Bug 324227

Description John Cortell 2010-09-01 12:59:51 EDT

This applies to any attributes of CVSProviderPlugin that are set by the CVS UI plugin, not just the 'auto share on import' one.

I ran into a situation where some code calls into CVSProviderPlugin.isAutoshareOnImport() and that returns false (unexpected value), but if I delay the call a bit, it returns true (expected value). The problem is that the CVSProviderPlugin implementation depends on the CVS UI plugin having been loaded, which may be in progress, but not far enough where CVSProviderPlugin has been updated by it.In general, having a non-UI plugin claim and publish knowledge that is truly only known by its UI counterpart seems misleading and fragile.

This unreliability can be demonstrated in stock eclipse with just a couple of tweaks. I've attached a patch file. To reproduce the problem, apply the patch and launch a clean runtime workbench (one that has no projects). In that workbench, do the following

1. Add a CVS repository for whatever projects you normally work with.
2. Do 'File > Import > General > Existing Projects into Workspace'
3. Hit the 'Browse...' to select a root directory. Pick any project you already have checked out from the repository in step 1, in any workspace. Doesn't matter which or where it is.
4. Hit Finish to initiate the import operation

In the console of the development workbench, you will see something similar to this:

CVS auto share on import is off at this point (0ms elapsed)
CVS auto share on import is off at this point (94ms elapsed)
[...snip]
CVS auto share on import is off at this point (3766ms elapsed)
CVS auto share on import is off at this point (3875ms elapsed)
Finally...CVS auto share on import is ON (3969ms elapsed)

This proves that CVSTeamProviderType would proceed under the impression that auto-share-on-import is off when in fact the preference is on. And if you tweak the code to not wait at all, then you'll see that the imported project ends up lacking CVS awareness. Of course, this is all due to the sleep in the CVSUIPlugin.start(). But this is a rig just to show the race condition can happen. Believe me, this happened without any rigging in my situation. The workaround for me is to force the loading of the CVS UI plugin. However, this is really an ugly remedy, and of course it was only obvious after many hours of troubleshooting.