icon entities cannot be unicode or Rsvg chokes

[walter]

_SVGLoader in icon.py processes entities in order to map Sugar icons into user colors. It then calls Rsvg to generate the icon SVG. All is well if the icon colors are type str, but if they are type unicode, Rsvg generates an error.

In the Comments class in Sugar Journal expandedentry.py icon colors are extracted from metadata using json.loads. This call (at least on F19) converts all strings to type unicode. Hence the comment icons are not rendering since they trigger the problem described above.

A simple fix is to convert the icon colors to str with encode('ascii', 'replace') after the call from json.loads. A more robust fix might be to test for unicode in icon.py.

I've prepared both patches. Which would be best?

[godiard]

This issue has already happen in other places, should be good solve it on icon.py

[walter]

Please review ​https://github.com/sugarlabs/sugar-toolkit-gtk3/pull/33

[dnarvaez]

Can you post the error please? I'd expect pygobject to autoconvert the string.

[dnarvaez]

Answering myself:

TypeError: Item 0: Must be number or single byte string, not unicode

[godiard]

The fix have sense, please push.

[dnarvaez]

(The reason pygobject is not taking unicode as it normally does is that this function is explicitly requiring an uint8 array, not a string)

[walter]

I've moved the conversion to where the entities are first mapped in icon.py. New PR coming in a few minutes.

[Walter Bender]

Ensure entity value is type str

There are times when the entity value passed in for substitution
is of type unicode. This causes Rsvg to fail when processing the
SVG. This patch checks for unicode and converts it to utf-8.

Fixes #4621

Changeset: ec5f064c10d902958eb49035b2c35f91a7055267