Treat coordinates array with nil as a blank query.

This addresses:
https://github.com/alexreisner/geocoder/issues/322

lib/geocoder/query.rb

@@ -40,7 +40,13 @@ module Geocoder
     # Is the Query text blank? (ie, should we not bother searching?)
     #
     def blank?
-      !!text.to_s.match(/^\s*$/)
+      # check whether both coordinates given
+      if text.is_a?(Array)
+        text.compact.size < 2
+      # else assume a string
+      else
+        !!text.to_s.match(/^\s*$/)
+      end
     end
 
     ##

test/query_test.rb

@@ -20,6 +20,11 @@ class QueryTest < Test::Unit::TestCase
     assert !Geocoder::Query.new("Москва").blank? # no ASCII characters
   end
 
+  def test_blank_query_detection_for_coordinates
+    assert Geocoder::Query.new([nil,nil]).blank?
+    assert Geocoder::Query.new([87,nil]).blank?
+  end
+
   def test_coordinates_detection
     assert Geocoder::Query.new("51.178844,5").coordinates?
     assert Geocoder::Query.new("51.178844, -1.826189").coordinates?