Steps to Reproduce: 1. Bookmark http://www.mozilla.org/projects/minefield/ 2. Search Google for "testmine" 3. Type "mine" into the location bar 4. Quickly hit Backspace and "e" (resulting in searches for "min" and again "mine") 5. Goto 4 Actual results: *Some* times the Google URL is listed first, although "mine" isn't at any word boundary. When repeating step 4, there are at least two different result orders with no discernible reason for the difference. Expected results: All other things being equal, entering a search term such as "mine" should always produce the same results in the same order (preferring those results where the search term starts at a word boundary).

This happens when you don't have enough word boundary results and start dipping into non-word boundary results and the non-word boundary results have higher frecency than the word boundary ones.

(In reply to comment #2) That's not how the feature was advertised in bug 429531, though, or was it?

Bug 426166 is caused by adaptive learning not knowing about additional characters. This bug showed up after bug 429531 which is about word boundary matches, so adjusting title accordingly. 1) visit http://en.wikipedia.org/wiki/Zilla 2) visit http://www.mozilla.org/ 3) Search for "zill" (results are Zilla then mozilla.org) 4) Search for "zilla" (results are mozilla.org then Zilla)

Use the previous query twice just like we do a full query twice if necessary.

beltzner: This problem will get worse if we increase the number of results in bug 431809 (12 results -> 30 results) because we're more likely to "match anywhere" after running out of word boundary matches, and then typing more would cause the higher-frecency "match anywhere" results to show above word boundary ones.

I'm not sure that this blocks, tbh, would like mconnor to weigh in. Yes, shifting results are bad, and it would be good polish to take, but I think we can live without it. If Dietrich has time to review the patch, though, that'd be awesome.

Per policy at https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Inactive_Bugs. If this bug is not an enhancement request or a bug not present in a supported release of Firefox, then it may be reopened.