Fix URL escape issues by escaping on URI parse error only

Fixes #2456, Closes #2457, Fixes #2472, Closes #2473, Fixes #2505, Fixes #2517, Closes #2518

lib/carrierwave/downloader/base.rb

@@ -31,7 +31,7 @@ def download(url, remote_headers = {})
       end
 
       ##
-      # Processes the given URL by parsing and escaping it. Public to allow overriding.
+      # Processes the given URL by parsing it, and escaping if necessary. Public to allow overriding.
       #
       # === Parameters
       #
@@ -40,8 +40,12 @@ def download(url, remote_headers = {})
       def process_uri(uri)
         uri_parts = uri.split('?')
         encoded_uri = Addressable::URI.parse(uri_parts.shift).normalize.to_s
-        encoded_uri << '?' << Addressable::URI.encode(uri_parts.join('?')).gsub('%5B', '[').gsub('%5D', ']') if uri_parts.any?
-        URI.parse(encoded_uri)
+        query = uri_parts.any? ? "?#{uri_parts.join('?')}" : ''
+        begin
+          URI.parse("#{encoded_uri}#{query}")
+        rescue URI::InvalidURIError
+          URI.parse("#{encoded_uri}#{URI::DEFAULT_PARSER.escape(query)}")
+        end
       rescue URI::InvalidURIError, Addressable::URI::InvalidURIError
         raise CarrierWave::DownloadError, "couldn't parse URL: #{uri}"
       end

spec/downloader/base_spec.rb

@@ -159,6 +159,20 @@
       expect(processed.to_s).to eq('http://example.com/%5D.jpg?test[]')
     end
 
+    it "escapes and parse unescaped characters in path" do
+      uri = 'http://example.com/あああ.jpg'
+      processed = subject.process_uri(uri)
+      expect(processed.class).to eq(URI::HTTP)
+      expect(processed.to_s).to eq('http://example.com/%E3%81%82%E3%81%82%E3%81%82.jpg')
+    end
+
+    it "escapes and parse unescaped characters in query string" do
+      uri = 'http://example.com/?q=あああ'
+      processed = subject.process_uri(uri)
+      expect(processed.class).to eq(URI::HTTP)
+      expect(processed.to_s).to eq('http://example.com/?q=%E3%81%82%E3%81%82%E3%81%82')
+    end
+
     it "throws an exception on bad uris" do
       uri = '~http:'
       expect { subject.process_uri(uri) }.to raise_error(CarrierWave::DownloadError)