1 files changed, 19 insertions, 2 deletions
diff --git a/spec/ruby/core/string/shared/slice.rb b/spec/ruby/core/string/shared/slice.rb
index 3ef4bc50d7..7b9b9f6a14 100644
--- a/spec/ruby/core/string/shared/slice.rb
+++ b/spec/ruby/core/string/shared/slice.rb
@@ -84,8 +84,8 @@ describe :string_slice_index_length, shared: true do
     s = "hello there"
     s.send(@method, 1, 9).encoding.should == s.encoding
 
-    a = "hello".force_encoding("binary")
-    b = " there".force_encoding("ISO-8859-1")
+    a = "hello".dup.force_encoding("binary")
+    b = " there".dup.force_encoding("ISO-8859-1")
     c = (a + b).force_encoding(Encoding::US_ASCII)
 
     c.send(@method, 0, 5).encoding.should == Encoding::US_ASCII
@@ -119,6 +119,18 @@ describe :string_slice_index_length, shared: true do
     "hello there".send(@method, -4,-3).should == nil
   end
 
+  platform_is pointer_size: 64 do
+    it "returns nil if the length is negative big value" do
+      "hello there".send(@method, 4, -(1 << 31)).should == nil
+
+      # by some reason length < -(1 << 31) on CI on Windows leads to
+      # 'RangeError: bignum too big to convert into `long'' error
+      platform_is_not :windows do
+        "hello there".send(@method, 4, -(1 << 63)).should == nil
+      end
+    end
+  end
+
   it "calls to_int on the given index and the given length" do
     "hello".send(@method, 0.5, 1).should == "h"
     "hello".send(@method, 0.5, 2.5).should == "he"
@@ -152,6 +164,11 @@ describe :string_slice_index_length, shared: true do
     -> { "hello".send(@method, 0, bignum_value) }.should raise_error(RangeError)
   end
 
+  it "raises a RangeError if the index or length is too small" do
+    -> { "hello".send(@method, -bignum_value, 1) }.should raise_error(RangeError)
+    -> { "hello".send(@method, 0, -bignum_value) }.should raise_error(RangeError)
+  end
+
   it "returns String instances" do
     s = StringSpecs::MyString.new("hello")
     s.send(@method, 0,0).should be_an_instance_of(String)