[Bug 56837] New: Bad file pointer after a file write in appending mode

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56837

Bug ID: 56837
           Summary: Bad file pointer after a file write in appending mode
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: Other

Created attachment 76648
  --> https://bugs.winehq.org/attachment.cgi?id=76648
bug-demo program and its source file

When writing for append into a file, Wine returns a bad ftell() file pointer
unless a fflush() is performed before querying with ftell().

See the bug-demo program (run it under bare metal Windows, then under Wine).

This bug has existed like forever (Wine 6 and newer, for sure).