From a67a905190b85b53c30c9cb800b5e282d9364179 Mon Sep 17 00:00:00 2001 From: Eskil Abrahamsen Blomfeldt Date: Tue, 26 Jan 2016 14:45:46 +0100 Subject: Fix artihmetic exception when using non-scalable fonts For non-scalable fonts, the units_per_EM in FreeType is documented to be undefined and will default to 0, which means that any division by it will cause an exception. The emSquareSize() function already checks if the font is scalable and returns y_ppem if not, so lets use it instead in all locations where we're not already sure the font is scalable. [ChangeLog][Text][Freetype] Fixed a divide-by-zero exception when accessing bitmap fonts. Change-Id: I8839d4c83047fb3f6bb4d69af0258e94a258a4d9 Task-number: QTBUG-45963 Reviewed-by: Konstantin Ritt --- src/gui/text/qfontengine_ft.cpp | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'src/gui/text/qfontengine_ft.cpp') diff --git a/src/gui/text/qfontengine_ft.cpp b/src/gui/text/qfontengine_ft.cpp index 4dd2ee35b1..de5bec6f93 100644 --- a/src/gui/text/qfontengine_ft.cpp +++ b/src/gui/text/qfontengine_ft.cpp @@ -1255,7 +1255,7 @@ QFixed QFontEngineFT::xHeight() const TT_OS2 *os2 = (TT_OS2 *)FT_Get_Sfnt_Table(freetype->face, ft_sfnt_os2); if (os2 && os2->sxHeight) { lockFace(); - QFixed answer = QFixed(os2->sxHeight*freetype->face->size->metrics.y_ppem)/freetype->face->units_per_EM; + QFixed answer = QFixed(os2->sxHeight * freetype->face->size->metrics.y_ppem) / emSquareSize(); unlockFace(); return answer; } @@ -1267,7 +1267,7 @@ QFixed QFontEngineFT::averageCharWidth() const TT_OS2 *os2 = (TT_OS2 *)FT_Get_Sfnt_Table(freetype->face, ft_sfnt_os2); if (os2 && os2->xAvgCharWidth) { lockFace(); - QFixed answer = QFixed(os2->xAvgCharWidth*freetype->face->size->metrics.x_ppem)/freetype->face->units_per_EM; + QFixed answer = QFixed(os2->xAvgCharWidth * freetype->face->size->metrics.x_ppem) / emSquareSize(); unlockFace(); return answer; } @@ -1295,7 +1295,7 @@ void QFontEngineFT::doKerning(QGlyphLayout *g, QFontEngine::ShaperFlags flags) c kerning_pairs_loaded = true; lockFace(); if (freetype->face->size->metrics.x_ppem != 0) { - QFixed scalingFactor(freetype->face->units_per_EM/freetype->face->size->metrics.x_ppem); + QFixed scalingFactor = emSquareSize() / QFixed(freetype->face->size->metrics.x_ppem); unlockFace(); const_cast(this)->loadKerningPairs(scalingFactor); } else { -- cgit v1.2.3