[Bug 46098] New: ftruncate fails with Invalid Argument when file is memory mapped

https://bugs.winehq.org/show_bug.cgi?id=46098

Bug ID: 46098
           Summary: ftruncate fails with Invalid Argument when file is
                    memory mapped
           Product: Wine
           Version: 3.18
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 62726
  --> https://bugs.winehq.org/attachment.cgi?id=62726
Show how ftruncate fails when file is also memory mapped

When truncating a file with ftruncate() that is still memory mapped, the
ftruncate() fails with -1 and errno is set to 'Invalid argument'.

Truncating the file after the unmap does work.

Expected behavior: the ftruncate also succeeds when the file is still memory
mapped.

I can reproduce this issue under Wine Staging 3.17 and 3.18 (i.e.
wine-3.18-1.fc27.x86_64) under Fedora 27.

Note that truncating before the unmap used to work with older Wine versions. It
also works under Linux and under native Windows.

When I run the wine under strace I don't see any failing truncate syscall.

I've attached a minimal reproducing example. Example output:

Truncate before unmap:

$ wine64 ./test_ftruncate.exe blah
2nd ftruncate before unmap: Invalid argument
$ echo $?
10
$ ls -l blah
... 2342 ...

Truncate the file after unmap:

$ wine64 ./test_ftruncate.exe blah 1
$ echo $?
0
$  ls -l blah
... 23 ...