage1 = 1;
     rc = pagerUndoCallback((void *)pPager, pList->pgno);
     pList = pNext;
   }
 
+  /* If this is an UNLOCKED transaction, then page 1 must be reread from the
+  ** db file, even if it is not dirty. This is because the b-tree layer may
+  ** have already zeroed the nFree and iTrunk header fields.  */
+  if( rc==SQLITE_OK && bPage1==0 && pPager->pAllRead ){
+    rc = pagerUndoCallback((void*)pPager, 1);
+  }
+
   return rc;
 }
 
diff --git a/test/unlocked2.test b/test/unlocked2.test
index f808a84e7b..e9c62194a0 100644
--- a/test/unlocked2.test
+++ b/test/unlocked2.test
@@ -90,12 +90,72 @@ do_multiclient_test tn {
     sql2 {
       INSERT INTO t2 VALUES(randomblob(1500));
     }
+    sql1 COMMIT
+  } {}
+
+  do_test 2.$tn.3 { sql3 { PRAGMA integrity_check } } {ok}
+
+  do_test 2.$tn.4  {
+    sql1 { 
+      BEGIN UNLOCKED;
+        DELETE FROM t1;
+    }
+    sql2 {
+      DELETE FROM t2;
+    }
+    sql1 COMMIT
+  } {}
+
+  do_test 2.$tn.5 { sql3 { PRAGMA integrity_check } } {ok}
+
+  do_test 2.$tn.6 {
     sql1 {
-      COMMIT;
+      INSERT INTO t1 VALUES(randomblob(1500));
+      INSERT INTO t1 VALUES(randomblob(1500));
+      INSERT INTO t2 VALUES(randomblob(1500));
+      DELETE FROM t1 WHERE rowid=1;
+    }
+
+    sql1 {
+      BEGIN UNLOCKED;
+        DELETE FROM t1 WHERE rowid=2;
+    }
+
+    sql2 {
+      DELETE FROM t2;
     }
+
+    sql1 COMMIT
   } {}
 
-  do_test 2.$tn.3 { sql3 { PRAGMA integrity_check } } {ok}
+  do_test 2.$tn.7 { sql3 { PRAGMA integrity_check } } {ok}
 }
 
+reset_db
+do_execsql_test 3.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(x, y);
+  INSERT INTO t1 VALUES(randomblob(1500), randomblob(1500));
+  DELETE FROM t1;
+} {wal}
+
+db close
+sqlite3 db test.db
+breakpoint
+
+do_execsql_test 3.1 {
+  BEGIN UNLOCKED;
+    INSERT INTO t1 VALUES(1, 2);
+  ROLLBACK;
+}
+
+do_execsql_test 3.2 {
+  PRAGMA integrity_check;
+} {ok}
+
+do_execsql_test 3.3 {
+  PRAGMA freelist_count;
+} {2}
+
 finish_test
+