Add a safe migration mode to the wiki migrator.

The safe migrate mode can be invoked by setting the
safe_migrate environment variable to 'true' on the command
line when running the task.

RAILS_ENV=production rake gitlab:wiki:migrate

lib/tasks/gitlab/migrate_wiki.rake

@@ -11,7 +11,13 @@ namespace :gitlab do
     # Notes:
     #  * The existing Wiki content will remain in your
     #    database in-tact.
-    desc "GITLAB | Migrate Wiki content from database to Gollum repositories."
+    #  * If the migration does not work the first time,
+    #    run the `RAILS_ENV=production rake gitlab:wiki:rollback`
+    #    command and then execute the migration again with
+    #    the safe_migrate=true environment variable:
+    #
+    #    `RAILS_ENV=production rake gitlab:wiki:migrate safe_migrate=true`
+    desc "GITLAB | Migrate Wiki content from database to Gollum repositories. Use the safe_migrate=true argument if initial migration fails."
     task :migrate => :environment do
       wiki_migrator = WikiToGollumMigrator.new
       wiki_migrator.migrate!

lib/wiki_to_gollum_migrator.rb

+# encoding: UTF-8
+
 class WikiToGollumMigrator
   attr_reader :projects
@@ -84,7 +86,7 @@ class WikiToGollumMigrator
       # and revision created so the correct User is shown in
       # the commit message.
       wiki = GollumWiki.new(project, revision.user)
-      wiki_page = wiki.find_page(page.slug)
+      wiki_page = wiki.find_page(page.title)
       attributes = extract_attributes_from_page(revision, project)
@@ -103,6 +105,10 @@ class WikiToGollumMigrator
                      .with_indifferent_access
                      .slice(:title, :content)
+    if ENV["safe_migrate"] == "true"
+      attributes[:title] = gollum_safe_title(attributes[:title])
+    end
+
     slug = page.slug
     # Change 'index' pages to 'home' pages to match Gollum standards
@@ -113,6 +119,10 @@ class WikiToGollumMigrator
     attributes
   end
+  def gollum_safe_title(title)
+    title.parameterize.titleize
+  end
+
   def home_already_exists?(project)
     project.wikis.where(slug: 'home').any? || project.wikis.where(slug: 'Home').any?
   end

spec/lib/wiki_to_gollum_migrator_spec.rb

+# encoding: UTF-8
+
 require "spec_helper"
 describe WikiToGollumMigrator do
@@ -137,6 +139,98 @@ describe WikiToGollumMigrator do
       end
     end
+    context "when migrating wiki's with extra whitespace in the title" do
+      before do
+        subject.rollback!
+        ENV['safe_migrate'] = 'true'
+        @project = @projects.last
+        @page = @project.wikis.new(title: "2012-06-16 ", content: "Page with funky title")
+        @page.slug = @page.title.parameterize
+        @page.user = @project.owner
+        @page.save!
+
+        create_revision(@page)
+
+        subject.migrate!
+      end
+
+      it "creates the wiki page correctly" do
+        wiki = GollumWiki.new(@project, nil)
+        page = wiki.find_page("2012 06 16")
+        page.should be_present
+        page.versions.count.should == 2
+      end
+    end
+
+    context "when migrating wiki's with slashes in the title" do
+      before do
+        subject.rollback!
+        ENV['safe_migrate'] = 'true'
+        @project = @projects.last
+        @page = @project.wikis.new(title: "Awesome 1337 /bin/badass ", content: "Page with funky title")
+        @page.slug = @page.title.parameterize
+        @page.user = @project.owner
+        @page.save!
+
+        create_revision(@page)
+
+        subject.migrate!
+      end
+
+      it "creates the wiki page correctly" do
+        wiki = GollumWiki.new(@project, nil)
+        page = wiki.find_page("Awesome 1337 Bin Badass")
+        page.should be_present
+        page.versions.count.should == 2
+      end
+    end
+
+    context "when migrating wiki's with non alphanumeric characters in the title" do
+      before do
+        subject.rollback!
+        ENV['safe_migrate'] = 'true'
+        @project = @projects.last
+        @page = @project.wikis.new(title: "Awes@me-1337 #!/bin/badass? ", content: "Page with funky title")
+        @page.slug = @page.title.parameterize
+        @page.user = @project.owner
+        @page.save!
+
+        create_revision(@page)
+
+        subject.migrate!
+      end
+
+      it "creates the wiki page correctly" do
+        wiki = GollumWiki.new(@project, nil)
+        page = wiki.find_page("Awes Me 1337 Bin Badass")
+        page.should be_present
+        page.versions.count.should == 2
+      end
+    end
+
+    context "when migrating wiki's with non-english characters in the title" do
+      before do
+        subject.rollback!
+        ENV['safe_migrate'] = 'true'
+        @project = @projects.last
+        @page = @project.wikis.new(title: "Mögliche Aufteilung", content: "Page with funky title")
+        @page.slug = @page.title.parameterize
+        @page.user = @project.owner
+        @page.save!
+
+        create_revision(@page)
+
+        subject.migrate!
+      end
+
+      it "creates the wiki page correctly" do
+        wiki = GollumWiki.new(@project, nil)
+        page = wiki.find_page("Mogliche Aufteilung")
+        page.should be_present
+        page.versions.count.should == 2
+      end
+    end
+
     context "changing wiki title from index to home" do
       before do
         @project = @projects.last