1 files changed, 29 insertions, 12 deletions
diff --git a/activesupport/lib/active_support/core_ext/array/grouping.rb b/activesupport/lib/active_support/core_ext/array/grouping.rb
index 640e6e9328..87ae052eb0 100644
--- a/activesupport/lib/active_support/core_ext/array/grouping.rb
+++ b/activesupport/lib/active_support/core_ext/array/grouping.rb
@@ -18,6 +18,11 @@ class Array
   #   ["3", "4"]
   #   ["5"]
   def in_groups_of(number, fill_with = nil)
+    if number.to_i <= 0
+      raise ArgumentError,
+        "Group size must be a positive integer, was #{number.inspect}"
+    end
+
     if fill_with == false
       collection = self
     else
@@ -25,15 +30,13 @@ class Array
       # subtracting from number gives how many to add;
       # modulo number ensures we don't add group of just fill.
       padding = (number - size % number) % number
-      collection = dup.concat([fill_with] * padding)
+      collection = dup.concat(Array.new(padding, fill_with))
     end
 
     if block_given?
       collection.each_slice(number) { |slice| yield(slice) }
     else
-      groups = []
-      collection.each_slice(number) { |group| groups << group }
-      groups
+      collection.each_slice(number).to_a
     end
   end
 
@@ -55,7 +58,7 @@ class Array
   #   ["4", "5"]
   #   ["6", "7"]
   def in_groups(number, fill_with = nil)
-    # size / number gives minor group size;
+    # size.div number gives minor group size;
     # size % number gives how many objects need extra accommodation;
     # each group hold either division or division + 1 items.
     division = size.div number
@@ -85,14 +88,28 @@ class Array
   #
   #   [1, 2, 3, 4, 5].split(3)              # => [[1, 2], [4, 5]]
   #   (1..10).to_a.split { |i| i % 3 == 0 } # => [[1, 2], [4, 5], [7, 8], [10]]
-  def split(value = nil, &block)
-    inject([[]]) do |results, element|
-      if block && block.call(element) || value == element
-        results << []
-      else
-        results.last << element
-      end
+  def split(value = nil)
+    if block_given?
+      inject([[]]) do |results, element|
+        if yield(element)
+          results << []
+        else
+          results.last << element
+        end
 
+        results
+      end
+    else
+      results, arr = [[]], self.dup
+      until arr.empty?
+        if (idx = arr.index(value))
+          results.last.concat(arr.shift(idx))
+          arr.shift
+          results << []
+        else
+          results.last.concat(arr.shift(arr.size))
+        end
+      end
       results
     end
   end