From 5303225aef739c534714c1ac1d4dd096f0cc38d0 Mon Sep 17 00:00:00 2001
From: Friedemann Kleint <Friedemann.Kleint@qt.io>
Date: Tue, 25 Jul 2017 09:52:19 +0200
Subject: Windows font database: Make DirectWrite warnings more verbose

Output family and format error message using _comerror struct.

QWindowsMultiFontEngine::loadEngine: CreateFontFromLOGFONT failed (The operation completed successfully.)
becomes
QWindowsMultiFontEngine::loadEngine: CreateFontFromLOGFONT failed for "8514oem": error 0x88985002 : Indicates the specified font does not exist.

Change-Id: Iccd4622127d94870b4b7465a4b4fdbf34ad1c434
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
---
 .../fontdatabases/windows/qwindowsfontengine.cpp   | 24 ++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

(limited to 'src/platformsupport/fontdatabases')

diff --git a/src/platformsupport/fontdatabases/windows/qwindowsfontengine.cpp b/src/platformsupport/fontdatabases/windows/qwindowsfontengine.cpp
index 6e95fb5a05..1389b497d5 100644
--- a/src/platformsupport/fontdatabases/windows/qwindowsfontengine.cpp
+++ b/src/platformsupport/fontdatabases/windows/qwindowsfontengine.cpp
@@ -56,6 +56,7 @@
 #include <QtCore/QtEndian>
 #include <QtCore/QFile>
 #include <QtCore/qmath.h>
+#include <QtCore/QTextStream>
 #include <QtCore/QThreadStorage>
 #include <QtCore/private/qsystemlibrary_p.h>
 #include <QtCore/private/qstringiterator_p.h>
@@ -66,6 +67,7 @@
 
 #if !defined(QT_NO_DIRECTWRITE)
 #  include <dwrite.h>
+#  include <comdef.h>
 #endif
 
 QT_BEGIN_NAMESPACE
@@ -1228,6 +1230,22 @@ QWindowsMultiFontEngine::QWindowsMultiFontEngine(QFontEngine *fe, int script)
 {
 }
 
+#ifndef QT_NO_DIRECTWRITE
+static QString msgDirectWriteFunctionFailed(HRESULT hr, const char *function,
+                                            const QString &fam, const QString &substitute)
+{
+    _com_error error(hr);
+    QString result;
+    QTextStream str(&result);
+    str << function << " failed for \"" << fam << '"';
+    if (substitute != fam)
+        str << " (substitute: \"" <<  substitute << "\")";
+    str << ": error " << hex << showbase << ulong(hr) << ' ' << noshowbase << dec
+        << ": " << QString::fromWCharArray(error.ErrorMessage());
+    return result;
+}
+#endif // !QT_NO_DIRECTWRITE
+
 QFontEngine *QWindowsMultiFontEngine::loadEngine(int at)
 {
     QFontEngine *fontEngine = engine(0);
@@ -1266,7 +1284,8 @@ QFontEngine *QWindowsMultiFontEngine::loadEngine(int at)
         IDWriteFont *directWriteFont = 0;
         HRESULT hr = data->directWriteGdiInterop->CreateFontFromLOGFONT(&lf, &directWriteFont);
         if (FAILED(hr)) {
-            qErrnoWarning("%s: CreateFontFromLOGFONT failed", __FUNCTION__);
+            qWarning("%s: %s", __FUNCTION__,
+                     qPrintable(msgDirectWriteFunctionFailed(hr, "CreateFontFromLOGFONT", fam, nameSubstitute)));
         } else {
             Q_ASSERT(directWriteFont);
             IDWriteFontFace *directWriteFontFace = NULL;
@@ -1284,7 +1303,8 @@ QFontEngine *QWindowsMultiFontEngine::loadEngine(int at)
                 fedw->fontDef.stretch = fontEngine->fontDef.stretch;
                 return fedw;
             } else {
-                qErrnoWarning("%s: CreateFontFace failed", __FUNCTION__);
+                qWarning("%s: %s", __FUNCTION__,
+                         qPrintable(msgDirectWriteFunctionFailed(hr, "CreateFontFace", fam, nameSubstitute)));
             }
         }
     }
-- 
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