1 files changed, 13 insertions, 6 deletions
diff --git a/activesupport/lib/active_support/cache/mem_cache_store.rb b/activesupport/lib/active_support/cache/mem_cache_store.rb
index e09cee3335..df8bc8e43e 100644
--- a/activesupport/lib/active_support/cache/mem_cache_store.rb
+++ b/activesupport/lib/active_support/cache/mem_cache_store.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 begin
   require "dalli"
 rescue LoadError => e
@@ -5,14 +7,13 @@ rescue LoadError => e
   raise e
 end
 
-require "digest/md5"
 require "active_support/core_ext/marshal"
 require "active_support/core_ext/array/extract_options"
 
 module ActiveSupport
   module Cache
     # A cache store implementation which stores data in Memcached:
-    # http://memcached.org/
+    # https://memcached.org
     #
     # This is currently the most popular cache store for production websites.
     #
@@ -97,12 +98,18 @@ module ActiveSupport
         options = merged_options(options)
 
         keys_to_names = Hash[names.map { |name| [normalize_key(name, options), name] }]
+
         raw_values = @data.get_multi(keys_to_names.keys)
         values = {}
+
         raw_values.each do |key, value|
           entry = deserialize_entry(value)
-          values[keys_to_names[key]] = entry.value unless entry.expired?
+
+          unless entry.expired? || entry.mismatched?(normalize_version(keys_to_names[key], options))
+            values[keys_to_names[key]] = entry.value
+          end
         end
+
         values
       end
 
@@ -114,7 +121,7 @@ module ActiveSupport
         options = merged_options(options)
         instrument(:increment, name, amount: amount) do
           rescue_error_with nil do
-            @data.incr(normalize_key(name, options), amount)
+            @data.incr(normalize_key(name, options), amount, options[:expires_in])
           end
         end
       end
@@ -127,7 +134,7 @@ module ActiveSupport
         options = merged_options(options)
         instrument(:decrement, name, amount: amount) do
           rescue_error_with nil do
-            @data.decr(normalize_key(name, options), amount)
+            @data.decr(normalize_key(name, options), amount, options[:expires_in])
           end
         end
       end
@@ -175,7 +182,7 @@ module ActiveSupport
           key = super.dup
           key = key.force_encoding(Encoding::ASCII_8BIT)
           key = key.gsub(ESCAPE_KEY_CHARS) { |match| "%#{match.getbyte(0).to_s(16).upcase}" }
-          key = "#{key[0, 213]}:md5:#{Digest::MD5.hexdigest(key)}" if key.size > 250
+          key = "#{key[0, 213]}:md5:#{ActiveSupport::Digest.hexdigest(key)}" if key.size > 250
           key
         end