Allow commandline args like 'xc:black'

lib/paperclip/command_line.rb

@@ -52,7 +52,7 @@ module Paperclip
           raise PaperclipCommandLineError,
             "Interpolation of #{key} isn't allowed."
         end
-        shell_quote(vars[key.to_sym])
+        interpolation(vars, key) || match
       end
     end
 
@@ -60,6 +60,12 @@ module Paperclip
       %w(expected_outcodes swallow_stderr)
     end
 
+    def interpolation(vars, key)
+      if vars.key?(key.to_sym)
+        shell_quote(vars[key.to_sym])
+      end
+    end
+
     def shell_quote(string)
       return "" if string.nil? or string.blank?
       if self.class.unix?

test/command_line_test.rb

@@ -6,6 +6,11 @@ class CommandLineTest < Test::Unit::TestCase
     File.stubs(:exist?).with("/dev/null").returns(true)
   end
 
+  should "allow colons in parameters" do
+    cmd = Paperclip::CommandLine.new("convert", "'a.jpg' -resize 175x220> -size 175x220 xc:black +swap -gravity center -composite 'b.jpg'", :swallow_stderr => false)
+    assert_equal "convert 'a.jpg' -resize 175x220> -size 175x220 xc:black +swap -gravity center -composite 'b.jpg'", cmd.command 
+  end
+
   should "take a command and parameters and produce a shell command for bash" do
     cmd = Paperclip::CommandLine.new("convert", "a.jpg b.png", :swallow_stderr => false)
     assert_equal "convert a.jpg b.png", cmd.command