Improve IE expression string tokenizing

Author: xzyfer

debugger.hpp

@@ -489,6 +489,7 @@ inline void debug_ast(AST_Node* node, string ind = "", Env* env = 0)
     cerr << " [" << prettyprint(expression->value()) << "]" <<
       (expression->is_delayed() ? " {delayed}" : "") <<
       (expression->sass_fix_1291() ? " {sass_fix_1291}" : "") <<
+      (expression->quote_mark() != 0 ? " {qm:" + string(1, expression->quote_mark()) + "}" : "") <<
       " <" << prettyprint(expression->pstate().token.ws_before()) << ">" << endl;
   } else if (dynamic_cast<String_Schema*>(node)) {
     String_Schema* expression = dynamic_cast<String_Schema*>(node);

parser.cpp

@@ -1415,6 +1415,7 @@ namespace Sass {
     Token str(lexed);
     const char* i = str.begin;
     // see if there any interpolants
+    const char* q;
     const char* p = find_first_in_interval< exactly<hash_lbrace> >(str.begin, str.end);
     if (!p) {
       String_Constant* str_node = new (ctx.mem) String_Constant(pstate, normalize_wspace(string(str.begin, str.end)));
@@ -1424,8 +1425,16 @@ namespace Sass {
 
     String_Schema* schema = new (ctx.mem) String_Schema(pstate);
     while (i < str.end) {
+      q = find_first_in_interval< alternatives< exactly<'"'>, exactly<'\''> > >(i, str.end);
       p = find_first_in_interval< exactly<hash_lbrace> >(i, str.end);
-      if (p) {
+      if (q && (!p || p > q)) {
+        if (i < q) {
+          (*schema) << new (ctx.mem) String_Constant(pstate, string(i, q)); // accumulate the preceding segment if it's nonempty
+        }
+        (*schema) << new (ctx.mem) String_Constant(pstate, string(q, q+1)); // capture the quote mark separately
+        i = q+1;
+      }
+      else if (p) {
         if (i < p) {
           (*schema) << new (ctx.mem) String_Constant(pstate, string(i, p)); // accumulate the preceding segment if it's nonempty
         }