QSGOpenGLDistanceFieldGlyphCache: fix multiplication result truncation

The type of the expression int * int is int, so truncation has already
happened when the result is assigned to a qint64.

Fix by casting one of the multiplicants to qint64 before performing
the multiplication. This multiplication cannot overflow, because int
is 32-bit on all supported platforms.

The addition of 'size' to the pointer will still truncate the result,
on 32bit platforms, but that check is in itself UB. A follow-up commit
will fix the check, and with it the last truncation to 32bit.

Coverity-Id: 218769
Change-Id: I0d71950695b9743db8c96d825e68bb1e9c47de02
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit cacfc1dbb9719c0ef55cff69dad0921ce1405438)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/quick/scenegraph/qsgrhidistancefieldglyphcache.cpp b/src/quick/scenegraph/qsgrhidistancefieldglyphcache.cpp
index e19649a236..a47b35210b 100644
--- a/src/quick/scenegraph/qsgrhidistancefieldglyphcache.cpp
+++ b/src/quick/scenegraph/qsgrhidistancefieldglyphcache.cpp
@@ -515,7 +515,7 @@ bool QSGRhiDistanceFieldGlyphCache::loadPregeneratedCache(const QRawFont &font)
 
             int width = texInfo->allocatedArea.width();
             int height = texInfo->allocatedArea.height();
-            qint64 size = width * height;
+            qint64 size = qint64(width) * height;
             if (reinterpret_cast<const char *>(textureData + size) > qtdfTableEnd) {
                 qWarning("qtdf table too small in font '%s'.",
                          qPrintable(font.familyName()));