Reapply commits [837d82a929] and [c05e7dca17] that were accidentally overwritten.

FossilOrigin-Name: 598de52700ba13e3228289220a74fc62073c62d4

3 files changed, 51 insertions, 7 deletions

diff --git a/manifest b/manifest
index c03e51e25..3855100ef 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sxShmXXX()\smethods\sto\sthe\stest\sVFS\sin\stest_devsym.test.
-D 2010-04-30T16:19:40
+C Reapply\scommits\s[837d82a929]\sand\s[c05e7dca17]\sthat\swere\saccidentally\soverwritten.
+D 2010-04-30T16:24:46
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in d83a0ffef3dcbfb08b410a6c6dd6c009ec9167fb
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -221,7 +221,7 @@ F src/vdbeblob.c 5327132a42a91e8b7acfb60b9d2c3b1c5c863e0e
 F src/vdbemem.c 2a82f455f6ca6f78b59fb312f96054c04ae0ead1
 F src/vdbetrace.c 864cef96919323482ebd9986f2132435115e9cc2
 F src/vtab.c a0f8a40274e4261696ef57aa806de2776ab72cda
-F src/wal.c f08889611d5da7d2cbe9557748e74f70ab454974
+F src/wal.c efe21d703cd5f32c18fd87762b6ac20dc47c5785
 F src/wal.h c3f347ba8f1cde46d9bcc6fedaf3ed0aa4b53294
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
 F src/where.c faadd9c2bf08868e5135192b44e0d753e363a885
@@ -808,7 +808,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P d9250e84ac1fc6590f8670e1d801630650c7846a
-R e706456f30289526a342dac546a83543
+P 1d20342424b452ea96aaf161de1f98f26a9155a0
+R 88f12ad5a621dbb661d799113c2782f7
 U dan
-Z 9513429a159541b5d8980cb57914a083
+Z 72810ce2ab0ab749da9f7335fd238964
diff --git a/manifest.uuid b/manifest.uuid
index 0bfe58ee6..914344034 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-1d20342424b452ea96aaf161de1f98f26a9155a0
\ No newline at end of file
+598de52700ba13e3228289220a74fc62073c62d4
\ No newline at end of file
diff --git a/src/wal.c b/src/wal.c
index 2925023e7..3b57184c8 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -784,8 +784,35 @@ int sqlite3WalClose(
 ){
   int rc = SQLITE_OK;
   if( pWal ){
+    int isDelete = 0;             /* True to unlink wal and wal-index files */
+
+    /* If an EXCLUSIVE lock can be obtained on the database file (using the
+    ** ordinary, rollback-mode locking methods, this guarantees that the
+    ** connection associated with this log file is the only connection to
+    ** the database. In this case checkpoint the database and unlink both
+    ** the wal and wal-index files.
+    **
+    ** The EXCLUSIVE lock is not released before returning.
+    */
+    rc = sqlite3OsLock(pFd, SQLITE_LOCK_EXCLUSIVE);
+    if( rc==SQLITE_OK ){
+      rc = walCheckpoint(pWal, pFd, sync_flags, zBuf);
+      if( rc==SQLITE_OK ){
+        isDelete = 1;
+      }
+      walIndexUnmap(pWal);
+    }
+
     pWal->pVfs->xShmClose(pWal->pWIndex);
     sqlite3OsClose(pWal->pFd);
+    if( isDelete ){
+      int nWal;
+      char *zWal = &((char *)pWal->pFd)[pWal->pVfs->szOsFile];
+      sqlite3OsDelete(pWal->pVfs, zWal, 0);
+      nWal = sqlite3Strlen30(zWal);
+      memcpy(&zWal[nWal], "-index", 7);
+      pWal->pVfs->xShmDelete(pWal->pVfs, zWal);
+    }
     sqlite3_free(pWal);
   }
   return rc;
@@ -1008,6 +1035,23 @@ int sqlite3WalWriteLock(Wal *pWal, int op){
   if( op ){
     assert( pWal->lockState == SQLITE_SHM_READ );
     rc = walSetLock(pWal, SQLITE_SHM_WRITE);
+
+    /* If this connection is not reading the most recent database snapshot,
+    ** it is not possible to write to the database. In this case release
+    ** the write locks and return SQLITE_BUSY.
+    */
+    if( rc==SQLITE_OK ){
+      rc = walIndexMap(pWal, -1);
+      if( rc==SQLITE_OK
+       && memcmp(&pWal->hdr, pWal->pWiData, sizeof(WalIndexHdr))
+      ){
+        rc = SQLITE_BUSY;
+      }
+      walIndexUnmap(pWal);
+      if( rc!=SQLITE_OK ){
+        walSetLock(pWal, SQLITE_SHM_READ);
+      }
+    }
   }else if( pWal->lockState==SQLITE_SHM_WRITE ){
     rc = walSetLock(pWal, SQLITE_SHM_READ);
   }