Line spacing fixes

QTextEdit (via QTextLayout) and QPlainTextEdit in Qt used to ignore
any font leading but added one extra pixel in QFontMetrics. With many
freetype fonts,  this resulted in a "spacy" text layout.

The necessary fixes on X11 and Windows were to take (positive) leading
into account, to make the font database convert point sizes to pixel
sizes without rounding to plain integer values, and to subtract the
extra pixel from QFontMetrics from the font engines' descent value.

The change also fixes several places in styles and widgets, where
QFontMetrics::lineSpacing() was wrongly used instead of
QFontMetrics::height().

Ideally we should also handle negative leading, which would require
additional and bigger code changes in QTextLayout and QPlainTextEdit.
In addition, all other editors we have tested seem to ignore leading on
X11. If we choose to believe the values provided by freetype, our text
layout would be one pixel smaller than everybody else's.

On the Mac, this change does nothing. There our layout is still too spacy,
and for smaller fonts quite ugly compared to native Mac applications.

Done with mae.

Reviewed-by: mae

27 files changed, 149 insertions, 65 deletions

diff --git a/src/gui/embedded/qdecorationdefault_qws.cpp b/src/gui/embedded/qdecorationdefault_qws.cpp
index 5bc8826..70389d3 100644
--- a/src/gui/embedded/qdecorationdefault_qws.cpp
+++ b/src/gui/embedded/qdecorationdefault_qws.cpp
@@ -394,7 +394,7 @@ QPixmap QDecorationDefault::pixmapFor(const QWidget *widget,
 */
 int QDecorationDefault::titleBarHeight(const QWidget *)
 {
-    return qMax(20, QApplication::fontMetrics().lineSpacing() + BORDER_WIDTH);
+    return qMax(20, QApplication::fontMetrics().height() + BORDER_WIDTH);
 }
 
 /*!
diff --git a/src/gui/embedded/qdecorationwindows_qws.cpp b/src/gui/embedded/qdecorationwindows_qws.cpp
index 77393cf..7764ca5 100644
--- a/src/gui/embedded/qdecorationwindows_qws.cpp
+++ b/src/gui/embedded/qdecorationwindows_qws.cpp
@@ -216,7 +216,7 @@ QRegion QDecorationWindows::region(const QWidget *widget, const QRect &rect, int
     bool hasMinimize = flags & Qt::WindowMinimizeButtonHint;
     bool hasMaximize = flags & Qt::WindowMaximizeButtonHint;
     const QFontMetrics fontMetrics = QApplication::fontMetrics();
-    int titleHeight = hasTitle ? qMax(20, fontMetrics.lineSpacing()) : 0;
+    int titleHeight = hasTitle ? qMax(20, fontMetrics.height()) : 0;
     int state = widget->windowState();
     bool isMinimized = state & Qt::WindowMinimized;
     bool isMaximized = state & Qt::WindowMaximized;
diff --git a/src/gui/itemviews/qheaderview.cpp b/src/gui/itemviews/qheaderview.cpp
index fc9820f..3bd9a19 100644
--- a/src/gui/itemviews/qheaderview.cpp
+++ b/src/gui/itemviews/qheaderview.cpp
@@ -1419,7 +1419,7 @@ int QHeaderView::minimumSectionSize() const
         int margin = style()->pixelMetric(QStyle::PM_HeaderMargin, 0, this);
         if (d->orientation == Qt::Horizontal)
             return qMax(strut.width(), (fontMetrics().maxWidth() + margin));
-        return qMax(strut.height(), (fontMetrics().lineSpacing() + margin));
+        return qMax(strut.height(), (fontMetrics().height() + margin));
     }
     return d->minimumSectionSize;
 }
diff --git a/src/gui/styles/qcleanlooksstyle.cpp b/src/gui/styles/qcleanlooksstyle.cpp
index fabd7ca..fc12cfe 100644
--- a/src/gui/styles/qcleanlooksstyle.cpp
+++ b/src/gui/styles/qcleanlooksstyle.cpp
@@ -3866,7 +3866,7 @@ QSize QCleanlooksStyle::sizeFromContents(ContentsType type, const QStyleOption *
         if (const QStyleOptionMenuItem *menuItem = qstyleoption_cast<const QStyleOptionMenuItem *>(option)) {
             if (menuItem->menuItemType == QStyleOptionMenuItem::Separator) {
                 if (!menuItem->text.isEmpty()) {
-                    newSize.setHeight(menuItem->fontMetrics.lineSpacing());
+                    newSize.setHeight(menuItem->fontMetrics.height());
                 }
             }
 #ifndef QT_NO_COMBOBOX
diff --git a/src/gui/styles/qcommonstyle.cpp b/src/gui/styles/qcommonstyle.cpp
index 5886512..70d130a 100644
--- a/src/gui/styles/qcommonstyle.cpp
+++ b/src/gui/styles/qcommonstyle.cpp
@@ -4396,13 +4396,13 @@ int QCommonStyle::pixelMetric(PixelMetric m, const QStyleOption *opt, const QWid
     case PM_TitleBarHeight: {
         if (const QStyleOptionTitleBar *tb = qstyleoption_cast<const QStyleOptionTitleBar *>(opt)) {
             if ((tb->titleBarFlags & Qt::WindowType_Mask) == Qt::Tool) {
-                ret = qMax(widget ? widget->fontMetrics().lineSpacing() : opt->fontMetrics.lineSpacing(), 16);
+                ret = qMax(widget ? widget->fontMetrics().height() : opt->fontMetrics.height(), 16);
 #ifndef QT_NO_DOCKWIDGET
             } else if (qobject_cast<const QDockWidget*>(widget)) {
-                ret = qMax(widget->fontMetrics().lineSpacing(), int(QStyleHelper::dpiScaled(13)));
+                ret = qMax(widget->fontMetrics().height(), int(QStyleHelper::dpiScaled(13)));
 #endif
             } else {
-                ret = qMax(widget ? widget->fontMetrics().lineSpacing() : opt->fontMetrics.lineSpacing(), 18);
+                ret = qMax(widget ? widget->fontMetrics().height() : opt->fontMetrics.height(), 18);
             }
         } else {
             ret = int(QStyleHelper::dpiScaled(18.));
diff --git a/src/gui/styles/qmotifstyle.cpp b/src/gui/styles/qmotifstyle.cpp
index e6c60cf..b65d45c 100644
--- a/src/gui/styles/qmotifstyle.cpp
+++ b/src/gui/styles/qmotifstyle.cpp
@@ -1154,7 +1154,7 @@ void QMotifStyle::drawControl(ControlElement element, const QStyleOption *opt, Q
                                  menuitem->palette, menuitem->state & State_Enabled, menuitem->text,
                                  QPalette::Text);
                     textWidth = menuitem->fontMetrics.width(menuitem->text) + 10;
-                    y += menuitem->fontMetrics.lineSpacing() / 2;
+                    y += menuitem->fontMetrics.height() / 2;
                     p->setFont(oldFont);
                 }
                 p->setPen(opt->palette.dark().color());
@@ -2056,7 +2056,7 @@ QMotifStyle::sizeFromContents(ContentsType ct, const QStyleOption *opt,
 
