Fix scrollbar randomly popping up in QPlainTextEdit

When a line break was detected, we would retain the value of the
right bearing for the character after the break instead of resetting it
to the right bearing of the previous value. This could in some cases
cause the bounding rect of the text to be wrong, and could cause
unnecessary horizontal scrollbars to pop up. It was especially visible
when using WrapAnywhere. Visible e.g. in the compile output in Creator.

Done-by: mae
Reviewed-by: Eskil
Reviewed-by: Lars

1 files changed, 30 insertions, 0 deletions

diff --git a/tests/auto/qtextlayout/tst_qtextlayout.cpp b/tests/auto/qtextlayout/tst_qtextlayout.cpp
index f798faf..659ba1a 100644
--- a/tests/auto/qtextlayout/tst_qtextlayout.cpp
+++ b/tests/auto/qtextlayout/tst_qtextlayout.cpp
@@ -122,6 +122,7 @@ private slots:
     void smallTextLengthWrapAtWordBoundaryOrAnywhere();
     void testLineBreakingAllSpaces();
     void lineWidthFromBOM();
+    void textWidthVsWIdth();
 
 
 private:
@@ -1359,5 +1360,34 @@ void tst_QTextLayout::glyphLessItems()
     }
 }
 
+void tst_QTextLayout::textWidthVsWIdth()
+{
+    QTextLayout layout;
+    QTextOption opt;
+    opt.setWrapMode(QTextOption::WrapAnywhere);
+    layout.setTextOption(opt);
+    layout.setText(QString::fromLatin1(
+                       "g++ -c -m64 -pipe -g -fvisibility=hidden -fvisibility-inlines-hidden -Wall -W -D_REENTRANT -fPIC -DCORE_LIBRARY -DIDE_LIBRARY_BASENAME=\"lib\" -DWITH_TESTS "
+                       "-DQT_NO_CAST_TO_ASCII -DQT_USE_FAST_OPERATOR_PLUS -DQT_USE_FAST_CONCATENATION -DQT_PLUGIN -DQT_TESTLIB_LIB -DQT_SCRIPT_LIB -DQT_SVG_LIB -DQT_SQL_LIB -DQT_XM"
+                       "L_LIB -DQT_GUI_LIB -DQT_NETWORK_LIB -DQT_CORE_LIB -DQT_SHARED -I../../../../qt-qml/mkspecs/linux-g++-64 -I. -I../../../../qt-qml/include/QtCore -I../../../."
+                       "./qt-qml/include/QtNetwork -I../../../../qt-qml/include/QtGui -I../../../../qt-qml/include/QtXml -I../../../../qt-qml/include/QtSql -I../../../../qt-qml/inc"
+                       "lude/QtSvg -I../../../../qt-qml/include/QtScript -I../../../../qt-qml/include/QtTest -I../../../../qt-qml/include -I../../../../qt-qml/include/QtHelp -I../."
+                       "./libs -I/home/ettrich/dev/creator/tools -I../../plugins -I../../shared/scriptwrapper -I../../libs/3rdparty/botan/build -Idialogs -Iactionmanager -Ieditorma"
+                       "nager -Iprogressmanager -Iscriptmanager -I.moc/debug-shared -I.uic -o .obj/debug-shared/sidebar.o sidebar.cpp"));
+
+    // textWidth includes right bearing, but it should never be LARGER than width if there is space for at least one character
+    for (int width = 100; width < 1000; ++width) {
+        layout.beginLayout();
+        QTextLine line = layout.createLine();
+        line.setLineWidth(width);
+        layout.endLayout();
+
+        qreal textWidthIsLargerBy = qMax(qreal(0), line.naturalTextWidth() - line.width());
+        qreal thisMustBeZero = 0;
+        QCOMPARE(textWidthIsLargerBy, thisMustBeZero);
+    }
+}
+
+
 QTEST_MAIN(tst_QTextLayout)
 #include "tst_qtextlayout.moc"