On Tue, Sep 22, 2009 at 3:06 AM, Ben Klein <shackl...@gmail.com> wrote: > 2009/9/22 Mike Kaplinskiy <mike.kaplins...@gmail.com>: >> On Tue, Sep 22, 2009 at 1:09 AM, Vitaliy Margolen >> <wine-de...@kievinfo.com> wrote: >>>> [/home/cahrendt/wine-git/dlls/wineps.drv/init.c:270]: (error) Possible >>>> null pointer dereference: dmW - otherwise it is redundant to check if >>>> dmW is null at line 272 >>> >>> This is a real bug and should be fixed: >>>> ptrdiff_t off_formname = (const char *)dmW->dmFormName - (const char >>>> *)dmW; >>> Does indeed dereference dmW to get the value of dmFormName. >> >> It actually doesn't, it's a tricky case where dmW->dwFormName == >> &dmW->dwFormName, because dwFormName is an array allocated as part of >> the struct. I made that mistake too the previous cppcheck round. > > I thought I'd covered this before. It's complaining about dmW not > being validated before dmW->dmFormName (which de-references dmW to get > at its dmFormName member). In current code, it's not a problem because > dmW is validated before it's run in both cases (lines 369 and 403). It > is right about the redundant test NULL check on 272 though; if dmW is > NULL, the function will segfault. >
It actually does not dereference anything. Try passing null into the function - it will work just fine. This is a special case because the array isn't dynamically allocated but is part of the struct, which means that dmW->dmFormName == (dmW+__offset of dmFormName) and not *(dmW+__offset of dmFormName). You can try writing a test program yourself - it will run just fine. Mike.
