Added check for content type for remote files

lib/css_parser/parser.rb

@@ -604,6 +604,12 @@ def read_remote_file(uri) # :nodoc:
             end
           end
 
+          unless res.content_type == "text/css"
+            @redirect_count = nil
+            raise RemoteFileError.new(uri.to_s) if @options[:io_exceptions]
+            return '', nil
+          end
+
           case res['content-encoding']
             when 'gzip'
               io = Zlib::GzipReader.new(StringIO.new(res.body))
@@ -614,6 +620,7 @@ def read_remote_file(uri) # :nodoc:
           end
         end
 
+
         if charset
           if String.method_defined?(:encode)
             src.encode!('UTF-8', charset)

test/test_css_parser_loading.rb

@@ -207,4 +207,18 @@ def test_toggling_not_found_exceptions
 
     cp_without_exceptions.load_uri!("#{@uri_base}/no-exist.xyz")
   end
+
+  def test_invalid_content_type
+    cp_with_exceptions = Parser.new(:io_exceptions => true)
+
+    err = assert_raises RemoteFileError do
+      cp_with_exceptions.load_uri!("#{@uri_base}/LadylikeBB.otf")
+    end
+
+    assert_includes err.message, "#{@uri_base}/LadylikeBB.otf"
+
+    cp_without_exceptions = Parser.new(:io_exceptions => false)
+
+    cp_without_exceptions.load_uri!("#{@uri_base}/LadylikeBB.otf")
+  end
 end