- Optimized empty QUrl creation

    * [QTBUG-4030] Empty QUrls no longer allocate memory now

 * See list of Important Behavior Changes below

 - QFile

    * Improve performance of getting the canonical filename on Linux

      and Symbian by using realpath() system call.

    * Avoid stat() when opening a file.

 - QLibrary and QPluginLoader

    * Do not look at the Qt patch-level version embedded in plugins'

      buildkeys when trying to determine if the plugin is compatible

 - QProcessEnvironment

    * [QTBUG-6701] Ensure we don't crash in operator==

 - QTextEncoder

    * [merge request 399] QTextEncoder::fromUnicode as QT3 support

      member

 - QXmlStreamreader

    * [merge request 1926] Fix parsing of DTDs that contain empty markup

      declarations.

 - QApplication

    * [QTBUG-6654] Fix crashes when deleting QWidgets in touch event

      handlers.

 - QGraphicsEffect

    * [QTBUG-5918] Fixed redraw bugs when using graphics effects on

      items while animating them by transformations.

 - QGraphicsItem

    * [QTBUG-5917] Fixed memory leaks when removing a QGraphicsEffect from

      a QGraphicsItem or QWidget with setGraphicsEffect(0).

    * [QTBUG-5859] Fixes incorrect rounding of the exposed rectangle of the

      QGraphicsItem causing painting issues when scaling the QGraphicsView.

    * [QTBUG-5071] Fixes transformation problems when grouping/ungrouping

      the item with a QGraphicsItemGroup.

 - QGraphicsObject

    * 'id' property was removed. Use the 'objectName' property instead.

 - QGraphicsScene

    * [QTBUG-6654] Fix crashes when deleting QGraphicsItems in touch

      event handlers.

 - QGraphicsView

    * [QTBUG-6935] When using CacheBackground, the background is now

      correctly repainted after the QGraphicsView is shown after being

      hidden.

    * [QTBUG-6835] Mouse tracking is now automatically enabled when using

      AnchorUnderMouse for view transformation.

    * [QTBUG-6958] Fix speed regression in _q_polishItems()

    * [QTBUG-6544] Fix a crash on the focus chain when removing items from 

      the scene.

    * Fix a crash in KDE/Plasma with QGraphicsView with topLevels.

 - QGraphicsWidget

    * [QTBUG-6272] Only call updateFont if the font has changed.

 - QPainter

    * [QTBUG-5939] Fixed incorrect redirection matrix that was causing

      wrong transformation for QGraphicsProxyWidgets.

    * [QTBUG-6684] Added optimizations of 32-bit blend functions

      for ARM platforms with NEON support.

    * [QTBUG-6840] Fixed load() to not modify referenced copies.

    * [QTBUG-5840] Fixed a crash in fromImage() when passing in a null image.

    * [QTBUG-6116] Fixed memory leak where a global object was not destroyed

      at program exit.

 - QPixmapCache

    * Fixed a small leak when using the new QPixmapCache::Key based API.

 - QPrinter

    * [QTBUG-3412] QGraphicsProxyWidgets are now rendered correctly when

      printing a QGraphicsScene to PDF format.

 - QRasterPixmapData

    * [QTBUG-6985] Fixed metric() to return the correct height in mm.

 - QTextDocument

    * [QTBUG-5397] Fixed printing of QTextDocuments not including custom

      text objects.

    * [QTBUG-6051] Fixed an endless loop when printing a QTextDocument.

 - QDBusConnection

    * [QTBUG-5979] Fixed the signal-delivery mechanism to update

      correctly when the sender name changes/appears on the bus.

    * [QTBUG-7041] Fixed marshalling of booleans in release mode.

    * [QT-2307] Fixed calls with the QDBus::BlockWithGui mode.

 - QDBusInterface

    * Made it continue working even when the remote object

      introspection fails.

 - QDBusInterface and qdbuscpp2xml

    * [QTBUG-5563] Fixed an issue with generating annotations in

      signals.

 - QDBusPendingReply and QDBusReply

    * [QTBUG-6571] Fixed a crash that would happen if you tried to

      make a call with a disconnected QDBusConnection.

QtMultimedia

------------

 - QAudioOutput

   * [Merge request 418] Fixed compilation the example provided for

     QAudioOutput::start.

 - QNetworkAccessManager

    * HTTP: Send our locale with the HTTP request.

    * HTTP: Start Accept-language and Authorization header with capital letter.

