lynx-dev lynx2.8.3dev.1

[dickey]

1999-06-11 (2.8.3dev.1)
(This is KW's patch, with minor corrections)
* Key handling changes:
  - Extended lynxkeycodes:  a bit flag is used to indicate that the lower bits
    of the value already are a lynxactioncode and need not be looked up again. 
    Reduces need for back and forth forward and reverse binding lookups;
    currently only used in some places.
  - Extended lynxkeycodes:  several (currently three) bit flags are used to
    indicate key modifiers.
  - Added some macros for manipulating and mapping of these codes, see
    especially LYKeymap.h, LKC_TO_LAC() etc.  Added some comments about the
    various kinds of codes.
  - Added several editaction codes and flags for setting key modifier on next
    key (i.e.  for declaring keys as prefix keys, for the purposes of line
    editing); for flagging a key for different action if same key is repeated;
    for exiting input field line editing and passing a specific lynxactioncode
    on; and for undoing 8-bit C1 -> 7-bit replacement transformation for some
    chars.  Added code to line-editor implementation to react to these new
    editactions.  Note that the mapping of lynxkeycode to lynxactioncode
    outside of line editing, i.e.  KEYMAP in lynx.cfg etc., ignores the
    modifiers.  The main loop just drops modifier flags or ignores the modified
    key; modifier flags cannot be used in lynx.cfg KEYMAP 'keystroke' values.
  - An ESC not recognized as part of an escape sequence can set the appropriate
    modifier flag in LYgetch(), except for SLANG which normally uses a
    different LYgetch() implementation.  Interpreting an ESC prefix as modifier
    is very useful for situations where a held-down Alt key (or some other key)
    is encoded this way:  linux console, kermit with emacs key mappings,
    possibly xterm with '*eightBitInput:  false'.  OTOH it doesn't work for all
    characters or in all situations.
  - Extended syntax recognized in .lynx-keymaps file (which is only used if
    compiling with USE_KEYMAPS defined, which in turn depends on slang and
    ncurses version):
    (a) Meta-foo can be used to map an escape sequence to a key + modifier.
    (b) LAC:foo can be used to map an escape sequence directly to a
        lynxactioncode (actually, to an extended lynxkeycode that
        encapsulates a lynxactioncode).
    See examples added to samples/lynx-keymaps.
  - Extended syntax of KEYMAP option, additional field can override line-editor
    behavior.  PASS documented in lynx.cfg.
  - Extended syntax that can be used for specifying key in KEYMAP, some of the
    forms allowed in .lynx-keymaps file are now additionally recognized, but
    only if compiling with USE_KEYMAPS defined.  Left undocumented in lynx.cfg
    (maybe subject to change).
  - New "Bash-like" Line Editor binding.  Adds several new emacs-like editing
    functions.  Adds tables for keys with modifiers (actually the same table is
    currently used for all modifiers, to save some space).  Most notably, ^X is
    a prefix key to set a modifier flag.  Keys with second function when
    pressed twice are ^E^E and ^K^K.  ESC is also recognized as setting a
    modifier flag, in case it gets through without been having been handled in
    LYgetch().  See new file keystrokes/bashlike_edit_help.html for more info. 
    The Bash-like Line Editor Bindings are only compiled in if compiled with
    -DEXP_ALT_BINDINGS / configured with --enable-alt-bindings (but not subject
    to a new macro).  Implementation code for the new emacs-like functions
    additionally ifdef'd with ENHANCED_LINEEDIT. 
  - Avoid dependency on DNARROW key binding when form field line-editing is
    ended with Enter or Return key.
  - Take setting of real_c/old_c into consideration after return from form
    field line-editing.  Previously there were some strange effects: 
    statusline messages would sometimes not appear when they should, the KEYMAP
    command would sometimes not work when invoked with ^Vk while in a form
    field.
  - Make NOCACHE ('x') work for TEXT_SUBMIT_TYPE form fields (i.e.  forms with
    a single text input field where Enter automatically submits).  Of course
    'x' has to be typed as ^Vx while line-editing the field (or NOCACHE mapped
    to a different key).  Similarly allow DOWNLOAD, and HEAD to work for such
    fields.  Try to ensure that all permission checks that apply to other form
    submissions are also done for TEXT_SUBMIT_TYPE fields, this wasn't the case
    before.
