Modifying frozen objects will raise `FrozenError`.

`FrozenError` is a subclass of `RuntimeError` which used to be
raised.  [Ruby2.5]

2 files changed, 4 insertions, 4 deletions

diff --git a/mrbgems/mruby-string-ext/mrblib/string.rb b/mrbgems/mruby-string-ext/mrblib/string.rb
index cb36d9a48..0da84daed 100644
--- a/mrbgems/mruby-string-ext/mrblib/string.rb
+++ b/mrbgems/mruby-string-ext/mrblib/string.rb
@@ -95,7 +95,7 @@ class String
   #    "hello".lstrip!      #=> nil
   #
   def lstrip!
-    raise RuntimeError, "can't modify frozen String" if frozen?
+    raise FrozenError, "can't modify frozen String" if frozen?
     s = self.lstrip
     (s == self) ? nil : self.replace(s)
   end
@@ -125,7 +125,7 @@ class String
   #  <code>nil</code> if <i>str</i> was not altered.
   #
   def strip!
-    raise RuntimeError, "can't modify frozen String" if frozen?
+    raise FrozenError, "can't modify frozen String" if frozen?
     s = self.strip
     (s == self) ? nil : self.replace(s)
   end
@@ -199,7 +199,7 @@ class String
   #    string                  #=> "thsa sting"
   #
   def slice!(arg1, arg2=nil)
-    raise RuntimeError, "can't modify frozen String" if frozen?
+    raise FrozenError, "can't modify frozen String" if frozen?
     raise "wrong number of arguments (for 1..2)" if arg1.nil? && arg2.nil?
 
     if !arg1.nil? && !arg2.nil?
diff --git a/mrbgems/mruby-struct/src/struct.c b/mrbgems/mruby-struct/src/struct.c
index 8de4b6c52..adeb09bc1 100644
--- a/mrbgems/mruby-struct/src/struct.c
+++ b/mrbgems/mruby-struct/src/struct.c
@@ -89,7 +89,7 @@ static void
 mrb_struct_modify(mrb_state *mrb, mrb_value strct)
 {
   if (MRB_FROZEN_P(mrb_basic_ptr(strct))) {
-    mrb_raise(mrb, E_RUNTIME_ERROR, "can't modify frozen struct");
+    mrb_raise(mrb, E_FROZEN_ERROR, "can't modify frozen struct");
   }
 
   mrb_write_barrier(mrb, mrb_basic_ptr(strct));