Improve parent selector handling in selector schema (#2358)

Author: mgreter

src/ast_def_macros.hpp

@@ -19,6 +19,10 @@ class LocalOption {
       this->orig = var;
       *(this->var) = orig;
     }
+    void reset()
+    {
+      *(this->var) = this->orig;
+    }
     ~LocalOption() {
       *(this->var) = this->orig;
     }

src/debugger.hpp

@@ -103,7 +103,7 @@ inline void debug_ast(AST_Node_Ptr node, std::string ind, Env* env)
     std::cerr << (selector->has_line_break() ? " [line-break]": " -");
     std::cerr << (selector->has_line_feed() ? " [line-feed]": " -");
     std::cerr << std::endl;
-    debug_ast(selector->schema(), "#{} ");
+    debug_ast(selector->schema(), ind + "#{} ");
 
     for(const Complex_Selector_Obj& i : selector->elements()) { debug_ast(i, ind + " ", env); }
 

src/eval.cpp

@@ -51,7 +51,8 @@ namespace Sass {
   : exp(exp),
     ctx(exp.ctx),
     force(false),
-    is_in_comment(false)
+    is_in_comment(false),
+    is_in_selector_schema(false)
   {
     bool_true = SASS_MEMORY_NEW(Boolean, "[NA]", true);
     bool_false = SASS_MEMORY_NEW(Boolean, "[NA]", false);
@@ -1757,7 +1758,10 @@ namespace Sass {
   Selector_List_Ptr Eval::operator()(Complex_Selector_Ptr s)
   {
     bool implicit_parent = !exp.old_at_root_without_rule;
-    return s->resolve_parent_refs(exp.selector_stack, implicit_parent);
+    if (is_in_selector_schema) exp.selector_stack.push_back(0);
+    Selector_List_Obj resolved = s->resolve_parent_refs(exp.selector_stack, implicit_parent);
+    if (is_in_selector_schema) exp.selector_stack.pop_back();
+    return resolved.detach();
   }
 
   // XXX: this is never hit via spec tests
@@ -1772,6 +1776,7 @@ namespace Sass {
 
   Selector_List_Ptr Eval::operator()(Selector_Schema_Ptr s)
   {
+    LOCAL_FLAG(is_in_selector_schema, true);
     // the parser will look for a brace to end the selector
     Expression_Obj sel = s->contents()->perform(this);
     std::string result_str(sel->to_string(ctx.c_options));
@@ -1781,6 +1786,7 @@ namespace Sass {
     // a selector schema may or may not connect to parent?
     bool chroot = s->connect_parent() == false;
     Selector_List_Obj sl = p.parse_selector_list(chroot);
+    flag_is_in_selector_schema.reset();
     return operator()(sl);
   }
 

src/eval.hpp

@@ -25,6 +25,7 @@ namespace Sass {
 
     bool force;
     bool is_in_comment;
+    bool is_in_selector_schema;
 
     Boolean_Obj bool_true;
     Boolean_Obj bool_false;