[Bug 43585] New: Calling PageSetupDlgA with invalid default printer leads to an unhandled exception

https://bugs.winehq.org/show_bug.cgi?id=43585

Bug ID: 43585
           Summary: Calling PageSetupDlgA with invalid default printer
                    leads to an unhandled exception
           Product: Wine
           Version: 2.15
          Hardware: x86
                OS: Windows
            Status: UNCONFIRMED
          Severity: minor
          Priority: P2
         Component: comdlg32
          Assignee: [e-mail]
          Reporter: [e-mail]

Created attachment 58997
  --> https://bugs.winehq.org/attachment.cgi?id=58997
possible solution

This was tested in Windows XP with Wine's comdlg32.dll.

Steps to reproduce:
1. set Software\Microsoft\Windows NT\CurrentVersion\Windows\Device to a
non-existent printer
2. run comdlg32 printdlg test

Expected result:
PageSetupDlgA should fail with PDERR_NODEFAULTPRN

Acutal result:
test_PageSetupDlgA crashes after null pointer dereference in
GdiConvertToDevmodeW

Remarks:
If the value of the system default printer stored in Software\Microsoft\Windows
NT\CurrentVersion\Windows\Device gets corrupted or is not properly set upon
printer 
removal, PageSetupDlgA called with the PSD_RETURNDEFAULT flag will cause an
unhandled exception in gdi32:GdiConvertToDevmodeW after calling it with a null
devmode.

At comdlg32:pagesetup_common@3862 get_default_printer will succeed but the
returned printer will be bogus. Then pagesetup_change_printer will fail trying
to get the default driver. When pagesetup_update_papersize is called few lines
below the devmode stored in the pagesetup_data struct passed to it will be
null, which will lead to the crash.

Solution:
Function comdlg32:pagesetup_common needs to check the return value of
comdlg32:pagesetup_change_printer and return if it fails. Attached is a
possible solution to this bug.