bug#22234: 25.0.50; EWW doesn't display some links in GNU manuals

[Eli Zaretskii]

To reproduce:

  emacs -Q
  M-x eww RET 
https://sourceware.org/gdb/current/onlinedocs/gdb/Connecting.html#Connecting RET

Scroll down to the link that says "see set remote exec-file", with
"set remote exec-file" a hyper-link, and press RET on the link

Result: you get an empty page.
Expected: You should get this page:

  
https://sourceware.org/gdb/current/onlinedocs/gdb/Remote-Configuration.html#set%20remote%20exec-file

My crystal ball of a former Texinfo hacker says that the offending
link goes through a short HTML page that just redirects to another
page, and EWW somehow gets confused by that.  But that's just a guess.


In GNU Emacs 25.0.50.206 (i686-pc-mingw32)
 of 2015-12-24
Repository revision: d107eda498f94423d846b0e2f1be7facab417b2a
Windowing system distributor 'Microsoft Corp.', version 5.1.2600
Configured using:
 'configure --prefix=/d/usr --enable-checking=yes,glyphs --with-wide-int
 --with-modules 'CFLAGS=-O0 -gdwarf-4 -g3''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB
TOOLKIT_SCROLL_BARS MODULES

Important settings:
  value of $LANG: ENU
  locale-coding-system: cp1255

Major mode: eww

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Contacting host: sourceware.org:443
https://sourceware.org/gdb/current/onlinedocs/gdb/set-remote-exec_002dfile.html#set-remote-exec_002dfile
Contacting host: sourceware.org:443

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message dired rfc822 mml mml-sec
mm-decode mm-bodies mm-encode mailabbrev gmm-utils mailheader sendmail
gnutls network-stream nsm starttls url-http tls mail-parse rfc2231
rfc2047 rfc2045 ietf-drums url-gw url-cache url-auth eww mm-url gnus
gnus-ems nnheader mail-utils wid-edit url-queue url url-proxy
url-privacy url-expand url-methods url-history url-cookie url-domsuf
url-util url-parse auth-source cl-seq eieio byte-opt bytecomp
byte-compile cl-extra cconv eieio-core cl-macs gv gnus-util mm-util
help-fns help-mode easymenu mail-prsvr password-cache url-vars mailcap
shr dom cl-loaddefs cl-lib subr-x pcase browse-url format-spec time-date
mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel dos-w32 ls-lisp disp-table w32-win w32-vars
term/common-win tool-bar dnd fontset image regexp-opt fringe
tabulated-list newcomment elisp-mode lisp-mode prog-mode register page
menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core frame cl-generic cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms
cp51932 hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese charscript case-table epa-hook jka-cmpr-hook help
simple abbrev minibuffer cl-preloaded nadvice loaddefs button faces
cus-face macroexp files text-properties overlay sha1 md5 base64 format
env code-pages mule custom widget hashtable-print-readable backquote
w32notify w32 multi-tty make-network-process emacs)

Memory information:
((conses 16 130951 7808)
 (symbols 56 24086 0)
 (miscs 48 40 99)
 (strings 16 27476 5599)
 (string-bytes 1 751769)
 (vectors 16 15676)
 (vector-slots 8 457223 3748)
 (floats 8 206 61)
 (intervals 40 3601 53)
 (buffers 856 12))