Searchs of short terms return wrong results

I had two concerns: (a) a minor concern that the code didn't seem elegant to me, and thinking that there might be a more elegant way to set the $simple variable, (b) a bigger concern that the additional case which sets the $simple variable (introduced by this patch) is as narrow as it can be, and doesn't introduce full table queries on the {search_dataset} more often than needed.

if there are short words, i.e. words smaller than the minimum_word_size, then it's not a simple query and {search_dataset} must be used. The simple test for phrases is handled elsewhere. So this test just checks for simple AND and simple OR terms, and if any of the words are smaller than the minimum_word_size, then, it's not so simple after all.

If the word is too small then $count2 == 0 and $simple is set to FALSE. @chx, does that make sense, or do you still think I'm seeing something wrong?

How about changing both $count variables to $num_new_scores and $num_valid_words, respectively. The first count, actually keeps track of the number of words that were added to the $scores array, that weren't already there... thus the suggested variable name, while the second count keeps track of the number of valid words regardless of whether they've already been added to the $scores array or not.

search_parse_query() first the breaks the search phrase into individual array elements, with the exception that expressions are still lumped into a single array. Then _search_parse_query is called on each of these array elements.

If you search for alpha beta, which looks for the words alpha and beta, search_parse_query() first puts this into the $keys['positive'] array where each of these words in the array('alpha', 'beta'). Then _search_parse_query() is called twice, once with each of these words, and $num_valid_words is set to 1, on each call.

If you search for "alpha beta", which looks for the words alpha and beta, but also does a second pass using {search_dataset} to make sure that these two words occur next to each other as in a phrase search for "alpha beta", This time, search_parse_query() puts the two words into a single array element, and _search_parse_query() is called only once, and the explode and loop in _search_parse_query, then iterate over both words, and $num_valid_words returns 2.

If either of these words is smaller than the minimum_word_size, We need to set $simple to FALSE We actually only need to figure this out for the first case, the AND case, because we already catch phrase searches on line 1285. So, looking at the first case, the AND search, _search_parse_query is called twice, once with each word. One of these calls with return $num_valid_words of 1, and the other call will return $num_valid_words of 0. On that second call that returns $num_valid_words of 0, $simple will be set to FALSE.

At least that's what I think (and hope) is happening.