    * HTTP: Fix caching algorithm, matching RFC 2612 and the documentation.

    * HTTP [QTBUG-7060]: Fix an issue with headers like "private, max-age=300".

    * file: Introduce special subclass for higher performance with file:// URLs.

 - QTcpSocket

    * [QTBUG-5799] Fix waitForConnected() on Windows.

 - QNetworkProxyFactory

    * Fixed systemProxyForQuery(), it could sometimes return invalid empty list

      on Windows.

 - QNetworkCookieJar

    * [QTBUG-5815] Do not check paths when accepting cookies.

 - QHostInfo

    * Use five parallel threads for host lookup instead of one.

 - QGL2PaintEngineEx

    * Performance: Don't mark brush as dirty if it hasn't changed.

    * Performance: Use 3x3 PMV matrices rather than 4x4.

    * Performance: Move the 0.5 offset we add for aliased rendering to

      updateMatrix().

    * Performance: Remove superfluous enable/disable vertex attrib arrays.

    * Performance: Track the glVertexAttribPointer and only update it if it's

      changed.

    * [QTBUG-7094]  Introduce new "snapToPixelGrid" flag for drawText.

    * bindTexture(QImage): Reduce double-copying of textures when flipping.

    * [QTBUG-6454] Better EGL extension checking to avoid prefix problems

      with EGL_foo matching EGL_foo_bar.

    * [QTBUG-6217] Work around problems with glColor4ub() on Intel Q45/Q43

      Express by consistently using glColor4f() everywhere.

    * bindTexture(QImage): Fix GL_BGRA formats under OpenGL/ES by using

      the same value for both internal and external texture formats.

    * [QTBUG-5041] Disable depth testing while in renderText().

 - QGLEngineSelector

    * [QTBUG-5638] Detect GL2 based on fragment shaders, not programs.

      Fragment programs are a GL1 feature.

 - QGLFramebufferObject

    * [QTBUG-6712] Update docs to better explain how QPainter changes

      the GL state when used on an FBO.

 - QGLGlyphCache

    * [QTBUG-6936] Fix memory leak of QGLGlyphCoord objects.

 - QGLPaintDevice

    * [QTBUG-6204] Rebind window surface FBO after native GL rendering.

 - QGLPixmapData

    * [QTBUG-6902] Align GL_RGB data on a 4-byte line boundary.

 - QGLWidget

    * [QTBUG-5002, QTBUG-6931] Fixed QGLWidget::renderText().

    * Fixed WA_TranslucentBackground for QGLWidgets on X11/EGL.

    * Fix EGL surface leaks when re-parenting on X11/EGL.

 - QTriangulatingStroker

    * [QTBUG-6045] Crash in dashed line handling in the GL stroker.

QtOpenVG

 - [QT-2555] Automatically destroy VG pixmaps when the last window surface

   goes away to reduce memory consumption of backgrounded applications.

 - [QTBUG-6639] Recover from out-of-memory when creating VGImage's.

 - [QT-2554] Add a VGImage allocation pool to support reclaiming older

   images when the GPU runs out of memory.

 - [QTBUG-7051] Reset the OpenVG scissor after a native painting call-out.

 - [QTBUG-7015] Avoid deep copies of QImage in QImage::bits() calls.

QtWebKit

--------

 - Fixed user agent string on Symbian (webkit.org/b/31961).

 - QWebInspector: Don't disable when hiding (webkit.org/b/31851).

 - Fix JavaScript prompt behaviour for empty/null strings (webkit.org/b/30914).

 - Fixed lastIndexOf() on Symbian (webkit.org/b/31773).

 - Fixed crash with Flash on Windows with MinGW.

 - Fixed wrapping of QObjects with recurring identity (webkit.org/b/31681).

 - Fixed compilation with ICC.

 - Fixed assertion when dragging SVG images (webkit.org/b/32511).

 - Added the framecapture example to the default build (merge request 2235)

 - Fixed crash with ACID3 test on Symbian

 - Fixed security issue XSL stylesheets and security origins.

 - [QTBUG-5373] Fixed QSqlRelationalTableModel doesn't correctly work with

   relation in other database schema.

 - [QTBUG-5298] (OCI) Fixed QSqlDatabase.tables() does not work with system

   tables.

 - [QTBUG-6421] Fixed setForwardOnly() for both OCI and SQLite.

 - [QTBUG-6618] (ODBC) Fixed segfault when error string is larger than 256

   chars.

