[Bug 51371] New: Too many fonts slows down kernel32:heap! (caused by gdi32)

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=51371

Bug ID: 51371
           Summary: Too many fonts slows down kernel32:heap! (caused by
                    gdi32)
           Product: Wine
           Version: 6.10
          Hardware: x86-64
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: gdi32
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

In fact having too many fonts slows down the startup of any process that loads
gdi32 (or user32), which is to say essentially every process.

This hits kernel32:heap quite hard because it starts many subprocesses for its
tests. Here's a list of the worst hit tests:

Base  Full set of fonts (see bug 51367)
kernel32:heap          <1s   13s
comctl32:status        <1s   13s
reg.exe:add             3s   17s
regedit.exe:regedit    14s   54s
shell32:shlexec        13s   29s

But it's not just these tests being impacted, it's every one of the 720 test
units, resulting in a full WineTest run taking an extra 9 minutes (on my box,
more on the TestBot's debiant2).

The reason for the slowdown seems similar to the dwrite:font case (bug 51367)
but on the gdi32 side. In particular each process issues quite a lot of these
messages (OPENTYPE_PLATFORM_MAC case iirc) which may or may not be related:

0034:fixme:font:get_name_record_codepage encoding 20 not handled, platform 1.