6 files changed, 101 insertions, 1 deletions
diff --git a/spec/ruby/core/array/shared/collect.rb b/spec/ruby/core/array/shared/collect.rb
index 8d75f7db9a..030302ced6 100644
--- a/spec/ruby/core/array/shared/collect.rb
+++ b/spec/ruby/core/array/shared/collect.rb
@@ -1,4 +1,5 @@
 require_relative '../../enumerable/shared/enumeratorized'
+require_relative '../shared/iterable_and_tolerating_size_increasing'
 
 describe :array_collect, shared: true do
   it "returns a copy of array with each element replaced by the value returned by block" do
@@ -46,6 +47,8 @@ describe :array_collect, shared: true do
     @object = [1, 2, 3, 4]
   end
   it_should_behave_like :enumeratorized_with_origin_size
+
+  it_should_behave_like :array_iterable_and_tolerating_size_increasing
 end
 
 describe :array_collect_b, shared: true do
@@ -102,8 +105,37 @@ describe :array_collect_b, shared: true do
     end
   end
 
+  it "does not truncate the array is the block raises an exception" do
+    a = [1, 2, 3]
+    begin
+      a.send(@method) { raise StandardError, 'Oops' }
+    rescue
+    end
+
+    a.should == [1, 2, 3]
+  end
+
+  it "only changes elements before error is raised, keeping the element which raised an error." do
+    a = [1, 2, 3, 4]
+    begin
+      a.send(@method) do |e|
+        case e
+        when 1 then -1
+        when 2 then -2
+        when 3 then raise StandardError, 'Oops'
+        else 0
+        end
+      end
+    rescue StandardError
+    end
+
+    a.should == [-1, -2, 3, 4]
+  end
+
   before :all do
     @object = [1, 2, 3, 4]
   end
   it_should_behave_like :enumeratorized_with_origin_size
+
+  it_should_behave_like :array_iterable_and_tolerating_size_increasing
 end
diff --git a/spec/ruby/core/array/shared/index.rb b/spec/ruby/core/array/shared/index.rb
index a9896554f2..a4a0adbab6 100644
--- a/spec/ruby/core/array/shared/index.rb
+++ b/spec/ruby/core/array/shared/index.rb
@@ -1,3 +1,5 @@
+require_relative '../shared/iterable_and_tolerating_size_increasing'
+
 describe :array_index, shared: true do
   it "returns the index of the first element == to object" do
     x = mock('3')
@@ -34,4 +36,6 @@ describe :array_index, shared: true do
       [].send(@method).should be_an_instance_of(Enumerator)
     end
   end
+
+  it_should_behave_like :array_iterable_and_tolerating_size_increasing
 end
diff --git a/spec/ruby/core/array/shared/intersection.rb b/spec/ruby/core/array/shared/intersection.rb
index 49849b08c2..0b4166ab63 100644
--- a/spec/ruby/core/array/shared/intersection.rb
+++ b/spec/ruby/core/array/shared/intersection.rb
@@ -11,7 +11,8 @@ describe :array_intersection, shared: true do
   end
 
   it "creates an array with elements in order they are first encountered" do
-    [ 1, 2, 3, 2, 5 ].send(@method, [ 5, 2, 3, 4 ]).should == [2, 3, 5]
+    [ 1, 2, 3, 2, 5, 6, 7, 8 ].send(@method, [ 5, 2, 3, 4 ]).should == [2, 3, 5] # array > other
+    [ 5, 2, 3, 4 ].send(@method, [ 1, 2, 3, 2, 5, 6, 7, 8 ]).should == [5, 2, 3] # array < other
   end
 
   it "does not modify the original Array" do
diff --git a/spec/ruby/core/array/shared/iterable_and_tolerating_size_increasing.rb b/spec/ruby/core/array/shared/iterable_and_tolerating_size_increasing.rb
new file mode 100644
index 0000000000..3e73bad44b
--- /dev/null
+++ b/spec/ruby/core/array/shared/iterable_and_tolerating_size_increasing.rb
@@ -0,0 +1,25 @@
+describe :array_iterable_and_tolerating_size_increasing, shared: true do
+  before do
+    @value_to_return ||= -> _ { nil }
+  end
+
+  it "tolerates increasing an array size during iteration" do
+    # The goal is to trigger potential reallocation of internal array storage, so we:
+    # - use elements of different types, starting with the less generic (Integer)
+    # - add reasonably big number of new elements (~ 100)
+    array = [1, 2, 3] # to test some methods we need several uniq elements
+    array_to_join = [:a, :b, :c] + (4..100).to_a
+
+    ScratchPad.record []
+    i = 0
+
+    array.send(@method) do |e|
+      ScratchPad << e
+      array << array_to_join[i] if i < array_to_join.size
+      i += 1
+      @value_to_return.call(e)
+    end
+
+    ScratchPad.recorded.should == [1, 2, 3] + array_to_join
+  end
+end
diff --git a/spec/ruby/core/array/shared/keep_if.rb b/spec/ruby/core/array/shared/keep_if.rb
index f26aff028c..43a047c0a7 100644
--- a/spec/ruby/core/array/shared/keep_if.rb
+++ b/spec/ruby/core/array/shared/keep_if.rb
@@ -1,4 +1,5 @@
 require_relative '../../enumerable/shared/enumeratorized'
+require_relative '../shared/iterable_and_tolerating_size_increasing'
 
 describe :keep_if, shared: true do
   it "deletes elements for which the block returns a false value" do
@@ -56,5 +57,39 @@ describe :keep_if, shared: true do
         -> { @frozen.send(@method) { false } }.should raise_error(FrozenError)
       end
     end
+
+    it "raises a FrozenError on a frozen array only during iteration if called without a block" do
+      enum = @frozen.send(@method)
+      -> { enum.each {} }.should raise_error(FrozenError)
+    end
+  end
+
+  it "does not truncate the array is the block raises an exception" do
+    a = [1, 2, 3]
+    begin
+      a.send(@method) { raise StandardError, 'Oops' }
+    rescue
+    end
+
+    a.should == [1, 2, 3]
   end
+
+  it "only changes elements before error is raised, keeping the element which raised an error." do
+    a = [1, 2, 3, 4]
+    begin
+      a.send(@method) do |e|
+        case e
+        when 2 then false
+        when 3 then raise StandardError, 'Oops'
+        else true
+        end
+      end
+    rescue StandardError
+    end
+
+    a.should == [1, 3, 4]
+  end
+
+  @value_to_return = -> _ { true }
+  it_should_behave_like :array_iterable_and_tolerating_size_increasing
 end
diff --git a/spec/ruby/core/array/shared/select.rb b/spec/ruby/core/array/shared/select.rb
index 09101e8ab5..9c2cbf76c4 100644
--- a/spec/ruby/core/array/shared/select.rb
+++ b/spec/ruby/core/array/shared/select.rb
@@ -2,11 +2,14 @@ require_relative '../../../spec_helper'
 require_relative '../fixtures/classes'
 require_relative '../shared/enumeratorize'
 require_relative '../shared/keep_if'
+require_relative '../shared/iterable_and_tolerating_size_increasing'
 require_relative '../../enumerable/shared/enumeratorized'
 
 describe :array_select, shared: true do
   it_should_behave_like :enumeratorize
 
+  it_should_behave_like :array_iterable_and_tolerating_size_increasing
+
   before :each do
     @object = [1,2,3]
   end