[Bug 37345] New: Wine does not flush stdout if stdout is redirected (Regression!)

https://bugs.winehq.org/show_bug.cgi?id=37345

Bug ID: 37345
           Summary: Wine does not flush stdout if stdout is redirected
                    (Regression!)
           Product: Wine
           Version: 1.7.27
          Hardware: x86
                OS: Linux
            Status: UNCONFIRMED
          Severity: major
          Priority: P2
         Component: msvcrt
          Assignee: [e-mail]
          Reporter: [e-mail]

When calling wine from another process after redirecting stdout to a pipe, wine
does not flush the stdout-buffer correctly anymore. This is a regression.

Attached is a usecase. To test do:
i686-w64-mingw32-gcc helloworld.c
gcc callwine.c
./a.out

What will happen is:
- on a buggy wine it will take 10 seconds and then all of the stdout-buffer is
flushed on the exit of the child. (imagine the child would run longer than the
10 seconds)
- on a good wine we will see some stdout-content then 10 second sleep and then
the rest of the content.

This is a regesstion that happened between 1.7.4 and 1.7.5. The bisect
identified commit afec0b00bd6250fe21e8deccbc8116a4aca6a7a4 "msvcrt: Make the
first call to fwrite buffered." as problem.

The attached patch is a revert of this commit ported forward to 1.7.27.
Unfortunately I don't quite grasp the logics of the offending commit. If
somebody who knows that patch could help, I'd highly appreciate it.

Cheers,
Andreas

P.S. This could be related to bug 32791.

[Bug 37345] Wine does not flush stdout if stdout is redirected (Regression!)

https://bugs.winehq.org/show_bug.cgi?id=37345

Andreas  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |regression, source,
                   |                            |testcase
                 CC|                            |[e-mail]
    Regression SHA1|                            |afec0b00bd6250fe21e8deccbc8
                   |                            |116a4aca6a7a4

[Bug 37345] Wine does not flush stdout if stdout is redirected (Regression!)

https://bugs.winehq.org/show_bug.cgi?id=37345

--- Comment #1 from Andreas  ---
Created attachment 49661
  --> https://bugs.winehq.org/attachment.cgi?id=49661
helloworld.c

The Windows-Side of the TestCase

[Bug 37345] Wine does not flush stdout if stdout is redirected (Regression!)

https://bugs.winehq.org/show_bug.cgi?id=37345

--- Comment #2 from Andreas  ---
Created attachment 49662
  --> https://bugs.winehq.org/attachment.cgi?id=49662
callwine.c

The linux (wrapper) side of the TestCase

[Bug 37345] Wine does not flush stdout if stdout is redirected (Regression!)

https://bugs.winehq.org/show_bug.cgi?id=37345

--- Comment #3 from Andreas  ---
Created attachment 49663
  --> https://bugs.winehq.org/attachment.cgi?id=49663
Revert-msvcrt-Make-the-first-call-to-fwrite-buffered.patch

Revert-patch of the regression-introducing commit.

[Bug 37345] Wine does not flush stdout if stdout is redirected (Regression!)

https://bugs.winehq.org/show_bug.cgi?id=37345

Andreas Fuchs  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #4 from Andreas Fuchs  ---
Redirected (non-pty-stdouts) are supposed to be buffered...

My personal fix is now basically:

callwine.c:
-    int ret = pipe(winestdout);
+    int ret = openpty(&winestdout[0], &winestdout[1], NULL, NULL, NULL);

In case anyone else runs into this at some point...

[Bug 37345] Wine does not flush stdout if stdout is redirected (Regression!)

https://bugs.winehq.org/show_bug.cgi?id=37345

Bruno Jesus  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED

--- Comment #5 from Bruno Jesus  ---
Closing invalid bugs.