Avoid repeatedly trying to load unloadable plugins, causing slowness

In certain uncommon situations, where different Qt versions are used
on the same system, the plugin caching optimization may identify a dll
as a valid plugin, even though it will later fail to load. This fix
will avoid that Qt repeatdly tries to reopen such dlls, something
which caused a significant performance hit in these cases. E.g. where
Qt would unsuccessfully try to load a number of KDE image format plugins
for every image loading operation.

Task-number: QTBUG-10066
Reviewed-by: thiago
Reviewed-by: janarve

0 files changed, 0 insertions, 0 deletions