Fix line number tracking after a non-empty blank token

lib/liquid/block_body.rb

@@ -27,11 +27,11 @@ module Liquid
     private def parse_for_liquid_tag(tokenizer, parse_context)
       while token = tokenizer.shift
         case
-        when token.empty?
+        when token.empty? || token =~ WhitespaceOrNothing
-          # pass
+          # pass, but assign line_number below, since it could change even when
+          # the token is empty
         else
           unless token =~ LiquidTagToken
-            next if token =~ WhitespaceOrNothing
             # line isn't empty but didn't match tag syntax, yield and let the
             # caller raise a syntax error
             return yield token, token

test/integration/tags/liquid_tag_test.rb

@@ -74,6 +74,11 @@ class LiquidTagTest < Minitest::Test
     LIQUID
   end
 
+  def test_line_number_is_correct_after_a_blank_token
+    assert_match_syntax_error("syntax error (line 3): Unknown tag 'error'", "{% liquid echo ''\n\n error %}")
+    assert_match_syntax_error("syntax error (line 3): Unknown tag 'error'", "{% liquid echo ''\n  \n error %}")
+  end
+
   def test_cannot_open_blocks_living_past_a_liquid_tag
     assert_match_syntax_error("syntax error (line 3): 'if' tag was never closed", <<~LIQUID)
     {%- liquid