Make sure the rc variable in OsWrite of os_win.c is always initialized.

Also assert that the amt parameter is always greater than zero.
Ticket #1094. (CVS 2309)

FossilOrigin-Name: 4b399ae7791288e5d44f90da530908d9ca77ff4b

manifest

@@ -1,5 +1,5 @@
-C Fix\sa\scomment\sin\ssqlite3.h.\sNo\scode\schanges.\sTicket\s#1093.\s(CVS\s2308)
-D 2005-02-02T01:13:38
+C Make\ssure\sthe\src\svariable\sin\sOsWrite\sof\sos_win.c\sis\salways\sinitialized.\nAlso\sassert\sthat\sthe\samt\sparameter\sis\salways\sgreater\sthan\szero.\nTicket\s#1094.\s(CVS\s2309)
+D 2005-02-03T00:29:47
 F Makefile.in ffd81f5e926d40b457071b4de8d7c1fa18f39b5a
 F Makefile.linux-gcc a9e5a0d309fa7c38e7c14d3ecf7690879d3a5457
 F README a01693e454a00cc117967e3f9fdab2d4d52e9bc1
@@ -48,9 +48,9 @@ F src/os.h ae44064dc118b20d39450cb331409a775e8bb1c6
 F src/os_common.h 0e7f428ba0a6c40a61bc56c4e96f493231301b73
 F src/os_test.c 91e5f22dd89491e5e1554820e715805f43fa4ece
 F src/os_test.h 6a26a4978492e4bbdbf385554958418ff02db162
-F src/os_unix.c 1f17ceff056c64939e5f2e98bf909fc64d0929ca
+F src/os_unix.c 68d3d32937eee90fe1f50d500d1a4ee826cbe790
 F src/os_unix.h f3097815e041e82e24d92505e1ff61ba24172d13
-F src/os_win.c 3c0b0a3bc33318cf555a1cd130232ad1b9a5a711
+F src/os_win.c bddeae1c3299be0fbe47077dd4e98b786a067f71
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
 F src/pager.c d21565d0e844712809140632062a7b72b768fdff
 F src/pager.h 9eba8c53dd91eae7f3f90743b2ee242da02a9862
@@ -254,12 +254,12 @@ F www/dynload.tcl 02eb8273aa78cfa9070dd4501dca937fb22b466c
 F www/faq.tcl 1e348dec52dc0f21f4216fd6918c69c56daa4cfd
 F www/fileformat.tcl 900c95b9633abc3dcfc384d9ddd8eb4876793059
 F www/formatchng.tcl bfbf14dbf5181e771d06da7797767b0200b36d8a
-F www/index.tcl 2ac775d5247922fd0f5d62178b28d41ccaed7d01
+F www/index.tcl 8cd6d913cccfbd8d46e9b1310fb329fdfbf6053a
 F www/lang.tcl aeb76706558763b3847390a646b3a0ab649c468c
 F www/lockingv3.tcl f59b19d6c8920a931f096699d6faaf61c05db55f
 F www/mingw.tcl d96b451568c5d28545fefe0c80bee3431c73f69c
 F www/nulls.tcl ec35193f92485b87b90a994a01d0171b58823fcf
-F www/oldnews.tcl e8851b24fe424364cd0f3f36b1b4036effea60ef
+F www/oldnews.tcl 5cd036f0c76e4ba3111f153a4ff4c9e5e34b6038
 F www/omitted.tcl 9f332aea97b47ec53234f4cd9aa4b4a6da8641ec
 F www/opcode.tcl dafa030a5a3cc24a2f9fd4cfbfb7d7323d2151b0
 F www/optimizing.tcl f0b2538988d1bbad16cbfe63ec6e8f48c9eb04e5
@@ -272,7 +272,7 @@ F www/tclsqlite.tcl e73f8f8e5f20e8277619433f7970060ab01088fc
 F www/vdbe.tcl 095f106d93875c94b47367384ebc870517431618
 F www/version3.tcl 092a01f5ef430d2c4acc0ae558d74c4bb89638a0
 F www/whentouse.tcl 3e522a06ad41992023c80ca29a048ae2331ca5bd
-P 506088796c846243e24c4cba6be4ce6511fdb345
-R 0ba2e9f3b7d1ba33d703d526a858f307
-U danielk1977
-Z a1ecd87fa80c4e91a7bb3da07993c58a
+P d1ea2fb70be905947c8ff74da8e1f719a8fb85f5
+R c85ccce2907809e515bc05d150167893
+U drh
+Z 76aa18a2185ff42425ab752d44606f71