[Bug 55258] New: steam: small window floating on top of all windows even in fullscreen mode

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=55258

Bug ID: 55258
           Summary: steam: small window floating on top of all windows
                    even in fullscreen mode
           Product: Wine
           Version: 8.12
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 74873
  --> https://bugs.winehq.org/attachment.cgi?id=74873
steam_window_bug.png

When running steam with new versions of wine, I'm getting a small square window
which is always on top of all windows, even when I'm playing fullscreen game.

It's usually located around center of screen for me, but during bisecting I
also got a few builds when it appeared at top left corner.

I've tested it with following wine versions:
wine 7.0.2: win7 prefix: good
wine 7.0.2: win10 prefix: does not start
wine 8.0.1: win7 prefix: good
wine 8.0.1: win10 prefix: good
wine 8.9: win10 prefix: bad
wine 8.12: win10 prefix: bad

After that I ran git bisect with following build:
mkdir build32 build64
cd build64
../configure --with-mingw --enable-win64 --prefix=/tmp/wineinstall
cd ../build32
../configure --with-mingw --with-wine64=../build64 --prefix=/tmp/wineinstall
cd ../build64
make $JOBS
cd ../build32
make $JOBS
make $JOBS install
cd ../build64
make $JOBS install

My results are:
2504a2d7bca47fc77bb523114d7b0b6e60213116 is the first bad commit
commit 2504a2d7bca47fc77bb523114d7b0b6e60213116
Author: Rémi Bernon 
Date:   Mon Mar 27 11:58:50 2023 +0200

imm32: Keep the IME UI window on the default input context.

dlls/imm32/imm.c | 61 ++++++++++++++++++++++++++++++++------------------------
 1 file changed, 35 insertions(+), 26 deletions(-)

$ git bisect log
# bad: [9ffeb2622d087a6189ca916553529824791010c3] Release 8.9.
# good: [d8b2687760f7c07eaf481aba2835b820d3092b3e] Release 8.0.1.
git bisect start 'wine-8.9' 'wine-8.0.1'
# skip: [6677c044abb711f423fadfb61f2c9a37da6ff686] Release 8.0.
git bisect skip 6677c044abb711f423fadfb61f2c9a37da6ff686
# good: [7771a9ae79930d112051cfe18b27dec1e5edd245] widl: Simplify attribute
creation with either int or ptr value.
git bisect good 7771a9ae79930d112051cfe18b27dec1e5edd245
# bad: [d1c317720ab6a92811c013408844ffd9e581b2a2] mfreadwrite: Fix an address
of operator typo.
git bisect bad d1c317720ab6a92811c013408844ffd9e581b2a2
# bad: [66bef6db20f72e88a38c4b264e13639015d7817d] msvcrt: Use the sinhf()
implementation from the bundled musl library.
git bisect bad 66bef6db20f72e88a38c4b264e13639015d7817d
# bad: [17fbef91929af9c6ab98e53fb2a54942f0f1a0a5] wmvcore/tests: Don't cast
NULL to another pointer type.
git bisect bad 17fbef91929af9c6ab98e53fb2a54942f0f1a0a5
# skip: [83f0862b43f7b1b7bd23830b4339894c35febea7] wineps: Handle
EMR_SETARCDIRECTION record in spool files.
git bisect skip 83f0862b43f7b1b7bd23830b4339894c35febea7
# good: [6a88500af29b82040f0518eb87171ca047fb95aa] hidparse.sys: Include
zero-count reports in cap count.
git bisect good 6a88500af29b82040f0518eb87171ca047fb95aa
# good: [62ef3c5be1d2c5374399984588a9daa75663d030] taskkill: Factor out
get_task_pid().
git bisect good 62ef3c5be1d2c5374399984588a9daa75663d030
# bad: [956541c9c823fb6048047893545dcee4c108730e] d3d10/effect: Add support for
umin/umax instructions.
git bisect bad 956541c9c823fb6048047893545dcee4c108730e
# good: [4b04d357739f261457316d55b79ecbcff9c0be84] imm32/tests: Add explicit
ImmLoadIME / ImmFreeLayout calls.
git bisect good 4b04d357739f261457316d55b79ecbcff9c0be84
# bad: [2504a2d7bca47fc77bb523114d7b0b6e60213116] imm32: Keep the IME UI window
on the default input context.
git bisect bad 2504a2d7bca47fc77bb523114d7b0b6e60213116
# good: [9117ce4185146a5edd47467d370b3e4dfa588191] imm32/tests: Test
ImmProcessKey with the installed IME.
git bisect good 9117ce4185146a5edd47467d370b3e4dfa588191
# good: [43e22eaa76a443e3053868df1bd8c5d4130a9fde] imm32/tests: Test IME UI
window and IME window presence.
git bisect good 43e22eaa76a443e3053868df1bd8c5d4130a9fde
# good: [0ddad3564f3260f53e5a50b615f6aa6ba27e032b] imm32: Update existing input
contexts on layout change.
git bisect good 0ddad3564f3260f53e5a50b615f6aa6ba27e032b
# first bad commit: [2504a2d7bca47fc77bb523114d7b0b6e60213116] imm32: Keep the
IME UI window on the default input context.

OS: Gentoo Linux Amd64
Kernel: 6.1.38-gentoo
DE: KDE 5.27.5

glxinfo:
OpenGL vendor string: AMD
OpenGL renderer string: AMD Radeon RX 7900 XTX (gfx1100, LLVM 16.0.6, DRM 3.49,
6.1.38-gentoo.65)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 23.1.3
OpenGL core profile shading language version string: 4.60