Windows warnings comparing HANDLE and -1

[Vladislav Vaintroub]

Recently merged XtraDB into MariDB 5.5 brings several new warnings (I checked with VS2012, perhaps it happens elsewhere, too)

37>..\..\..\storage\xtradb\log\log0online.c(547): warning C4047: '=' : 'HANDLE' differs in levels of indirection from 'int'
37>..\..\..\storage\xtradb\log\log0online.c(566): warning C4047: '!=' : 'HANDLE' differs in levels of indirection from 'int'
37>..\..\..\storage\xtradb\log\log0online.c(568): warning C4047: '=' : 'HANDLE' differs in levels of indirection from 'int'
37>..\..\..\storage\xtradb\log\log0online.c(765): warning C4047: '!=' : 'HANDLE' differs in levels of indirection from 'int'
37>..\..\..\storage\xtradb\log\log0online.c(767): warning C4047: '=' : 'HANDLE' differs in levels of indirection from 'int'
37>..\..\..\storage\xtradb\log\log0online.c(1669): warning C4047: '=' : 'HANDLE' differs in levels of indirection from 'int'

Looking at lines in question, those are all places that assign os_file_t value -1 or compare os_file_t with -1. However, on Windows os_file_t is HANDLE and HANDLE is basically void*, so comparison like that is invalid.

INVALID_HANDLE_VALUE sounds like a good candidate instead of -1. Maybe, XtraDB can use macros/inline functions like is_valid() or invalidate() to check or assign file handle values (or anything else that would avoid this type of warning in the future)

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-1977