gnus is hanging on cite-parse

[Pavel Zhukov]

Hello,

I have problem with gnus displaying some messages like described in [1]
In my case traceback looks like [2]. As a workaround I use cite regexp like 
(setq message-cite-prefix-regexp ">") but it's not a solution.
The problem occurs if I try to open this email 
https://lists.isc.org/pipermail/dhcp-users/2017-September/020820.html for 
example (and many many others). 

Can somebody point me out what's wrong with the citation/regexp and how to fix 
that? Or how to debug the issue further.

[1]  https://lists.gnu.org/archive/html/info-gnus-english/2017-01/msg00006.html

[2]
Debugger entered--Lisp error: (quit)
  looking-at("^\\(\\([  ]*\\(\\w\\|[_.]\\)+>+\\|[       ]*[]>|]\\)+\\)? *>>>>> 
+\"\\([^\"\n]+\\)\" +==")
  gnus-cite-parse()
  gnus-cite-parse-wrapper()
  gnus-cite-parse-maybe(nil t)
  gnus-dissect-cited-text()
  gnus-article-fill-cited-article(nil t)
  gnus-article-fill-cited-long-lines()
  gnus-treat-article(nil 1 1 "text/plain")
  gnus-display-mime()
  gnus-article-prepare-display()
  gnus-article-prepare(218 nil)
  gnus-summary-display-article(218 nil)
  gnus-summary-select-article(nil nil pseudo)
  gnus-summary-scroll-up(1)
  funcall-interactively(gnus-summary-scroll-up 1)
  call-interactively(gnus-summary-scroll-up nil nil)
  command-execute(gnus-summary-scroll-up)