[SOLVED] Check failed: fallback_available

[digory]

Today I've updated to the latest binary distribution 3.2883.1536.ga8ecb19 Win32. The browser no longer works

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[1201/111525:FATAL:dwrite_font_proxy_init_win.cc(91)] Check failed: fallback_available == base::win::GetVersion() > base::win::VERSION_WIN8 (1 vs. 0)


My machine runs Windows 10. The former build 3.2840.1493.g4e029f4 worked perfectly. Interestingly, the new build's cefclient and cefsimple demo applications work fine. Any ideas why my own application causes the above assertion?

[digory]

Still no clue why the latest build won't run. The offending assertion in dwrite_font_proxy_init_win.cc is:

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/ When IDWriteFontFallback is not available (prior to Win8.1) Skia will
  // still attempt to use DirectWrite to determine fallback fonts (in
  // SkFontMgr_DirectWrite::onMatchFamilyStyleCharacter), which will likely
  // result in trying to load the system font collection. To avoid that and
  // instead fall back on WebKit's fallback logic, we don't use Skia's font
  // fallback if IDWriteFontFallback is not available.
  // This flag can be removed when Win8.0 and earlier are no longer supported.
  bool fallback_available = font_fallback.Get() != nullptr;
  DCHECK_EQ(fallback_available,
    base::win::GetVersion() > base::win::VERSION_WIN8);
  blink::WebFontRendering::setUseSkiaFontFallback(fallback_available);


(Sources from https://chromium.googlesource.com/chromium/src/+/master/content/child/dwrite_font_proxy/dwrite_font_proxy_init_win.cc)

So, assuming base::win::GetVersion determines the version correctly (Window 10), the version will be > VERSION_WIN8, and fallback_available is expected to be true. The check fails, because it isn't. IDWriteFontFallback is a Windows API function https://msdn.microsoft.com/en-us/library/windows/desktop/dn280474(v=vs.85).aspx and should be available since 8.1. The reason why fallback_available might still be false is if font_fallback.Get() is a nullptr. It's initialized in dwrite_font_proxy_init_win.cc like this:

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 if (SUCCEEDED(factory.As(&factory2)) && factory2.Get()) {
    mswr::MakeAndInitialize<FontFallback>(
        &font_fallback, g_font_collection.Get(), sender);
  }


So why might this fail in my case?

[Czarek]

Are you using in your app any unusual Windows API such as DirectWrite or COM components?

[digory]

We're certainly not using DirectWrite. There is some legacy COM functionality compiled into it, but I don't think it is actually used.

[Czarek]

Comment it out and see if that helps.

[digory]

The source code of our application is huge, and I'm not familiar with this part, but I'll try.

[trybaczek]

Hi,
I had the same problem.
Solved it by properly targetting executable for windows 8.1/10 version.
Took manifest file from here: https://msdn.microsoft.com/pl-pl/library/windows/desktop/dn481241(v=vs.85).aspx
and added it to the project.
Hope it helps,
Tristan

[verybigbadboy]

Hey digory,

I have absolutely the same issue as you, did you find any possible reason of this?

[digory]

Comment it out and see if that helps.

I've commented out all I could find that deals with COM/OLE, to no avail.

Hey digory,
I have absolutely the same issue as you, did you find any possible reason of this?

Not yet, I'm still trying to figure it out.

Hi,
I had the same problem.
Solved it by properly targetting executable for windows 8.1/10 version.
Took manifest file from here: https://msdn.microsoft.com/pl-pl/library/windows/desktop/dn481241(v=vs.85).aspx
and added it to the project.

Ah, thanks, I'll check it out.

[verybigbadboy]

Hi Tristan
thats work for me too. thank you.