From 951596cdef06e386075280b0dd92cd3fc00764c0 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Tue, 25 Jan 2011 16:20:16 +0000
Subject: [PATCH] Change the name of SQLITE_FCNTL_SYNC to
 SQLITE_FCNTL_SYNC_OMITTED and only send it when PRAGMA synchronous=OFF.  Add
 better documentation to explain what that file-control opcode is used for.

FossilOrigin-Name: 64914980855dbbf19512642836ca962a507b3ddb
---
 manifest        | 26 ++++++++++++++++++--------
 manifest.uuid   |  2 +-
 src/pager.c     | 11 +++++------
 src/sqlite.h.in | 16 ++++++++++------
 4 files changed, 34 insertions(+), 21 deletions(-)

diff --git a/manifest b/manifest
index d63ccb4da2..f168e9a13f 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,8 @@
-C Fix\sa\scouple\sof\stypos\sin\scomments.\sNo\schanges\sto\sactual\scode.
-D 2011-01-25T13:43:35
+-----BEGIN PGP SIGNED MESSAGE-----
+Hash: SHA1
+
+C Change\sthe\sname\sof\sSQLITE_FCNTL_SYNC\sto\sSQLITE_FCNTL_SYNC_OMITTED\sand\sonly\nsend\sit\swhen\sPRAGMA\ssynchronous=OFF.\s\sAdd\sbetter\sdocumentation\sto\sexplain\nwhat\sthat\sfile-control\sopcode\sis\sused\sfor.
+D 2011-01-25T16:20:16.289
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in de6498556d536ae60bb8bb10e8c1ba011448658c
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -162,7 +165,7 @@ F src/os_common.h a8f95b81eca8a1ab8593d23e94f8a35f35d4078f
 F src/os_os2.c 72d0b2e562952a2464308c4ce5f7913ac10bef3e
 F src/os_unix.c aeaf65d261219ad96c021cfd0672509d83c005e4
 F src/os_win.c 2f90f7bdec714fad51cd31b4ecad3cc1b4bb5aad
-F src/pager.c eb355fc87cd84b47f70b479569f1ad1338fb4e2d
+F src/pager.c c8975ac965895d507daa6b3e4e0aca8b4aaf629b
 F src/pager.h 0ea59db2a33bc6c2c02cae34de33367e1effdf76
 F src/parse.y 12b7ebd61ea54f0e1b1083ff69cc2c8ce9353d58
 F src/pcache.c 09d38c44ab275db581f7a2f6ff8b9bc7f8c0faaa
@@ -176,7 +179,7 @@ F src/resolve.c 1c0f32b64f8e3f555fe1f732f9d6f501a7f05706
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c 8a7ba246b0b4bb45df7fbc52681728a0e3deaaa7
 F src/shell.c 83c6f0cc5a79a081c7b9ddfe4f557b47e0bad976
-F src/sqlite.h.in da5f52960e61bd8940413bd07da0e8150531552d
+F src/sqlite.h.in a059e7c0128a656adeb923c34e99a117de99c23d
 F src/sqlite3ext.h c90bd5507099f62043832d73f6425d8d5c5da754
 F src/sqliteInt.h 45926deaf59b1ce3f55d21d5f91a8cecb6a7eb4c
 F src/sqliteLimit.h a17dcd3fb775d63b64a43a55c54cb282f9726f44
@@ -897,7 +900,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 13108ce13c281f31aa60b403567710ae3d925797
-R 65a9c8caa43f6ab5a0a574c1c511a44f
-U dan
-Z e065b48f5c532f6c7bd5d8c0c158d9e1
+P 9167fdb3560b1567a0bdc9a1906a87ec98e161f1
+R 96da40f86ab20bb4a774456ca34a544b
+U drh
+Z c8970634e68cbff2a072ebb3d5e57cae
+-----BEGIN PGP SIGNATURE-----
+Version: GnuPG v1.4.6 (GNU/Linux)
+
+iD8DBQFNPvhDoxKgR168RlERAqjUAJ9akpjzOSwn0PlU/phdYvzW8+YrjQCghpGF
+iTJlh/160LuCnZw69rf6DrI=
+=E72H
+-----END PGP SIGNATURE-----
diff --git a/manifest.uuid b/manifest.uuid
index e9cddf2565..5883969aa6 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-9167fdb3560b1567a0bdc9a1906a87ec98e161f1
\ No newline at end of file
+64914980855dbbf19512642836ca962a507b3ddb
\ No newline at end of file
diff --git a/src/pager.c b/src/pager.c
index a6f7aac370..d2eb3d5e7e 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -5624,15 +5624,14 @@ static int pager_incr_changecounter(Pager *pPager, int isDirectMode){
 */
 int sqlite3PagerSync(Pager *pPager){
   int rc;                              /* Return code */
-  if( pPager->noSync ){
-    rc = SQLITE_OK;
-  }else{
+  if( !pPager->noSync ){
     assert( !MEMDB );
     rc = sqlite3OsSync(pPager->fd, pPager->syncFlags);
-  }
-  if( isOpen(pPager->fd) ){
+  }else if( isOpen(pPager->fd) ){
     assert( !MEMDB );
-    sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SYNC, (void *)&rc);
+    sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SYNC_OMITTED, (void *)&rc);
+  }else{
+    rc = SQLITE_OK;
   }
   return rc;
 }
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 360ccd5779..f3d709213c 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -716,11 +716,15 @@ struct sqlite3_io_methods {
 ** connection.  See the [sqlite3_file_control()] documentation for
 ** additional information.
 **
-** The [SQLITE_FCNTL_SYNC] opcode is used internally. SQLite calls
-** the file-control method with this opcode immediately after the database
-** file is synced, or if the database is running in synchronous=off mode
-** immediately after it would have been synced otherwise. This makes it
-** easier to write special VFS modules that depend on the xSync call.
+** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
+** SQLite and sent to all VFSes in place of a call to the xSync method
+** when the database connection has [PRAGMA synchronous] set to OFF.)^
+** Some specialized VFSes need this signal in order to operate correctly
+** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 
+** VFSes do not need this signal and should silently ignore this opcode.
+** Applications should not call [sqlite3_file_control()] with this
+** opcode as doing so may disrupt the operation of the specilized VFSes
+** that do require it.  
 */
 #define SQLITE_FCNTL_LOCKSTATE        1
 #define SQLITE_GET_LOCKPROXYFILE      2
@@ -729,7 +733,7 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_SIZE_HINT        5
 #define SQLITE_FCNTL_CHUNK_SIZE       6
 #define SQLITE_FCNTL_FILE_POINTER     7
-#define SQLITE_FCNTL_SYNC             8
+#define SQLITE_FCNTL_SYNC_OMITTED     8
 
 
 /*