Wrong Diazo transformation on Plone 5.2 Python 3.6

When having a diazo theme that includes the following rule:
<replace css:theme="#theme-div" css:content="#css-div" href="@@browser-view"/>
The unicode chars from that view are not showed correctly, i.e: á shows like: Ã

It only happens when the html from the view its include with the rule, if you visit /@@browser-view
all characters are showed correctly, also if the characters come from the content.

Has anybody experienced this error? Any hint how to solve it?

If you use this for injecting CSS, I do the same with themefragments (and it works).

   <replace css:theme="#custcss" css:content="#custcss"  href="/@@theme-fragment/customcss"  />

(the /customcss means that the template has content
with id=customcss

You should also be able to 'include browser views' from themefragments… probably something like this:

<tal:replace  tal:replace="structure context/@@myview"></tal:replace>

If someone encounters the same issue this is what I have found after debuging diazo, plone.app.theming, and plone.transformchain. Seems the problem it is related with the encoding.

The transformation returns a repoze.xmliter.serializer.XMLSerializer object.
For their elements a decode('utf-8') it's applied.
Modifying it by decode('utf-8').encode('latin-1').decode('utf-8') fixed it for me.

I have filled an issue on the repo:

Seems I was wrong, the fix isn't working, when trying to decode the bytes are already mixed encoded content.
I have filled another issue on plone.app.theming: https://github.com/plone/plone.app.theming/issues/162

This is a wild guess, but I have had a lot of unicode errors with different versions of 'theming related stuff'.
For example: I can not use the default pins of plone.app.mosaic.

Could you try this and see if it changes anything:

Well I have taken a look and plone.jsonserializer does not come by default (clean installation). It is pulled by plone.app.mosaic

Sorry for the confusing answer.

I was thinking: Is there something similar in some of the code.

When I ported some of my add-ons to 5.2 I think I saw similar (unicode) errors several places (If I remember right they came from the way things were checked with six

if isinstance(url, six.text_type):
if isinstance(url, six.binary_type):

I had the same problems with plone.subrequest ( I need to pin it to 1.8.6 to get mosaic to work without unicode errors.

I got this issue as well, any solution or workaround in sight?

What I did was modify: https://github.com/plone/plone.app.theming/blob/master/src/plone/app/theming/utils.py#L167
Adding the following code:

elif content_type == 'text/html':
    result = ''.join([
         '<meta charset="utf-8"/>',

Also you can move the code from browsers views to viewlets so you don't need to inject it with diazo

Thank you @csanahuja your modification works fine. I will also look into if there is any chance I don't need to inject and replace content with diazo.