             if (mi->menuItemType == QStyleOptionMenuItem::Separator) {
                 w = 10;
-                h = (mi->text.isEmpty()) ? motifSepHeight : mi->fontMetrics.lineSpacing();
+                h = (mi->text.isEmpty()) ? motifSepHeight : mi->fontMetrics.height();
             }
 
             // a little bit of border can never harm
diff --git a/src/gui/styles/qplastiquestyle.cpp b/src/gui/styles/qplastiquestyle.cpp
index ce2109a..09f5d36 100644
--- a/src/gui/styles/qplastiquestyle.cpp
+++ b/src/gui/styles/qplastiquestyle.cpp
@@ -5027,7 +5027,7 @@ QSize QPlastiqueStyle::sizeFromContents(ContentsType type, const QStyleOption *o
     case CT_MenuItem:
         if (const QStyleOptionMenuItem *menuItem = qstyleoption_cast<const QStyleOptionMenuItem *>(option)) {
             if (menuItem->menuItemType == QStyleOptionMenuItem::Separator)
-                newSize.setHeight(menuItem->text.isEmpty() ? 2 : menuItem->fontMetrics.lineSpacing());
+                newSize.setHeight(menuItem->text.isEmpty() ? 2 : menuItem->fontMetrics.height());
         }
         break;
     case CT_MenuBarItem:
@@ -5607,11 +5607,11 @@ int QPlastiqueStyle::pixelMetric(PixelMetric metric, const QStyleOption *option,
 #ifdef QT3_SUPPORT
         if (widget && widget->inherits("Q3DockWindowTitleBar")) {
             // Q3DockWindow has smaller title bars than QDockWidget
-            ret = qMax(widget->fontMetrics().lineSpacing(), 20);
+            ret = qMax(widget->fontMetrics().height(), 20);
         } else
 #endif
-        ret = qMax(widget ? widget->fontMetrics().lineSpacing() :
-                   (option ? option->fontMetrics.lineSpacing() : 0), 30);
+        ret = qMax(widget ? widget->fontMetrics().height() :
+                   (option ? option->fontMetrics.height() : 0), 30);
         break;
     case PM_MaximumDragDistance:
         return -1;
diff --git a/src/gui/styles/qstylesheetstyle.cpp b/src/gui/styles/qstylesheetstyle.cpp
index 707b05e..2d90aa1 100644
--- a/src/gui/styles/qstylesheetstyle.cpp
+++ b/src/gui/styles/qstylesheetstyle.cpp
@@ -4722,7 +4722,7 @@ int QStyleSheetStyle::pixelMetric(PixelMetric m, const QStyleOption *opt, const
             return subRule.size().height();
         else if (subRule.hasBox() || subRule.hasBorder()) {
             QFontMetrics fm = opt ?  opt->fontMetrics : w->fontMetrics();
-            return subRule.size(QSize(0, fm.lineSpacing())).height();
+            return subRule.size(QSize(0, fm.height())).height();
         }
         break;
                             }
diff --git a/src/gui/text/qfont.cpp b/src/gui/text/qfont.cpp
index 1285935..1b4c380 100644
--- a/src/gui/text/qfont.cpp
+++ b/src/gui/text/qfont.cpp
@@ -2632,7 +2632,7 @@ QFontCache::~QFontCache()
     while (it != end) {
         if (--it.value().data->cache_count == 0) {
             if (it.value().data->ref == 0) {
-                FC_DEBUG("QFontCache::~QFontCache: deleting engine %p key=(%d / %g %d %d %d %d)",
+                FC_DEBUG("QFontCache::~QFontCache: deleting engine %p key=(%d / %g %g %d %d %d)",
                          it.value().data, it.key().script, it.key().def.pointSize,
                          it.key().def.pixelSize, it.key().def.weight, it.key().def.style,
                          it.key().def.fixedPitch);
diff --git a/src/gui/text/qfont_p.h b/src/gui/text/qfont_p.h
index d74f0b4..144a82d 100644
--- a/src/gui/text/qfont_p.h
+++ b/src/gui/text/qfont_p.h
@@ -86,7 +86,7 @@ struct QFontDef
 #endif // Q_WS_X11
 
