Plugins should be re-cached if keys() returns a different result from the cached keys

Qt's plugin cache re-caches a plugin if its modification date is different from the cached modification date. Thus a rebuilt plugin will be re-cached.

However, this is not the case when considering the keys of a plugin. The cached keys of a plugin are not checked against what the plugin's keys() function returns, so if the result of keys() depends on run-time conditions, the current keys of the plugin will never be available.

The plugin cache mechanism should re-cache the plugin if its keys() function returns different values from the cached keys.

update:
Bumped to SFR due to potential large impact in performance of startup time.