Revert "Implement Ruby2.7's frozen strings from `Symbol#to_s`"

This feature was reverted from Ruby 2.7.

2 files changed, 9 insertions, 5 deletions

diff --git a/mrbgems/mruby-class-ext/src/class.c b/mrbgems/mruby-class-ext/src/class.c
index 0d27c30ed..02ebf80cc 100644
--- a/mrbgems/mruby-class-ext/src/class.c
+++ b/mrbgems/mruby-class-ext/src/class.c
@@ -5,7 +5,11 @@
 static mrb_value
 mrb_mod_name(mrb_state *mrb, mrb_value self)
 {
-  return mrb_class_path(mrb, mrb_class_ptr(self));
+  mrb_value name =  mrb_class_path(mrb, mrb_class_ptr(self));
+  if (mrb_string_p(name)) {
+    MRB_SET_FROZEN_FLAG(mrb_basic_ptr(name));
+  }
+  return name;
 }
 
 static mrb_value
diff --git a/mrbgems/mruby-symbol-ext/mrblib/symbol.rb b/mrbgems/mruby-symbol-ext/mrblib/symbol.rb
index 4b4cf83fe..99fa275d5 100644
--- a/mrbgems/mruby-symbol-ext/mrblib/symbol.rb
+++ b/mrbgems/mruby-symbol-ext/mrblib/symbol.rb
@@ -10,7 +10,7 @@ class Symbol
   # Same as <code>sym.to_s.capitalize.intern</code>.
 
   def capitalize
-    self.to_s.capitalize.to_sym
+    (self.to_s.capitalize! || self).to_sym
   end
 
   ##
@@ -20,7 +20,7 @@ class Symbol
   # Same as <code>sym.to_s.downcase.intern</code>.
 
   def downcase
-    self.to_s.downcase.to_sym
+    (self.to_s.downcase! || self).to_sym
   end
 
   ##
@@ -30,7 +30,7 @@ class Symbol
   # Same as <code>sym.to_s.upcase.intern</code>.
 
   def upcase
-    self.to_s.upcase.to_sym
+    (self.to_s.upcase! || self).to_sym
   end
 
   ##
@@ -41,7 +41,7 @@ class Symbol
 
   def casecmp(other)
     return nil unless other.kind_of?(Symbol)
-    lhs =  self.to_s.upcase
+    lhs =  self.to_s; lhs.upcase!
     rhs = other.to_s.upcase
     lhs <=> rhs
   end