Allowing the parser to parse an arbitrary interval rather than all the way to the null terminator.

document.cpp

@@ -23,6 +23,7 @@ namespace Sass {
       source = new char[len + 1];
       std::fread(source, sizeof(char), len, f);
       source[len] = '\0';
+      end = source + len;
       std::fclose(f);
       own_source = true;
     }
@@ -48,11 +49,20 @@ namespace Sass {
     source = new char[len + 1];
     std::fread(source, sizeof(char), len, f);
     source[len] = '\0';
+    end = source + len;
     std::fclose(f);
     position = source;
     context.source_refs.push_back(source);
     ++context.ref_count;
   }
+  
+  Document::Document(Token t, Context& context)
+  : context(context)
+  {
+    
+    
+    
+  }
 
   Document::~Document() {
     --context.ref_count;

document.hpp

@@ -18,6 +18,7 @@ namespace Sass {
     string path;
     char* source;
     const char* position;
+    const char* end;
     size_t line_number;
     bool own_source;
 
@@ -28,6 +29,7 @@ namespace Sass {
     
     Document(string path, char* source = 0);
     Document(string path, Context& context);
+    Document(Token t, Context& context);
     ~Document();
     
     template <prelexer mx>

document_parser.cpp

@@ -8,7 +8,7 @@ namespace Sass {
   {
     lex<optional_spaces>();
     root << Node(Node::flags);
-    while(*position) {
+    while(position < end) {
       if (lex< block_comment >()) {
         root << Node(Node::comment, line_number, lexed);
       }