Rel. 6.4: Icons are showing UTF glyphs (uWSGI issue)

When looking into the Rel. 6.4, I found many icons missing or
replaced by weird UTF symbols.

A first clue came when trying to run the server in development
mode (directly with python). Then things worked correctly.

Another clue was found in the logfile. There were a bunch of these:

uwsgi_response_sendfile_do(): Resource temporarily unavailable
[core/writer.c line 655]
during GET /pgadmin/static/js/generated/fonts/Roboto-Regular..ttf

So, after checking my systems, and analyzing the whereabouts of the
sendfile() syscall, I finally looked into the uWSGI code, and, yes,
the code is, eh, fixable.
What they do is, basically, when sendfile() returns with zero bytes
sent and a "please try later" message (EAGAIN - which is legal and
can happen), they treat it as an error and cancel the request.

So, if somebody knows somebody who might know the right people: please
give it a push to get us this fixed.
Here is the patch:

--- proto/base.c.orig 2022-01-20 05:33:38.724357000 +0100
+++ proto/base.c 2022-01-20 05:34:15.747790000 +0100
@@ -306,7 +306,7 @@
}
return UWSGI_AGAIN;
}
- if (wlen < 0) {
+ if (wlen <= 0) {
if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINPROGRESS) {
return UWSGI_AGAIN;
}