     qreal pointSize;
-    int pixelSize;
+    qreal pixelSize;
 
     uint styleStrategy : 16;
     uint styleHint     : 8;
diff --git a/src/gui/text/qfontdatabase.cpp b/src/gui/text/qfontdatabase.cpp
index 738e36a..fb8444e 100644
--- a/src/gui/text/qfontdatabase.cpp
+++ b/src/gui/text/qfontdatabase.cpp
@@ -1331,7 +1331,7 @@ static void match(int script, const QFontDef &request,
              "    family: %s [%s], script: %d\n"
              "    weight: %d, style: %d\n"
              "    stretch: %d\n"
-             "    pixelSize: %d\n"
+             "    pixelSize: %g\n"
              "    pitch: %c",
              family_name.isEmpty() ? "-- first in script --" : family_name.toLatin1().constData(),
              foundry_name.isEmpty() ? "-- any --" : foundry_name.toLatin1().constData(),
diff --git a/src/gui/text/qfontdatabase_win.cpp b/src/gui/text/qfontdatabase_win.cpp
index ae26dab..6cde9ed 100644
--- a/src/gui/text/qfontdatabase_win.cpp
+++ b/src/gui/text/qfontdatabase_win.cpp
@@ -40,6 +40,7 @@
 ****************************************************************************/
 
 #include "qt_windows.h"
+#include <qmath.h>
 #include <private/qapplication_p.h>
 #include "qfont_p.h"
 #include "qfontengine_p.h"
@@ -670,7 +671,7 @@ QFontEngine *loadEngine(int script, const QFontPrivate *fp, const QFontDef &requ
                 break;
         }
 
-        lf.lfHeight = -request.pixelSize;
+        lf.lfHeight = -qRound(request.pixelSize);
         lf.lfWidth                = 0;
         lf.lfEscapement        = 0;
         lf.lfOrientation        = 0;
@@ -899,7 +900,6 @@ static QFontEngine *loadWin(const QFontPrivate *d, int script, const QFontDef &r
     return fe;
 }
 
-
 void QFontDatabase::load(const QFontPrivate *d, int script)
 {
     // sanity checks
@@ -910,8 +910,9 @@ void QFontDatabase::load(const QFontPrivate *d, int script)
     // normalize the request to get better caching
     QFontDef req = d->request;
     if (req.pixelSize <= 0)
-        req.pixelSize = qMax(1, qRound(req.pointSize * d->dpi / 72.));
-    req.pointSize = 0;
+        req.pixelSize = qreal((req.pointSize * d->dpi) / 72.);
+    if (req.pixelSize < 1)
+        req.pixelSize = 1;
     if (req.weight == 0)
         req.weight = QFont::Normal;
     if (req.stretch == 0)
@@ -928,7 +929,8 @@ void QFontDatabase::load(const QFontPrivate *d, int script)
     QFontEngine *fe = QFontCache::instance()->findEngine(key);
 
     // set it to the actual pointsize, so QFontInfo will do the right thing
-    req.pointSize = req.pixelSize*72./d->dpi;
+    if (req.pointSize < 0)
+        req.pointSize = req.pixelSize*72./d->dpi;
 
     if (!fe) {
         if (qt_enable_test_font && req.family == QLatin1String("__Qt__Box__Engine__")) {
diff --git a/src/gui/text/qfontdatabase_x11.cpp b/src/gui/text/qfontdatabase_x11.cpp
index 27ff003..b582e4a 100644
--- a/src/gui/text/qfontdatabase_x11.cpp
+++ b/src/gui/text/qfontdatabase_x11.cpp
@@ -51,6 +51,7 @@
 #include <qfile.h>
 #include <qtemporaryfile.h>
 #include <qabstractfileengine.h>
+#include <qmath.h>
 
