[Bug 57575] New: dmsynth: incorrect condition for buffer underrun in synthsink.c:synth_sink_write_data

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=57575

Bug ID: 57575
           Summary: dmsynth: incorrect condition for buffer underrun in
                    synthsink.c:synth_sink_write_data
           Product: Wine
           Version: 9.22
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: dmusic
          Assignee: [e-mail]
          Reporter: [e-mail]
                CC: [e-mail]
      Distribution: ---

Noting this here, so it won't get forgotten.

In synth_sink_write_data there's following condition:

if (current_pos - play_pos <= write_pos - play_pos)

it causes a lot of console spam while current_pos == write_pos.

I though it was perhaps some odd way of preventing integer over/underflow, but
the author of that line, when asked on irc, basically said 'yeah, it's bogus'.

[Bug 57575] dmsynth: incorrect condition for buffer underrun in synthsink.c:synth_sink_write_data

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=57575

Michael Stefaniuc  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
                 CC|                            |[e-mail]
     Ever confirmed|0                           |1
           Keywords|                            |patch

--- Comment #1 from Michael Stefaniuc  ---
Confirming with Street Fighter X Mega Man:
SFxMM_EU.zip SHA1: 396b0d3fc737e7f96d8e7201b3a8ab1fb0e64240

Fixed for me with https://gitlab.winehq.org/wine/wine/-/merge_requests/7940

[Bug 57575] dmsynth: incorrect condition for buffer underrun in synthsink.c:synth_sink_write_data

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=57575

Michael Stefaniuc  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED
      Fixed by SHA1|                            |524e24757be008dbed6946f897d
                   |                            |41b2ef2cb381e

--- Comment #2 from Michael Stefaniuc  ---
Fix merged as 524e24757be008dbed6946f897d41b2ef2cb381e

[Bug 57575] dmsynth: incorrect condition for buffer underrun in synthsink.c:synth_sink_write_data

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=57575

--- Comment #3 from Rafał Mużyło  ---
...so, given the fix, may I ask why exactly play_pos is on both sides of the
comparison ?

[Bug 57575] dmsynth: incorrect condition for buffer underrun in synthsink.c:synth_sink_write_data

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=57575

--- Comment #4 from Michael Stefaniuc  ---
That was my initial impulse too. Removing it produced even wackier ERRs.
Those variables are all DWORDs so unsigned and they rely on unsigned underflow.

[Bug 57575] dmsynth: incorrect condition for buffer underrun in synthsink.c:synth_sink_write_data

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=57575

Alexandre Julliard  changed:

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

--- Comment #5 from Alexandre Julliard  ---
Closing bugs fixed in 10.8.