 - [QTBUG-4461] (OCI) Fixed problem with clobs being handled as binary.

QtSvg

 - QSvgRenderer

    * [QTBUG-6867] Fixed regression in the parsing of paths with relative

      offsets.

    * [QTBUG-6899] Fixed crash when parsing invalid coordinate list.

 - QtXmlPatterns

    * [QTBUG-6771] Fixed static builds.

 - JPEG plugin

    * Remove obsolete parameter string handling.

    * [QT-2023] Re-implement ScaledSize, ClipRect, ScaledClipRect with

      libjpeg features for greater performance.

 - PBM plugin

    * [QTBUG-6937] Use Mono instead of MonoLSB when writing pbm files.

 - TIFF plugin

    * [QTBUG-6870] BitsPerSample should default to 1 in TIFF files.

 - PNG plugin

    * [QTBUG-7161] Avoid a deep copy of QImage::bits() in the png writer.

 - [QTBUG-6755] Ensure we don't call select(2) with a negative timeout

   if the timer expires during timeout recalculation.

 - Added mkspecs for Sun CC that enable -library=stlport by default,

   to restore STL capability with that compiler.

 - [QTBUG-6576] Fixed compilation on HP-UX 11.11.

 - [QTBUG-6961] Fixed compilation on HURD.

 - [QTBUG-5732] Fixed querying of GLX extensions under X11.

 - [QTBUG-5547] Fixed handling of the "..." button.

 - Added new mkspec for Maemo targets (linux-g++-maemo).

 - Added new mkspec for Scratchbox host compiler (unsupported/linux-host-g++).

 - QGuiEventDispatcherGlib (internal class)

    * Fix regression introduced in 4.6.0 that could cause X11 event

      processing to starve timer events.

 - QFileSystemWatcher

    * [QTBUG-4840] Fix memory leak in the dnotify implementation.

 - QIcon

    * [QTBUG-6121] Fixed a problem causing svg-based icon themes to look fuzzy.

 - QGtkStyle

    * [QTBUG-6484] Ensure that gtk-enable-mnemonics is respected.

 - [QTBUG-5145] Compile fixes for win32-icc.

 - QAtomicPointer

    * [QTBUG-6079] Fix compilation for 64-bit Windows targets.

 - QEventDispatchWin32 (internal class)

    * [QTBUG-6083] Fix a performance regression introduced in 4.6.0

      that would cause all Qt posted events to be sent at 15-16ms

      intervals (instead of as quickly as possible).

 - Vista/XP styles

    * [QTBUG-6271] Fixed a compatibility issue with MDI windows in 

      certain non-standard themes.

 - QPixmap

   * [QTBUG-5070] Fixed a crash on Mac that could occur when loading

     pixmaps of different sizes into the same QPixmap object.

 - [QTBUG-6973] Fixed a memory leak when using QWidget::setWindowIcon() in

   Carbon.

 - [QTBUG-5186] Fixed a bug which caused drag and drop icons to show 

   incorrectly.

 - [QTBUG-6636] Fixed a crash due to stack overflow in QColorDialog on Cocoa.

 - [QTBUG-6378] Fix a text cursor rendering bug.

 - [QTBUG-6636] Fixed a crash when calling removeToolBar on Mac native toolbars

   using Cocoa.

 - [QTBUG-5613] Fixed a bug where the application refused to quit when showing

   a single modal dialog.

 - Gestures are now available for the Carbon port also when building Qt against

   SDK < 10.6

Qt for Symbian

--------------

 - QApplication

   * [QTBUG-6098] Added a flag to avoid construction of application panes.

 - Other:

   * [QTBUG-4990] Rewrote most of the regular pointer handling.

   * [QTBUG-6863] Fixed static linking on Mac.

   * [QTBUG-6760] Fixed display of action shortcut in action editor.

   * [QTBUG-6505] Fixed handling of QHeaderView properties.

   * [QTBUG-5335] Fixed handling of layout margins of custom containers.

 - uic

   * [QTBUG-5824] Fixed code generation to generate a call to

     QMainWindow::setCentralWidget() for promoted widgets as well.

 - Phonon

   * Include headers have been changed. The only official method for

     including Phonon headers is <phonon/ClassName> or

     <phonon/classname.h>. This change was necessary because of

     frameworks on Mac.

     Compatibility is provided for <Phonon/*> includes, but is not

     guaranteed to work. Including <phonon> and <Phonon> is not

     supported.