 #include <ctype.h>
 #include <stdlib.h>
@@ -757,7 +758,7 @@ QFontDef qt_FcPatternToQFontDef(FcPattern *pattern, const QFontDef &request)
 
     double size;
     if (FcPatternGetDouble(pattern, FC_PIXEL_SIZE, 0, &size) == FcResultMatch)
-        fontDef.pixelSize = qRound(size);
+        fontDef.pixelSize = size;
     else
         fontDef.pixelSize = 12;
 
@@ -1455,7 +1456,7 @@ void qt_addPatternProps(FcPattern *pattern, int screen, int script, const QFontD
         slant_value = FC_SLANT_OBLIQUE;
     FcPatternAddInteger(pattern, FC_SLANT, slant_value);
 
-    double size_value = qMax(1, request.pixelSize);
+    double size_value = qMax(1., request.pixelSize);
     FcPatternAddDouble(pattern, FC_PIXEL_SIZE, size_value);
 
     int stretch = request.stretch;
@@ -1893,8 +1894,9 @@ void QFontDatabase::load(const QFontPrivate *d, int script)
     // normalize the request to get better caching
     QFontDef req = d->request;
     if (req.pixelSize <= 0)
-        req.pixelSize = qRound(qt_pixelSize(req.pointSize, d->dpi));
-    req.pointSize = 0;
+        req.pixelSize = floor(qt_pixelSize(req.pointSize, d->dpi) * 100 + 0.5) / 100;
+    if (req.pixelSize < 1)
+        req.pixelSize = 1;
     if (req.weight == 0)
         req.weight = QFont::Normal;
     if (req.stretch == 0)
@@ -1909,7 +1911,9 @@ void QFontDatabase::load(const QFontPrivate *d, int script)
         return;
 
     // set it to the actual pointsize, so QFontInfo will do the right thing
-    req.pointSize = qt_pointSize(req.pixelSize, d->dpi);
+    if (req.pointSize < 0)
+        req.pointSize = qt_pointSize(req.pixelSize, d->dpi);
+
 
     QFontEngine *fe = QFontCache::instance()->findEngine(key);
 
diff --git a/src/gui/text/qfontengine_ft.cpp b/src/gui/text/qfontengine_ft.cpp
index 3da1593..4041717 100644
--- a/src/gui/text/qfontengine_ft.cpp
+++ b/src/gui/text/qfontengine_ft.cpp
@@ -327,7 +327,7 @@ void QFreetypeFace::release(const QFontEngine::FaceId &face_id)
 
 void QFreetypeFace::computeSize(const QFontDef &fontDef, int *xsize, int *ysize, bool *outline_drawing)
 {
-    *ysize = fontDef.pixelSize << 6;
+    *ysize = qRound(fontDef.pixelSize * 64);
     *xsize = *ysize * fontDef.stretch / 100;
     *outline_drawing = false;
 
@@ -387,7 +387,9 @@ QFontEngine::Properties QFreetypeFace::properties() const
         p.descent = QFixed::fromFixed(-face->size->metrics.descender);
         p.leading = QFixed::fromFixed(face->size->metrics.height - face->size->metrics.ascender + face->size->metrics.descender);
         p.emSquare = face->size->metrics.y_ppem;
-        p.boundingBox = QRectF(-p.ascent.toReal(), 0, (p.ascent + p.descent).toReal(), face->size->metrics.max_advance/64.);
+//        p.boundingBox = QRectF(-p.ascent.toReal(), 0, (p.ascent + p.descent).toReal(), face->size->metrics.max_advance/64.);
+        p.boundingBox = QRectF(0, -p.ascent.toReal(),
+                               face->size->metrics.max_advance/64, (p.ascent + p.descent).toReal() );
     }
     p.italicAngle = 0;
     p.capHeight = p.ascent;
@@ -709,6 +711,7 @@ bool QFontEngineFT::init(FaceId faceId, bool antialias, GlyphFormat format)
     hbFace = freetype->hbFace;
 
     metrics = face->size->metrics;
+
 #if defined(Q_WS_QWS)
     /*
        TrueType fonts with embedded bitmaps may have a bitmap font specific
@@ -1219,7 +1222,8 @@ QFixed QFontEngineFT::ascent() const
 
 QFixed QFontEngineFT::descent() const
 {
-    return QFixed::fromFixed(-metrics.descender);
+    // subtract a pixel to work around QFontMetrics's built-in + 1
+    return QFixed::fromFixed(-metrics.descender - 64);
 }
 
 QFixed QFontEngineFT::leading() const
diff --git a/src/gui/text/qfontengine_win.cpp b/src/gui/text/qfontengine_win.cpp
index d781c70..fd34d0f 100644
--- a/src/gui/text/qfontengine_win.cpp
+++ b/src/gui/text/qfontengine_win.cpp
@@ -577,7 +577,9 @@ QFixed QFontEngineWin::ascent() const
 
 QFixed QFontEngineWin::descent() const
 {
-    return tm.tmDescent;
+    // ### we substract 1 to even out the historical +1 in QFontMetrics's
+    // ### height=asc+desc+1 equation. Fix in Qt5.
+    return tm.tmDescent - 1;
 }
 
