TestRig exports invalid SVG

[PlanetEarthSoftware]

[1] Damn! Github made it look like my description was not entered as I added to the comment rather than uncommenting it.

• I have reproduced my issue using the latest version of ANTLR
• I have asked at stackoverflow
  Obviously a fault
• Responses from the above seem to indicate that my issue could be an ANTLR bug
  N/A
• I have done a search of the existing issues to make sure I'm not sending in a duplicate

Please include the following information:

• target information (Java, C++ ...)
  Java
  I am targeting .net, Javascript and Python but using the test rig which parses to Java.
• smallest possible grammar and code that reproduces the behavior [[behaviour]]
  Smaller example does not reproduce fault.
• description of the expected behavior [2] [[behaviour]] and actual behavior [[behaviour]]
  Pointers to suspicious code regions are also very welcome.

Run antlr on the attached grammar.
Xenon.g4.zip

antlr4 Xenon.g4

Complete the parser

javac *.java

Run the testrig

grun Xenon xenon -gui config.xenon

Export to SVG
The .svg is attached

Open the .svg in say Microsoft Edge.

This page contains the following errors:
error on line 196 at column 6: xmlParseEntityRef: no name
Below is a rendering of the page up to the first error.

[kaby76]

We don't know what your input is. Please provide an input string.

[neon12345]

The SVG implementation seems to be incomplete. (try GH-4521)

[GeneThomas]

config.xenon.zip