Qt 5.15.2 is a bug-fix release. It maintains both forward and backward
compatibility (source and binary) with Qt 5.15.1.

For more details, refer to the online documentation included in this
distribution. The documentation is also available online:

  https://doc.qt.io/qt-5.15/index.html

The Qt version 5.15 series is binary compatible with the 5.14.x series.
Applications compiled for 5.14 will continue to run with 5.15.

Some of the changes listed in this file include issue tracking numbers
corresponding to tasks in the Qt Bug Tracker:

  https://bugreports.qt.io/

Each of these identifiers can be entered in the bug tracker to obtain more
information about a particular change.

****************************************************************************
*                   Important Behavior Changes                             *
****************************************************************************

****************************************************************************
*                          Library                                         *
****************************************************************************

 - [QTBUG-85018] Update QShaderFormat matching logic to account for RHI shader snippets
   OpenGLCompatibility/NoProfile should not match RHI shader snippets.
   The bug was: [REG: 5.14->5.15] QOpenGLShader::compile(Fragment):
   ERROR: 4:2: 'add' : syntax error syntax error
 - [QTBUG-86436] Only set the format to 1.0 if it was not changed due to OpenGL
   Since the userRequestedApi variable can be set when a second
   Qt3DWindow is created (since the environment variable is set after the
   first time). Then we should be sure to only set the format version to
   1.0 if it was not already set due to OpenGL being used.
   The bug was: Shader errors if there are multiple windows
 - [QTBUG-86721] Only use surfaceSize if m_surfaceSize is not valid
   This amends 2e3607aa120324f60832ca1cd42aaeaf22cc148d which made it
   always use surfaceSize. But if m_surfaceSize->size() is valid then
   this should be used as it will account for HighDPI setups.
   The bug was: [Regression] Scene3D rendering with underlay composition
   on HighDpi display is incorrect.
 - [QTBUG-84847] Rework Scene3D to fix potential crash on shutdown
   - Rework Scene3DRenderer/Scene3DItem to remove coupling and help
   simplify the flow - Introduce a Scene3DManagerNode to manager lifetime
   of the Scene3DRenderer. Rely on the Scene3DManagerNode dtor to know to
   shutdown the Qt3D renderer in the proper thread. - Try to handle the
   fact that destruction order between Item and SGNode is random by using
   an AspectEngineDestroyer helper - Stop using a sharedptr to store the
   QEntity on the Scene3DItem side. This can lead to crashes as the
   AspectEngine assumes it is the sole owner of the Entity ptr.
   Change-Id: I14915705eb9ab1195b2b783cbbb45076acc2ac1a
   The bug was: Scene3D crashes on destruction

Third-Party Code
----------------

 - Also document sub-projects that are part of the Assimp project: Clipper,
   irrXML, Open3DGC, OpenDLL-Parser, Poly2Tri, RapidJSON, Unzip, Utf8Cpp, and
   Zip.

 - Fix issue in the documentation that caused attributions for imgui
   third-party code to not show up.