fd119e986d
ContentProviders are allowed to return null and both of our contact directories (Focus and Exchange) actually do when they find no data to return. The problem is that when LoaderManager receives a result from a loader, it checks if the result is the same as previously received. That's fine, as long as the loader always returns a different result. Now consider a loader that returns null when it cannot produce the result. What we are seeing is that if the loader is rapidly restared and returns null twice in a row, the null is never delivered to the callbacks. In the case of the reported bug, the scenario is this: 1. We look for "foo" 2. Data for "foo" comes from a directory and we display it 3. We hit backspace twice in rapid succession. Each time we hit backspace, the loader is restared, but since we do this very fast, the second restart overrides the first. So far so good. 4. The directories are programmed to return null if the query string is less than 3 characters long, so the loader returns null twice. 5. Loader manager looks at the final result, compares it to the previous result and since they are the same (both null) concludes that it does not need to deliver either of them. 6. The UI attempts to show the stale data and blows up Bug: 3352125 Change-Id: I3e5bc505faa03f72ebe5cb010377a740f5c7d5b6