 QFixed QFontEngineWin::leading() const
diff --git a/src/gui/text/qtextdocumentlayout.cpp b/src/gui/text/qtextdocumentlayout.cpp
index de83d39..73434b1 100644
--- a/src/gui/text/qtextdocumentlayout.cpp
+++ b/src/gui/text/qtextdocumentlayout.cpp
@@ -1437,7 +1437,9 @@ void QTextDocumentLayoutPrivate::drawListItem(const QPointF &offset, QPainter *p
         option.setTextDirection(dir);
         layout.setTextOption(option);
         layout.beginLayout();
-        layout.createLine();
+        QTextLine line = layout.createLine();
+        if (line.isValid())
+            line.setLeadingIncluded(true);
         layout.endLayout();
         layout.draw(painter, QPointF(r.left(), pos.y()));
         break;
@@ -2579,6 +2581,7 @@ void QTextDocumentLayoutPrivate::layoutBlock(const QTextBlock &bl, int blockPosi
             QTextLine line = tl->createLine();
             if (!line.isValid())
                 break;
+            line.setLeadingIncluded(true);
 
             QFixed left, right;
             floatMargins(layoutStruct->y, layoutStruct, &left, &right);
diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index 81c9142..a91408f 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -1042,7 +1042,7 @@ void QTextEngine::shapeTextWithCE(int item) const
     QScriptItem &si = layoutData->items[item];
     si.glyph_data_offset = layoutData->used;
 
-    QFontEngine *fe = fontEngine(si, &si.ascent, &si.descent);
+    QFontEngine *fe = fontEngine(si, &si.ascent, &si.descent, &si.leading);
 
     QTextEngine::ShaperFlags flags;
     if (si.analysis.bidiLevel % 2)
@@ -1119,7 +1119,7 @@ void QTextEngine::shapeTextWithHarfbuzz(int item) const
 
     si.glyph_data_offset = layoutData->used;
 
-    QFontEngine *font = fontEngine(si, &si.ascent, &si.descent);
+    QFontEngine *font = fontEngine(si, &si.ascent, &si.descent, &si.leading);
 
     bool kerningEnabled = this->font(si).d->kerning;
 
@@ -1350,8 +1350,11 @@ void QTextEngine::shape(int item) const
                                             layoutData->items[item].position + block.position(), format);
         }
     } else if (layoutData->items[item].analysis.flags == QScriptAnalysis::Tab) {
-        // set up at least the ascent/descent of the script item for the tab
-        fontEngine(layoutData->items[item], &layoutData->items[item].ascent, &layoutData->items[item].descent);
+        // set up at least the ascent/descent/leading of the script item for the tab
+        fontEngine(layoutData->items[item],
+                   &layoutData->items[item].ascent,
+                   &layoutData->items[item].descent,
+                   &layoutData->items[item].leading);
     } else {
         shapeText(item);
     }
@@ -1737,7 +1740,7 @@ QFont QTextEngine::font(const QScriptItem &si) const
     return font;
 }
 
-QFontEngine *QTextEngine::fontEngine(const QScriptItem &si, QFixed *ascent, QFixed *descent) const
+QFontEngine *QTextEngine::fontEngine(const QScriptItem &si, QFixed *ascent, QFixed *descent, QFixed *leading) const
 {
     QFontEngine *engine = 0;
     QFontEngine *scaledEngine = 0;
@@ -1777,6 +1780,7 @@ QFontEngine *QTextEngine::fontEngine(const QScriptItem &si, QFixed *ascent, QFix
     if (ascent) {
         *ascent = engine->ascent();
         *descent = engine->descent();
+        *leading = engine->leading();
     }
 
     if (scaledEngine)
@@ -2009,8 +2013,12 @@ void QScriptLine::setDefaultHeight(QTextEngine *eng)
         e = eng->fnt.d->engineForScript(QUnicodeTables::Common);
     }
 
-    ascent = qMax(ascent, e->ascent());
-    descent = qMax(descent, e->descent());
+    QFixed other_ascent = e->ascent();
+    QFixed other_descent = e->descent();
+    QFixed other_leading = e->leading();
+    leading = qMax(leading + ascent, other_leading + other_ascent) - qMax(ascent, other_ascent);
+    ascent = qMax(ascent, other_ascent);
+    descent = qMax(descent, other_descent);
 }
 
 QTextEngine::LayoutData::LayoutData()
diff --git a/src/gui/text/qtextengine_mac.cpp b/src/gui/text/qtextengine_mac.cpp
index e101830..eeccc72 100644
--- a/src/gui/text/qtextengine_mac.cpp
+++ b/src/gui/text/qtextengine_mac.cpp
@@ -557,7 +557,7 @@ void QTextEngine::shapeTextMac(int item) const
 
     si.glyph_data_offset = layoutData->used;
 
