From 0e97e9a4c2d3ee1a2deae775546a93b315453a4a Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Thu, 21 Sep 2017 20:43:48 +0000
Subject: [PATCH] In the Windows VFS, when trying to open a database file
 read/write, if it fails check to see if the file exists and is read-only and
 immediately fall back to a read-only open attempt, rather than running the AV
 retry loop.

FossilOrigin-Name: 5d03c738e93d36815248991d9ed3d62297ba1bb966e602e7874410076c144f43
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/os_win.c  | 31 ++++++++++++++++++++++---------
 3 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/manifest b/manifest
index a8b6753d68..2ad1b74bd0 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C In\sthe\sWindows\sVFS,\sdo\snot\semit\san\sSQLITE_CANTOPEN\serror\slog\smessage\swhen\nfalling\sback\sfrom\sSQLITE_OPEN_READWRITE\sto\sSQLITE_OPEN_READONLY.\s\sWait\suntil\nthe\sopen\sfails\scompletely.
-D 2017-09-21T20:03:17.227
+C In\sthe\sWindows\sVFS,\swhen\strying\sto\sopen\sa\sdatabase\sfile\sread/write,\sif\sit\nfails\scheck\sto\ssee\sif\sthe\sfile\sexists\sand\sis\sread-only\sand\simmediately\sfall\nback\sto\sa\sread-only\sopen\sattempt,\srather\sthan\srunning\sthe\sAV\sretry\sloop.
+D 2017-09-21T20:43:48.651
 F Makefile.in 4bc36d913c2e3e2d326d588d72f618ac9788b2fd4b7efda61102611a6495c3ff
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 6033b51b6aea702ea059f6ab2d47b1d3cef648695f787247dd4fb395fe60673f
@@ -443,7 +443,7 @@ F src/os.h 8e976e59eb4ca1c0fca6d35ee803e38951cb0343
 F src/os_common.h b2f4707a603e36811d9b1a13278bffd757857b85
 F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
 F src/os_unix.c 3984fc069df59e26f000e30609611cecdb4e93293e6ee52313a473a7e874af1b
-F src/os_win.c 4c05a0587f38813c18bf3e9427e6be1cdf4763476bccbf335691bda3ea035e03
+F src/os_win.c 5c802f05e706c87c6e4cc6e9527f3364c7a7178458f93dffa5e19ac2e8eef9c1
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c 2aa56a99bb13128d9102e84c7a9f835e546cbb58f0861d481bc3db32973b1628
 F src/pager.h 581698f2177e8bd4008fe4760898ce20b6133d1df22139b9101b5155f900df7a
@@ -1655,7 +1655,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 68e9a840d9cfbf4988e1a68c34e809d15d0235998cf0bfa147a1ab88ea842a61
-R f2ed4d392aa227fcb70e42ba4d74a495
+P fa3f5bcc23d9342f6df8ea15732988d637e9fa5dade85a73b05a9f66136d6964
+R 9677831c8749fca6b9258075623dae5d
 U drh
-Z ed7765808e7b49b8f24c258cf2e29075
+Z d25f7e57106bd66e6a2a3d4c1e5b9c3e
diff --git a/manifest.uuid b/manifest.uuid
index ca469b6368..d08d756e8b 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-fa3f5bcc23d9342f6df8ea15732988d637e9fa5dade85a73b05a9f66136d6964
\ No newline at end of file
+5d03c738e93d36815248991d9ed3d62297ba1bb966e602e7874410076c144f43
\ No newline at end of file
diff --git a/src/os_win.c b/src/os_win.c
index ba8ab0ad34..4c026c5c39 100644
--- a/src/os_win.c
+++ b/src/os_win.c
@@ -4879,6 +4879,14 @@ static int winIsDir(const void *zConverted){
   return (attr!=INVALID_FILE_ATTRIBUTES) && (attr&FILE_ATTRIBUTE_DIRECTORY);
 }
 
+/* forward reference */
+static int winAccess(
+  sqlite3_vfs *pVfs,         /* Not used on win32 */
+  const char *zFilename,     /* Name of file to check */
+  int flags,                 /* Type of test to make on this file */
+  int *pResOut               /* OUT: Result */
+);
+
 /*
 ** Open a file.
 */
@@ -5064,15 +5072,20 @@ static int winOpen(
                /* Noop */
     }
 #else
-    while( (h = osCreateFileW((LPCWSTR)zConverted,
-                              dwDesiredAccess,
-                              dwShareMode, NULL,
-                              dwCreationDisposition,
-                              dwFlagsAndAttributes,
-                              NULL))==INVALID_HANDLE_VALUE &&
-                              winRetryIoerr(&cnt, &lastErrno) ){
-               /* Noop */
-    }
+    do{
+      h = osCreateFileW((LPCWSTR)zConverted,
+                        dwDesiredAccess,
+                        dwShareMode, NULL,
+                        dwCreationDisposition,
+                        dwFlagsAndAttributes,
+                        NULL);
+      if( h!=INVALID_HANDLE_VALUE ) break;
+      if( isReadWrite ){
+        int isRO = 0;
+        int rc2 = winAccess(pVfs, zName, SQLITE_ACCESS_READ, &isRO);
+        if( rc2==SQLITE_OK && isRO ) break;
+      }
+    }while( winRetryIoerr(&cnt, &lastErrno) );
 #endif
   }
 #ifdef SQLITE_WIN32_HAS_ANSI