(MODULES-8603) Ignore .keep_* files

On Gentoo there's always a .keep_<package>-<slot> (e.g.,
.keep_cronbase-0) file inside the cron directory to ensure it's not
removed with rmdir. Since usernames are very unlikely to start with
.keep_, we can safely filter out these hidden files.

Author: ekohl

lib/puppet/provider/cron/crontab.rb

@@ -273,17 +273,27 @@ def user
                   '/var/spool/cron'
                 end
 
+  # Return the directory holding crontab files stored on the local system.
+  #
+  # @api private
+  def self.crontab_dir
+    CRONTAB_DIR
+  end
+
   # Yield the names of all crontab files stored on the local system.
   #
-  # @note Ignores files that are not writable for the puppet process.
+  # @note Ignores files that are not writable for the puppet process and hidden
+  #   files that start with .keep
   #
   # @api private
   def self.enumerate_crontabs
     Puppet.debug "looking for crontabs in #{CRONTAB_DIR}"
     return unless File.readable?(CRONTAB_DIR)
     Dir.foreach(CRONTAB_DIR) do |file|
-      path = "#{CRONTAB_DIR}/#{file}"
-      yield(file) if File.file?(path) && File.writable?(path)
+      path = File.join(CRONTAB_DIR, file)
+      # Gentoo creates .keep_PACKAGE-SLOT files to make sure the directory is not
+      # removed
+      yield(file) if File.file?(path) && File.writable?(path) && !file.start_with?('.keep_')
     end
   end
 

spec/unit/provider/cron/crontab_spec.rb

@@ -202,4 +202,43 @@ def compare_crontab_record(have, want)
       end
     end
   end
+
+  context '#enumerate_crontabs' do
+    before(:each) do
+      File.expects(:readable?).with(subject.crontab_dir).returns(true)
+      Dir.expects(:foreach).with(subject.crontab_dir).multiple_yields(*files)
+    end
+
+    context 'only a hidden file' do
+      let(:files) { ['.keep_cronbase-0'] }
+
+      before(:each) do
+        files.each do |filename|
+          path = File.join(subject.crontab_dir, filename)
+          File.expects(:file?).with(path).returns(true)
+          File.expects(:writable?).with(path).returns(true)
+        end
+      end
+
+      it 'ignores .keep_* files' do
+        expect { |b| described_class.enumerate_crontabs(&b) }.not_to yield_control
+      end
+    end
+
+    context 'multiple files' do
+      let(:files) { ['myuser', '.keep_cronbase-0'] }
+
+      before(:each) do
+        files.each do |filename|
+          path = File.join(subject.crontab_dir, filename)
+          File.expects(:file?).with(path).returns(true)
+          File.expects(:writable?).with(path).returns(true)
+        end
+      end
+
+      it 'ignores .keep_* files' do
+        expect { |b| described_class.enumerate_crontabs(&b) }.to yield_control.once
+      end
+    end
+  end
 end