It is OK for a unix file descriptor to be zero. It just can't be negative.

Adjust an assert accordingly.  Ticket #3781. (CVS 6457)

FossilOrigin-Name: 47aa7eb0e047e30bbf09cb08c1e48c61f8d9861c

manifest

@@ -1,5 +1,5 @@
-C Test\scases\sand\sminor\scode\schanges\sto\sincrease\scoverage\sof\sbtree.c.\s(CVS\s6456)
-D 2009-04-06T17:50:03
+C It\sis\sOK\sfor\sa\sunix\sfile\sdescriptor\sto\sbe\szero.\s\sIt\sjust\scan't\sbe\snegative.\nAdjust\san\sassert\saccordingly.\s\sTicket\s#3781.\s(CVS\s6457)
+D 2009-04-07T00:35:20
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 583e87706abc3026960ed759aff6371faf84c211
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -141,7 +141,7 @@ F src/os.c c2aa4a7d8bb845222e5c37f56cde377b20c3b087
 F src/os.h fa3f4aa0119ff721a2da4b47ffd74406ac864c05
 F src/os_common.h 8c61457df58f1a4bd5f5adc3e90e01b37bf7afbc
 F src/os_os2.c bed77dc26e3a95ce4a204936b9a1ca6fe612fcc5
-F src/os_unix.c 5d667f24615043c937a138faaed5f3e93b8619b0
+F src/os_unix.c e5eef59cfb0f646b5010bc597b7c4a91534efc9b
 F src/os_win.c 524fe4c31c469531191857e8036ef59bfb52d684
 F src/pager.c 1df277b7c78f780df119c9e2ddea6690979489c5
 F src/pager.h 0c9f3520c00d8a3b8e792ca56c9a11b6b02b4b0f
@@ -715,7 +715,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P aea99c572a69a00b709f0de816ea16488d899375
-R 7bc7fd3a531ebb9367938d84424724ab
-U danielk1977
-Z fda09d8876bea1757fca4f0d05a68a01
+P def3a016914f683818b5f013ec4efecbb8fd4c0d
+R dd09bd0133bdadedbd1d713686ab1fb9
+U drh
+Z 8bf6995ce628580cd1999c568866c0af

manifest.uuid

@@ -1 +1 @@
-def3a016914f683818b5f013ec4efecbb8fd4c0d
+47aa7eb0e047e30bbf09cb08c1e48c61f8d9861c

src/os_unix.c

@@ -43,7 +43,7 @@
 **   *  Definitions of sqlite3_vfs objects for all locking methods
 **      plus implementations of sqlite3_os_init() and sqlite3_os_end().
 **
-** $Id: os_unix.c,v 1.248 2009/03/30 07:39:35 danielk1977 Exp $
+** $Id: os_unix.c,v 1.249 2009/04/07 00:35:20 drh Exp $
 */
 #include "sqliteInt.h"
 #if SQLITE_OS_UNIX              /* This file is used on unix only */
@@ -3613,7 +3613,7 @@ static int unixOpen(
   int flags,                   /* Input flags to control the opening */
   int *pOutFlags               /* Output flags returned to SQLite core */
 ){
-  int fd = 0;                    /* File descriptor returned by open() */
+  int fd = -1;                    /* File descriptor returned by open() */
   int dirfd = -1;                /* Directory file descriptor */
   int openFlags = 0;             /* Flags to pass to open() */
   int eType = flags&0xFFFFFF00;  /* Type of file to open */
@@ -3716,7 +3716,7 @@ static int unixOpen(
   }
 #endif
 
-  assert(fd!=0);
+  assert( fd>=0 );
   if( isOpenDirectory ){
     rc = openDirectory(zPath, &dirfd);
     if( rc!=SQLITE_OK ){