From 7eb7da8e5205f65165b2ba59d4296a50b1ce0846 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tor=20Arne=20Vestb=C3=B8?= <tor.arne.vestbo@qt.io>
Date: Tue, 27 Jun 2023 18:22:16 +0200
Subject: [PATCH] CoreText: Handle failure to find matching theme font
 descriptors

CTFontDescriptorCreateMatchingFontDescriptors has been observed to
return nullptr, so we need to handle that explicitly.

Fixes: QTBUG-113698
Change-Id: Ic9fa574c14068fcae98fe8e6ceddd8a4f7008210
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 9526a7693604c5513a08a4ab08c0c691c3003f39)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/gui/text/coretext/qcoretextfontdatabase.mm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/gui/text/coretext/qcoretextfontdatabase.mm b/src/gui/text/coretext/qcoretextfontdatabase.mm
index 61c662cd459..7307595bd9b 100644
--- a/src/gui/text/coretext/qcoretextfontdatabase.mm
+++ b/src/gui/text/coretext/qcoretextfontdatabase.mm
@@ -905,7 +905,7 @@ void QCoreTextFontDatabase::populateThemeFonts()
 
             auto addFontVariants = [&](CTFontDescriptorRef descriptor) {
                 QCFType<CFArrayRef> matchingDescriptors = CTFontDescriptorCreateMatchingFontDescriptors(descriptor, nullptr);
-                const int matchingDescriptorsCount = CFArrayGetCount(matchingDescriptors);
+                const int matchingDescriptorsCount = matchingDescriptors ? CFArrayGetCount(matchingDescriptors) : 0;
                 qCDebug(lcQpaFonts) << "Enumerating font variants based on" << id(descriptor)
                     << "resulted in" << matchingDescriptorsCount << "matching descriptors"
                     << matchingDescriptors.as<NSArray*>();