https://github.com/pydot/pydot/pull/281
https://bugs.gentoo.org/830676

(rebased)

From 4ab2c033c0dd67cab87be9a9392c558359caf80c Mon Sep 17 00:00:00 2001
From: Anton Bolshakov <blshkv@users.noreply.github.com>
Date: Tue, 4 Jan 2022 16:05:51 +0800
Subject: [PATCH] Update dot_parser.py

https://github.com/pydot/pydot/issues/277
--- a/dot_parser.py
+++ b/dot_parser.py
@@ -439,6 +439,8 @@ def graph_definition():
 
         noncomma = "".join([c for c in printables if c != ","])
         alphastring_ = OneOrMore(CharsNotIn(noncomma + ' '))
+        # override pyparsing tightened whitespace-skipping logic
+        alphastring_.skipWhitespace = True
 
         def parse_html(s, loc, toks):
             return '<%s>' % ''.join(toks[0])