Windows: Support application fonts as fallbacks

In order to support the generated EUDC.TTE font for
End-User Defined Characters on Windows, we need to allow
fallback fonts which are not part of the default font
collection. This is the same as change
21c7421d4e86b6048f9c2c7a9a81ec4ff1ed278c, but adapted to
the fallback font code path.

Without this change, the EUDC file would still be loaded,
but it would be loaded through the GDI fallback, and we
would display an error message on the console.

Task-number: QTBUG-44594
Change-Id: Id2404228c7fd345523e4e5c99f31862e256930e3
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 17 insertions, 12 deletions

diff --git a/src/platformsupport/fontdatabases/windows/qwindowsfontengine.cpp b/src/platformsupport/fontdatabases/windows/qwindowsfontengine.cpp
index a337332b53..584e4db05d 100644
--- a/src/platformsupport/fontdatabases/windows/qwindowsfontengine.cpp
+++ b/src/platformsupport/fontdatabases/windows/qwindowsfontengine.cpp
@@ -1267,31 +1267,36 @@ QFontEngine *QWindowsMultiFontEngine::loadEngine(int at)
             lf.lfFaceName[nameSubstituteLength] = 0;
         }
 
-        IDWriteFont *directWriteFont = 0;
-        HRESULT hr = data->directWriteGdiInterop->CreateFontFromLOGFONT(&lf, &directWriteFont);
-        if (FAILED(hr)) {
-            qWarning("%s: %s", __FUNCTION__,
-                     qPrintable(msgDirectWriteFunctionFailed(hr, "CreateFontFromLOGFONT", fam, nameSubstitute)));
+        HFONT hfont = CreateFontIndirect(&lf);
+        if (hfont == nullptr) {
+            qErrnoWarning("%s: CreateFontIndirect failed", __FUNCTION__);
         } else {
-            Q_ASSERT(directWriteFont);
-            IDWriteFontFace *directWriteFontFace = NULL;
-            HRESULT hr = directWriteFont->CreateFontFace(&directWriteFontFace);
+            HGDIOBJ oldFont = SelectObject(data->hdc, hfont);
+
+            IDWriteFontFace *directWriteFontFace = nullptr;
+            QWindowsFontEngineDirectWrite *fedw = nullptr;
+            HRESULT hr = data->directWriteGdiInterop->CreateFontFaceFromHdc(data->hdc, &directWriteFontFace);
             if (SUCCEEDED(hr)) {
                 Q_ASSERT(directWriteFontFace);
-                QWindowsFontEngineDirectWrite *fedw = new QWindowsFontEngineDirectWrite(directWriteFontFace,
-                                                                                        fontEngine->fontDef.pixelSize,
-                                                                                        data);
+                fedw = new QWindowsFontEngineDirectWrite(directWriteFontFace,
+                                                         fontEngine->fontDef.pixelSize,
+                                                         data);
                 fedw->fontDef.weight = fontEngine->fontDef.weight;
                 if (fontEngine->fontDef.style > QFont::StyleNormal)
                     fedw->fontDef.style = fontEngine->fontDef.style;
                 fedw->fontDef.family = fam;
                 fedw->fontDef.hintingPreference = fontEngine->fontDef.hintingPreference;
                 fedw->fontDef.stretch = fontEngine->fontDef.stretch;
-                return fedw;
             } else {
                 qWarning("%s: %s", __FUNCTION__,
                          qPrintable(msgDirectWriteFunctionFailed(hr, "CreateFontFace", fam, nameSubstitute)));
             }
+
+            SelectObject(data->hdc, oldFont);
+            DeleteObject(hfont);
+
+            if (fedw != nullptr)
+                return fedw;
         }
     }
 #endif