bug#37974: eww produces "error in process filter: Specified time is not representable"

[Stuart Little]

Apologies for the uninformative message below. I know slightly more now.

Setting debug-on-error and running

M-x eww RET arxiv.org RET

again produces the following trace:

--- cut here ---

Debugger entered--Lisp error: (error "Specified time is not representable")     
                                                                               
  format-time-string("%a %b %d %H:%M:%S %Y GMT" (38427 52290 103040 624000) t)
  url-cookie-handle-set-cookie("browser=68.133.6.220.1572324160979722; path=/; 
max-age=946080000; domain=.arxiv.org")
  url-http-handle-cookies()
  url-http-parse-headers()
  url-http-chunked-encoding-after-change-function(7029 7034 5)
  url-http-generic-filter(#<process arxiv.org<1>> "0\015\n\015\n")
  read-event(nil t 2)
  sit-for(2)
  execute-extended-command(nil "eww" "eww")
  funcall-interactively(execute-extended-command nil "eww" "eww")
  call-interactively(execute-extended-command nil nil)
  command-execute(execute-extended-command)

--- done ---

This told me the problem was with the url-cookie-handle-set-cookie function; 
specifically, with the format-time-string directive therein. I tried to fiddle 
with it to confirm. Indeed, replacing the relevant if-then-else clause

--- cut ---

(if (and max-age (string-match "\\`-?[0-9]+\\'" max-age))                       
                                                                          
       (setq expires (format-time-string "%a %b %d %H:%M:%S %Y GMT"             
                                                                              
                                         (time-add nil (read max-age))          
                                                                              
                                         t))                                    
                                                                              
      (setq expires (cdr-safe (assoc-string "expires" args t))))

--- done ---

therein with just the else branch

(setq expires (cdr-safe (assoc-string "expires" args t)))

resolves the issue. arxiv.org loads fine with the redefined 
url-cookie-handle-set-cookie function. 

On Mon, Oct 28, 2019 at 08:32:45PM -0400, Stuart Little wrote:
> I am on a Debian 10.1 machine i686. The current Emacs version in this Debian 
> repo is 26.1.
> 
> My issue is that
> 
> M-x eww RET arxiv.org RET
> 
> fails to load the page and produces the error
> 
> error in process filter: Specified time is not representable
> 
> in the minibuffer. Other websites load fine (e.g. nytimes.com, 
> theguardian.comn, google.com). Others, on the other hand, simply silently 
> time out: duckduckgo.com and thenation.com behave this way (the minibuffer 
> reports 'contacting host' but the page never loads).
> 
> Everything loads fine on an Arch Linux x86_64 machine running Emacs 26.3 as 
> well as an Android 9 phone running an ARM version of Emacs 26.3 in a terminal 
> emulator (Termux), so it is not a network issue.
> 
> Additionally, a separate machine running Linux Mint 19.2 an Emacs 25.2.2 
> loads arxiv.org without issue.