merge from HEAD for bugs 45734 & 45736
Fix for 45734 & 45736
merge from HEAD to fix 45668 & 45612
Fix for PR 45818 doesn't solve the problem. Fall back to the previous version.
Fix for PR 45818: NPE when closing the workbench.
CSourceManager.java: implements adapters for 'ISourceMode' and 'IPersistableSourceLocator'.