Retour à un diff plus léger, qui risque moins les soucis de mémoire en production (car appel de diff système fork un process supplémentaire, qui double la mémoire utilisée)

Gemfile

@@ -67,7 +67,7 @@ gem 'email_validator'
 # Email address obfuscation
 gem 'actionview-encoded_mail_to'
 # To display a patched diff for event descriptions
-gem 'diffy'
+gem 'differ', github: 'genuitytech/differ', branch: 'add_patch_format'
 
 # A generic library to administrate the tool
 gem 'activeadmin', github: 'gregbell/active_admin'

Gemfile.lock

@@ -6,9 +6,16 @@ GIT
       jquery-rails
       rails (>= 3.2.2)
 
+GIT
+  remote: git://github.com/genuitytech/differ.git
+  revision: ff1a29ab2fa87620149e001d07aa48bef92de850
+  branch: add_patch_format
+  specs:
+    differ (0.1.2)
+
 GIT
   remote: git://github.com/gregbell/active_admin.git
-  revision: 8b6586c23a623b3281c136b057d856cc8fb5457e
+  revision: 944af76ace89f941a7baa92775854d2e1d0e6dba
   specs:
     activeadmin (1.0.0.pre)
       arbre (~> 1.0, >= 1.0.2)
@@ -96,7 +103,7 @@ GEM
     builder (3.2.2)
     celluloid (0.16.0)
       timers (~> 4.0.0)
-    chunky_png (1.3.2)
+    chunky_png (1.3.3)
     coderay (1.1.0)
     coffee-rails (4.1.0)
       coffee-script (>= 2.2.0)
@@ -128,7 +135,6 @@ GEM
       thread_safe (~> 0.1)
       warden (~> 1.2.3)
     devise-i18n (0.11.2)
-    diffy (3.0.7)
     docile (1.1.5)
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
@@ -193,7 +199,7 @@ GEM
     inherited_resources (1.4.1)
       has_scope (~> 0.6.0.rc)
       responders (~> 1.0.0.rc)
-    jbuilder (2.2.3)
+    jbuilder (2.2.4)
       activesupport (>= 3.0.0, < 5)
       multi_json (~> 1.2)
     jquery-rails (3.1.2)
@@ -304,7 +310,7 @@ GEM
     select2-rails (3.5.9.1)
       thor (~> 0.14)
     sexp_processor (4.4.4)
-    simple_calendar (1.1.5)
+    simple_calendar (1.1.6)
       rails (>= 3.0)
     simple_oauth (0.2.0)
     simplecov (0.9.1)
@@ -379,7 +385,7 @@ DEPENDENCIES
   compass-rails
   devise
   devise-i18n
-  diffy
+  differ!
   email_validator
   font-awesome-rails
   geocoder

app/views/moderation_mailer/update.text.haml

@@ -10,7 +10,7 @@
 - prev = render file: '/events/show'
 - @event = former
 
-= raw Diffy::Diff.new prev, new
+= Differ.diff(new, prev).format_as(:patch).gsub(/\[\d{1,2}m/, '')
 \
 - if @current_user
   = edit_moderation_url @event