Merge pull request #1951 from xzyfer/fix/issue-1907

Fix regression with evaluating interpolations next to binary operands

Author: xzyfer

src/eval.cpp

@@ -504,22 +504,22 @@ namespace Sass {
     }
 
     // only the last item will be used to eval the binary expression
-    if (String_Schema* s_1 = dynamic_cast<String_Schema*>(b->left())) {
-      if (!s_1->is_right_interpolant()) {
-        ret_schema = SASS_MEMORY_NEW(ctx.mem, String_Schema, s_1->pstate());
+    if (String_Schema* s_l = dynamic_cast<String_Schema*>(b->left())) {
+      if (!s_l->has_interpolant() && (!s_l->is_right_interpolant())) {
+        ret_schema = SASS_MEMORY_NEW(ctx.mem, String_Schema, s_l->pstate());
         Binary_Expression* bin_ex = SASS_MEMORY_NEW(ctx.mem, Binary_Expression, b->pstate(),
-                                                    b->op(), s_1->last(), b->right());
+                                                    b->op(), s_l->last(), b->right());
         bin_ex->is_delayed(b->left()->is_delayed() || b->right()->is_delayed());
         // bin_ex->is_interpolant(b->left()->is_interpolant());
-        for (size_t i = 0; i < s_1->length() - 1; ++i) {
-          *ret_schema << s_1->at(i)->perform(this);
+        for (size_t i = 0; i < s_l->length() - 1; ++i) {
+          *ret_schema << s_l->at(i)->perform(this);
         }
         *ret_schema << bin_ex->perform(this);
         return ret_schema->perform(this);
       }
     }
     if (String_Schema* s_r = dynamic_cast<String_Schema*>(b->right())) {
-      if (!s_r->is_left_interpolant() || op_type == Sass_OP::DIV) {
+      if (!s_r->has_interpolant() && (!s_r->is_left_interpolant() || op_type == Sass_OP::DIV)) {
         ret_schema = SASS_MEMORY_NEW(ctx.mem, String_Schema, s_r->pstate());
         Binary_Expression* bin_ex = SASS_MEMORY_NEW(ctx.mem, Binary_Expression, b->pstate(),
                                                     b->op(), b->left(), s_r->first());
@@ -691,7 +691,7 @@ namespace Sass {
         }
       }
 
-    if (force_delay) {
+      if (force_delay) {
         std::string str("");
         str += v_l->to_string(ctx.c_options);
         if (b->op().ws_before) str += " ";