rescue SystemStackError that comes from inspecting self-referencing Hashes and Arrays; fix #2461

mrblib/array.rb

@@ -84,13 +84,20 @@ class Array
     self
   end
 
+  def _inspect
+    return "[]" if self.size == 0
+    "["+self.map{|x|x.inspect}.join(", ")+"]"
+  end
   ##
-  # Private method for Array creation.
+  # Return the contents of this array as a string.
   #
   # ISO 15.2.12.5.31 (x)
   def inspect
-    return "[]" if self.size == 0
-    "["+self.map{|x|x.inspect}.join(", ")+"]"
+    begin
+      self._inspect
+    rescue SystemStackError
+      "[...]"
+    end
   end
   # ISO 15.2.12.5.32 (x)
   alias to_s inspect

mrblib/hash.rb

@@ -192,15 +192,23 @@ class Hash
     h
   end
 
+  # internal method for Hash inspection
+  def _inspect
+    return "{}" if self.size == 0
+    "{"+self.map {|k,v|
+      k._inspect + "=>" + v._inspect
+    }.join(", ")+"}"
+  end
   ##
   # Return the contents of this hash as a string. 
  #
   # ISO 15.2.13.4.30 (x)
   def inspect
-    return "{}" if self.size == 0
-    "{"+self.map {|k,v|
-      k.inspect + "=>" + v.inspect
-    }.join(", ")+"}"
+    begin
+      self._inspect
+    rescue SystemStackError
+      "{...}"
+    end
   end
   # ISO 15.2.13.4.31 (x)
   alias to_s inspect

mrblib/kernel.rb

@@ -39,6 +39,11 @@ module Kernel
     !(self =~ y)
   end
 
+  # internal method for inspect
+  def _inspect
+    self.inspect
+  end
+
   def to_enum(*a)
     raise NotImplementedError.new("fiber required for enumerator")
   end