Rescue and re-raise syntax errors in Template#parse to add line numbers.

This can be done now that the parse context has the line number
information, so it doesn't need to be added on closer to the original
exception.  This has the advantage of not having to rescue and re-raise the
exception multiple times, and simplifies liquid-c which would otherwise
have to rescue the exception in BlockBody#parse.

lib/liquid/block_body.rb

@@ -15,37 +15,32 @@ module Liquid
     def parse(tokenizer, parse_context)
       parse_context.line_number = tokenizer.line_number
       while token = tokenizer.shift
-        begin
-          unless token.empty?
-            case
-            when token.start_with?(TAGSTART)
-              if token =~ FullToken
-                tag_name = $1
-                markup = $2
-                # fetch the tag from registered blocks
-                if tag = registered_tags[tag_name]
-                  new_tag = tag.parse(tag_name, markup, tokenizer, parse_context)
-                  @blank &&= new_tag.blank?
-                  @nodelist << new_tag
-                else
-                  # end parsing if we reach an unknown tag and let the caller decide
-                  # determine how to proceed
-                  return yield tag_name, markup
-                end
+        unless token.empty?
+          case
+          when token.start_with?(TAGSTART)
+            if token =~ FullToken
+              tag_name = $1
+              markup = $2
+              # fetch the tag from registered blocks
+              if tag = registered_tags[tag_name]
+                new_tag = tag.parse(tag_name, markup, tokenizer, parse_context)
+                @blank &&= new_tag.blank?
+                @nodelist << new_tag
               else
-                raise_missing_tag_terminator(token, parse_context)
+                # end parsing if we reach an unknown tag and let the caller decide
+                # determine how to proceed
+                return yield tag_name, markup
               end
-            when token.start_with?(VARSTART)
-              @nodelist << create_variable(token, parse_context)
-              @blank = false
             else
-              @nodelist << token
-              @blank &&= !!(token =~ /\A\s*\z/)
+              raise_missing_tag_terminator(token, parse_context)
             end
+          when token.start_with?(VARSTART)
+            @nodelist << create_variable(token, parse_context)
+            @blank = false
+          else
+            @nodelist << token
+            @blank &&= !!(token =~ /\A\s*\z/)
           end
-        rescue SyntaxError => e
-          e.line_number ||= parse_context.line_number
-          raise
         end
         parse_context.line_number = tokenizer.line_number
       end

lib/liquid/parser_switching.rb

@@ -8,7 +8,6 @@ module Liquid
         begin
           return strict_parse_with_error_context(markup)
         rescue SyntaxError => e
-          e.line_number = line_number
           @options.warnings << e
           return lax_parse(markup)
         end
@@ -20,6 +19,7 @@ module Liquid
     def strict_parse_with_error_context(markup)
       strict_parse(markup)
     rescue SyntaxError => e
+      e.line_number = line_number
       e.markup_context = markup_context(markup)
       raise e
     end

lib/liquid/template.rb

@@ -120,6 +120,9 @@ module Liquid
       @root = Document.parse(tokenize(source), parse_context)
       @warnings = parse_context.warnings
       self
+    rescue SyntaxError => e
+      e.line_number ||= parse_context.line_number
+      raise
     end
 
     def registers