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

3 files changed, 29 insertions, 9 deletions

diff --git a/mrblib/array.rb b/mrblib/array.rb
index 3218aa858..bd8d5930f 100644
--- a/mrblib/array.rb
+++ b/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
diff --git a/mrblib/hash.rb b/mrblib/hash.rb
index 9bb146b27..e7c51fb1f 100644
--- a/mrblib/hash.rb
+++ b/mrblib/hash.rb
@@ -192,16 +192,24 @@ class Hash
     h
   end
 
-  ##
-  # Return the contents of this hash as a string.
-  #
-  # ISO 15.2.13.4.30 (x)
-  def inspect
+  # internal method for Hash inspection
+  def _inspect
     return "{}" if self.size == 0
     "{"+self.map {|k,v|
-      k.inspect + "=>" + v.inspect
+      k._inspect + "=>" + v._inspect
     }.join(", ")+"}"
   end
+  ##
+  # Return the contents of this hash as a string. 
+ #
+  # ISO 15.2.13.4.30 (x)
+  def inspect
+    begin
+      self._inspect
+    rescue SystemStackError
+      "{...}"
+    end
+  end
   # ISO 15.2.13.4.31 (x)
   alias to_s inspect
 
diff --git a/mrblib/kernel.rb b/mrblib/kernel.rb
index d0fe47300..476ec8e18 100644
--- a/mrblib/kernel.rb
+++ b/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