CORE-17545
Addendum to commit d635ce0c.
- Move the HDC variables initialization via function calls, out of
the variables declaration block.
- Fix warnings (and identical for base/system/userinit/livecd.c):
dll/cpl/sysdm/general.c:72:9: warning: variable 'hLogo' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (hDC == NULL || hDCLogo == NULL || hDCMask == NULL)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
dll/cpl/sysdm/general.c:130:9: note: uninitialized use occurs here
if (hLogo != NULL) DeleteObject(hLogo);
^~~~~
and similar for hMask too:
dll/cpl/sysdm/general.c:129:9: note: uninitialized use occurs here
if (hMask != NULL) DeleteObject(hMask);
^~~~~
## Purpose
[SYSDM]
- When closing System Properties page, log show
(win32ss/user/ntuser/windc.c:749) err: [00060138] GetDC() without ReleaseDC()!
because GetDC() is called (multiple times) without properly calling ReleaseDC() as required in order to release a device context.
- This module also lacks some error management in case null DC are provided (on error).
- LiveCD Userinit, based on SYSDM is affected too.
[DESK]
- Fix missing ReleaseDC related to the spectrum (color depth)
## Proposed changes
- ReleaseDC() added.
- Error management in case of null DC.
- Overall alignement of LiveCD Userinit and SYSDM.