-    QFontEngine *font = fontEngine(si, &si.ascent, &si.descent);
+    QFontEngine *font = fontEngine(si, &si.ascent, &si.descent, &si.leading);
     if (font->type() != QFontEngine::Multi) {
         shapeTextWithHarfbuzz(item);
         return;
diff --git a/src/gui/text/qtextengine_p.h b/src/gui/text/qtextengine_p.h
index 85c6928..a1d363b 100644
--- a/src/gui/text/qtextengine_p.h
+++ b/src/gui/text/qtextengine_p.h
@@ -345,11 +345,11 @@ struct Q_AUTOTEST_EXPORT QScriptItem
 {
     inline QScriptItem()
         : position(0),
-          num_glyphs(0), descent(-1), ascent(-1), width(-1),
+          num_glyphs(0), descent(-1), ascent(-1), leading(-1), width(-1),
           glyph_data_offset(0) {}
     inline QScriptItem(int p, const QScriptAnalysis &a)
         : position(p), analysis(a),
-          num_glyphs(0), descent(-1), ascent(-1), width(-1),
+          num_glyphs(0), descent(-1), ascent(-1), leading(-1), width(-1),
           glyph_data_offset(0) {}
 
     int position;
@@ -357,6 +357,7 @@ struct Q_AUTOTEST_EXPORT QScriptItem
     unsigned short num_glyphs;
     QFixed descent;
     QFixed ascent;
+    QFixed leading;
     QFixed width;
     int glyph_data_offset;
     QFixed height() const { return ascent + descent + 1; }
@@ -373,9 +374,10 @@ struct Q_AUTOTEST_EXPORT QScriptLine
     QScriptLine()
         : from(0), length(0),
         justified(0), gridfitted(0),
-        hasTrailingSpaces(0) {}
+        hasTrailingSpaces(0), leadingIncluded(0) {}
     QFixed descent;
     QFixed ascent;
+    QFixed leading;
     QFixed x;
     QFixed y;
     QFixed width;
@@ -385,7 +387,11 @@ struct Q_AUTOTEST_EXPORT QScriptLine
     mutable uint justified : 1;
     mutable uint gridfitted : 1;
     uint hasTrailingSpaces : 1;
-    QFixed height() const { return ascent + descent + 1; }
+    uint leadingIncluded : 1;
+    QFixed height() const { return ascent + descent + 1
+                            + (leadingIncluded?  qMax(QFixed(),leading) : QFixed()); }
+    QFixed base() const { return ascent
+                          + (leadingIncluded ? qMax(QFixed(),leading) : QFixed()); }
     void setDefaultHeight(QTextEngine *eng);
     void operator+=(const QScriptLine &other);
 };
@@ -394,6 +400,7 @@ Q_DECLARE_TYPEINFO(QScriptLine, Q_PRIMITIVE_TYPE);
 
 inline void QScriptLine::operator+=(const QScriptLine &other)
 {
+    leading= qMax(leading + ascent, other.leading + other.ascent) - qMax(ascent, other.ascent);
     descent = qMax(descent, other.descent);
     ascent = qMax(ascent, other.ascent);
     textWidth += other.textWidth;
@@ -476,7 +483,7 @@ public:
         return end - si->position;
     }
 
-    QFontEngine *fontEngine(const QScriptItem &si, QFixed *ascent = 0, QFixed *descent = 0) const;
+    QFontEngine *fontEngine(const QScriptItem &si, QFixed *ascent = 0, QFixed *descent = 0, QFixed *leading = 0) const;
     QFont font(const QScriptItem &si) const;
     inline QFont font() const { return fnt; }
 
diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index c5f0e35..4600a29 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -860,7 +860,7 @@ QRectF QTextLayout::boundingRect() const
         ymin = qMin(ymin, si.y);
         xmax = qMax(xmax, si.x+qMax(si.width, si.textWidth));
         // ### shouldn't the ascent be used in ymin???
-        ymax = qMax(ymax, si.y+si.ascent+si.descent+1);
+        ymax = qMax(ymax, si.y+si.height());
     }
     return QRectF(xmin.toReal(), ymin.toReal(), (xmax-xmin).toReal(), (ymax-ymin).toReal());
 }
@@ -1071,10 +1071,10 @@ static void addSelectedRegionsToPath(QTextEngine *eng, int lineNumber, const QPo
 
     QTextLineItemIterator iterator(eng, lineNumber, pos, selection);
 
-    const QFixed y = QFixed::fromReal(pos.y()) + line.y + line.ascent;
 
+
+    const qreal selectionY = pos.y() + line.y.toReal();
     const qreal lineHeight = line.height().toReal();
-    const qreal selectionY = (y - line.ascent).toReal();
 
     QFixed lastSelectionX = iterator.x;
     QFixed lastSelectionWidth;
@@ -1334,23 +1334,23 @@ void QTextLayout::drawCursor(QPainter *p, const QPointF &pos, int cursorPosition
     const qreal x = position.x() + l.cursorToX(cursorPosition);
 
