Permit loading plugins built with future major Qt releases (4.x)

This check is too paranoid for us because it prevents from using symbol files
in full potential. Fine-grained package level dependencies should ensure that
the required version of the Qt Library is installed which might not necessarily
be the latest Qt 4.x the plugin was built against because the plugin actually
did not use any of new symbols in the Qt Library.

However, removal of this check might still increase likelihood of crashes when:

1) loading a new incompatible version of plugin into a running process still
using an old Qt Library. This might happen right after upgrade;

2) user tries to load incompatible non-packaged plugin;

but it's an acceptable compromise. Here we trade more bullet proof protection
from rare user faults or weird system misconfigurations for more flexibility,
installability and expand of forward binary compatibility beyond the same Qt
4.x whenever possible.

Gbp-Pq: Name 23_permit_plugins_built_with_future_qt.diff

diff --git a/src/corelib/plugin/qlibrary.cpp b/src/corelib/plugin/qlibrary.cpp
index 9a42761c1a0ed06ffc71eb2ecd256af593c47cd2..c9ed8c9b9895d4c8c8516448a402afeb4b8de932 100644 (file)
--- a/src/corelib/plugin/qlibrary.cpp
+++ b/src/corelib/plugin/qlibrary.cpp
@@ -834,7 +834,7 @@ bool QLibraryPrivate::isPlugin(QSettings *settings)
 
     pluginState = IsNotAPlugin; // be pessimistic
 
-    if ((qt_version & 0x00ff00) > (QT_VERSION & 0x00ff00) || (qt_version & 0xff0000) != (QT_VERSION & 0xff0000)) {
+    if ((qt_version & 0xff0000) != (QT_VERSION & 0xff0000)) {
         if (qt_debug_component()) {
             qWarning("In %s:\n"
                  "  Plugin uses incompatible Qt library (%d.%d.%d) [%s]",