Merge pull request #1976 from mgreter/bugfix/issue_1971

Add fix for remove placeholders for support blocks

Author: mgreter

src/remove_placeholders.cpp

@@ -68,10 +68,10 @@ namespace Sass {
     }
 
     void Remove_Placeholders::operator()(Media_Block* m) {
-        Block* b = m->block();
-        for (size_t i = 0, L = b->length(); i < L; ++i) {
-            if ((*b)[i]) (*b)[i]->perform(this);
-        }
+        operator()(m->block());
+    }
+    void Remove_Placeholders::operator()(Supports_Block* m) {
+        operator()(m->block());
     }
 
     void Remove_Placeholders::operator()(At_Rule* a) {

src/remove_placeholders.hpp

@@ -27,6 +27,7 @@ namespace Sass {
         void operator()(Block*);
         void operator()(Ruleset*);
         void operator()(Media_Block*);
+        void operator()(Supports_Block*);
         void operator()(At_Rule*);
 
         template <typename U>