     int itm = d->findItem(cursorPosition - 1);
-    QFixed ascent = sl.ascent;
+    QFixed base = sl.base();
     QFixed descent = sl.descent;
     bool rightToLeft = (d->option.textDirection() == Qt::RightToLeft);
     if (itm >= 0) {
         const QScriptItem &si = d->layoutData->items.at(itm);
         if (si.ascent > 0)
-            ascent = si.ascent;
+            base = si.ascent;
         if (si.descent > 0)
             descent = si.descent;
         rightToLeft = si.analysis.bidiLevel % 2;
     }
-    qreal y = position.y() + (sl.y + sl.ascent - ascent).toReal();
+    qreal y = position.y() + (sl.y + sl.base() - base).toReal();
     bool toggleAntialiasing = !(p->renderHints() & QPainter::Antialiasing)
                               && (p->transform().type() > QTransform::TxTranslate);
     if (toggleAntialiasing)
         p->setRenderHint(QPainter::Antialiasing);
-    p->fillRect(QRectF(x, y, qreal(width), (ascent + descent).toReal()), p->pen().brush());
+    p->fillRect(QRectF(x, y, qreal(width), (base + descent + 1).toReal()), p->pen().brush());
     if (toggleAntialiasing)
         p->setRenderHint(QPainter::Antialiasing, false);
     if (d->layoutData->hasBidi) {
@@ -1500,9 +1500,11 @@ qreal QTextLine::descent() const
 }
 
 /*!
-    Returns the line's height. This is equal to ascent() + descent() + 1.
+    Returns the line's height. This is equal to ascent() + descent() + 1
+    if leading is not included. If leading is included, this equals to
+    ascent() + descent() + leading() + 1.
 
-    \sa ascent() descent()
+    \sa ascent() descent() leading() setLeadingIncluded()
 */
 qreal QTextLine::height() const
 {
@@ -1510,6 +1512,51 @@ qreal QTextLine::height() const
 }
 
 /*!
+    \since 4.6
+
+    Returns the line's leading.
+
+    \sa ascent() descent() height()
+*/
+qreal QTextLine::leading() const
+{
+    return eng->lines[i].leading.toReal();
+}
+
+/*! \since 4.6
+
+  Includes positive leading into the line's height if \a included is true;
+  otherwise does not include leading.
+
+  By default, leading is not included.
+
+  Note that negative leading is ignored, it must be handled
+  in the code using the text lines by letting the lines overlap.
+
+  \sa leadingIncluded()
+
+*/
+void QTextLine::setLeadingIncluded(bool included)
+{
+    eng->lines[i].leadingIncluded= included;
+
+}
+
+/*! \since 4.6
+
+  Returns true if positive leading is included into the line's height; otherwise returns false.
+
+  By default, leading is not included.
+
+  \sa setLeadingIncluded()
+*/
+bool QTextLine::leadingIncluded() const
+{
+    return eng->lines[i].leadingIncluded;
+}
+
+
+/*!
     Returns the width of the line that is occupied by text. This is
     always \<= to width(), and is the minimum width that could be used
     by layout() without changing the line break position.
@@ -1712,6 +1759,9 @@ void QTextLine::layout_helper(int maxGlyphs)
         }
         const QScriptItem &current = eng->layoutData->items[item];
 
+        lbh.tmpData.leading = qMax(lbh.tmpData.leading + lbh.tmpData.ascent,
+                                   current.leading + current.ascent) - qMax(lbh.tmpData.ascent,
+                                                                            current.ascent);
         lbh.tmpData.ascent = qMax(lbh.tmpData.ascent, current.ascent);
         lbh.tmpData.descent = qMax(lbh.tmpData.descent, current.descent);
 
@@ -2042,7 +2092,9 @@ void QTextLine::draw(QPainter *p, const QPointF &pos, const QTextLayout::FormatR
 
 
     QTextLineItemIterator iterator(eng, i, pos, selection);
-    const QFixed y = QFixed::fromReal(pos.y()) + line.y + line.ascent;
+    QFixed lineBase = line.base();
+
+    const QFixed y = QFixed::fromReal(pos.y()) + line.y + lineBase;
 
     bool suppressColors = (eng->option.flags() & QTextOption::SuppressColors);
     while (!iterator.atEnd()) {
@@ -2065,7 +2117,7 @@ void QTextLine::draw(QPainter *p, const QPointF &pos, const QTextLayout::FormatR
             if (selection)
                 format.merge(selection->format);
 
-            setPenAndDrawBackground(p, pen, format, QRectF(iterator.x.toReal(), (y - line.ascent).toReal(),
+            setPenAndDrawBackground(p, pen, format, QRectF(iterator.x.toReal(), (y - lineBase).toReal(),
                                                            iterator.itemWidth.toReal(), line.height().toReal()));
 
             QTextCharFormat::VerticalAlignment valign = format.verticalAlignment();
@@ -2086,7 +2138,7 @@ void QTextLine::draw(QPainter *p, const QPointF &pos, const QTextLayout::FormatR
                 if (si.analysis.flags == QScriptAnalysis::Object && eng->block.docHandle()) {
                     QFixed itemY = y - si.ascent;
                     if (format.verticalAlignment() == QTextCharFormat::AlignTop) {
-                        itemY = y - line.ascent;
+                        itemY = y - lineBase;
                     }
 
                     QRectF itemRect(iterator.x.toReal(), itemY.toReal(), iterator.itemWidth.toReal(), si.height().toReal());
diff --git a/src/gui/text/qtextlayout.h b/src/gui/text/qtextlayout.h
index 90afac8..9f170f5 100644
--- a/src/gui/text/qtextlayout.h
+++ b/src/gui/text/qtextlayout.h
@@ -196,6 +196,10 @@ public:
     qreal ascent() const;
     qreal descent() const;
     qreal height() const;
+    qreal leading() const;
+
+    void setLeadingIncluded(bool included);
+    bool leadingIncluded() const;
 
     qreal naturalTextWidth() const;
     QRectF naturalTextRect() const;
diff --git a/src/gui/text/text.pri b/src/gui/text/text.pri
index b28ecd7..b7615a4 100644
--- a/src/gui/text/text.pri
+++ b/src/gui/text/text.pri
@@ -78,6 +78,7 @@ win32 {
 unix:x11 {
 	HEADERS += \
 		text/qfontengine_x11_p.h \
+		text/qfontdatabase_x11.cpp \
 		text/qfontengine_ft_p.h
 	SOURCES += \
 		text/qfont_x11.cpp \
diff --git a/src/gui/widgets/qcombobox.cpp b/src/gui/widgets/qcombobox.cpp
index 0e888d6..05e1e74 100644
--- a/src/gui/widgets/qcombobox.cpp
+++ b/src/gui/widgets/qcombobox.cpp
@@ -314,7 +314,7 @@ QSize QComboBoxPrivate::recomputeSizeHint(QSize &sh) const
 
 
         // height
-        sh.setHeight(qMax(fm.lineSpacing(), 14) + 2);
+        sh.setHeight(qMax(fm.height(), 14) + 2);
         if (hasIcon) {
             sh.setHeight(qMax(sh.height(), iconSize.height() + 2));
         }
diff --git a/src/gui/widgets/qdockwidget.cpp b/src/gui/widgets/qdockwidget.cpp
index a574262f..6710275 100644
--- a/src/gui/widgets/qdockwidget.cpp
+++ b/src/gui/widgets/qdockwidget.cpp
@@ -456,7 +456,7 @@ int QDockWidgetLayout::titleHeight() const
 
     int mw = q->style()->pixelMetric(QStyle::PM_DockWidgetTitleMargin, 0, q);
 
-    return qMax(buttonHeight + 2, titleFontMetrics.lineSpacing() + 2*mw);
+    return qMax(buttonHeight + 2, titleFontMetrics.height() + 2*mw);
 }
 
 void QDockWidgetLayout::setGeometry(const QRect &geometry)
diff --git a/src/gui/widgets/qfontcombobox.cpp b/src/gui/widgets/qfontcombobox.cpp
index 7b39823..806db59 100644
--- a/src/gui/widgets/qfontcombobox.cpp
+++ b/src/gui/widgets/qfontcombobox.cpp
@@ -194,7 +194,7 @@ QSize QFontFamilyDelegate::sizeHint(const QStyleOptionViewItem &option,
 //     font.setFamily(text);
     font.setPointSize(QFontInfo(font).pointSize() * 3/2);
     QFontMetrics fontMetrics(font);
-    return QSize(fontMetrics.width(text), fontMetrics.lineSpacing());
+    return QSize(fontMetrics.width(text), fontMetrics.height());
 }
 
 
diff --git a/src/gui/widgets/qlineedit.cpp b/src/gui/widgets/qlineedit.cpp
index 629e839..e4252b5 100644
--- a/src/gui/widgets/qlineedit.cpp
+++ b/src/gui/widgets/qlineedit.cpp
@@ -624,7 +624,7 @@ QSize QLineEdit::sizeHint() const
     Q_D(const QLineEdit);
     ensurePolished();
     QFontMetrics fm(font());
-    int h = qMax(fm.lineSpacing(), 14) + 2*d->verticalMargin
+    int h = qMax(fm.height(), 14) + 2*d->verticalMargin
             + d->topTextMargin + d->bottomTextMargin
             + d->topmargin + d->bottommargin;
     int w = fm.width(QLatin1Char('x')) * 17 + 2*d->horizontalMargin
diff --git a/src/gui/widgets/qplaintextedit.cpp b/src/gui/widgets/qplaintextedit.cpp
index 22438bf..fc61889 100644
--- a/src/gui/widgets/qplaintextedit.cpp
+++ b/src/gui/widgets/qplaintextedit.cpp
@@ -357,10 +357,8 @@ void QPlainTextDocumentLayout::layoutBlock(const QTextBlock &block)
     Q_D(QPlainTextDocumentLayout);
     QTextDocument *doc = document();
     qreal margin = doc->documentMargin();
-    QFontMetrics fm(doc->defaultFont());
     qreal blockMaximumWidth = 0;
 
-    int leading = qMax(0, fm.leading());
     qreal height = 0;
     QTextLayout *tl = block.layout();
     QTextOption option = doc->defaultTextOption();
@@ -381,9 +379,8 @@ void QPlainTextDocumentLayout::layoutBlock(const QTextBlock &block)
         QTextLine line = tl->createLine();
         if (!line.isValid())
             break;
+        line.setLeadingIncluded(true);
         line.setLineWidth(availableWidth);
-
-        height += leading;
         line.setPosition(QPointF(margin, height));
         height += line.height();
         blockMaximumWidth = qMax(blockMaximumWidth, line.naturalTextWidth() + 2*margin);