  - New key actions LPOS_PREV_LINK and LPOS_NEXT_LINK.  They are like PREV_LINK
    and NEXT_LINK, with the difference that, when moving to a form input or
    textarea line, the last column position (relative to the field) is
    remembered.  They are not mapped by default, but mentioned in lynx.cfg.
  - New key action DWIMHELP.  It should give some context-sensitive help. 
    Currentely the appropriate Line Editor Binding help page is shown if a form
    input field is selected, otherwise it defaults to the main HELP page.
  - New key action DWIMEDIT.  Revert meaning of EDIT back to previous meaning: 
    always edit document file, not textarea content.  DWIMEDIT acts like
    EDITTEXTAREA if the current link is a form textarea or input field and
    AUTOEXTEDIT was defined, and like EDIT otherwise.  Also added slightly
    different statusline message if form field external editiong cannot be done
    because editing is disabled:  it shouldn't refer to "The 'e'dit command".
  - Summary of reasonable ways to invoke external texarea editing (assuming
    that it is desired to keep the action of 'e' to edit files at least outside
    of input fields):
    1) KEYMAP 'e' to DWIMEDIT, invoke ^Ve.  (if AUTOEXTEDIT is defined,
       which is the case by default.)
    1a) KEYMAP <some other key> to DWIMEDIT, invoke ^V<some other key>.
    1b) KEYMAP <some other key> to EDITTEXTAREA, invoke ^V<some other key>.
    2) KEYMAP a key (function or control, not printable!) to EDITTEXTAREA
       or DWIMEDIT, using PASS in the KEYMAP line.
    2a) Find some key whose LineEdit binding is already LYE_FORM_PASS, and
        KEYMAP it to EDITTEXTAREA or DWIMEDIT.
    3) compile with EXP_ALT_BINDINGS defined (--enable-alt-bindings),
       select Bash-like Bindings,
       invoke ^E^E or ^X^E (or ESC ^E aka M-C-e), or
       invoke ^Xe (or ESC e aka M-e), or
    3a) compile with EXP_ALT_BINDINGS defined (--enable-alt-bindings),
        and without selecting Bash-like Bindings
        (invoke ESC ^E aka M-C-e or ESC e aka M-e).
    Bindings in parentheses under 3/3a may not work with slang unless a
    tweaked .lynx-keymaps file is used.
* Other changes related to textarea handling:
  - More appropriate message statusline message if GROWTEXTAREA or INSERTFILE
    cannot be done because a textarea is not selected:  it shouldn't refer to
    "external editor".
  - Check whether an editor is defined before trying to use it for textarea
    editing.  Generate message if spawning of external textarea editor failed.
  - Allow INSERTFILE only if file access is not restricted.
  - Enforce dotfiles restriction and "show dot files" setting for INSERTFILE.
* Mouse handling changes, mostly only if mouse support comes via ncurses:
  - Re-enabled changing link by clicking in area *near* a link (but not on the
    link text), but limit max.  distance to 2 character positions.
  - Make mouse popup menu disappear when it should, by applying the right magic
    touchline() in popup_choice().
  - Lots of small tweaks to remove glitches in mouse handling, among them:  No
    left scrolling of long input fields on entering with mouse.  Try to ensure
    statusline is updated after mouse menu.  Make menu actions work as
    expected.  Avoid acting on mouse events, especially invoking mouse menu, in
    wrong context (e.g.  while at a prompt), at least in many places.
  - Clicking on left or right border of mouse menu now only moves selection.
  - At right end of top/bottom line, where single click causes HISTORY action,
    double click now causes VLINKS action.
  - Allow to distinguish between submitting and just positioning into a
    TEXT_SUBMIT_TYPE input field.  Single click positions, double click
    submits, 'activate' from menu also submits.
  - When initializing ncurses mouse, call mousemask() with only those bits set
    that we may actually be interested in.
* Changes relevant for handling window size changes:
  - For ncurses, changed the way how mainloop() notifies the curses library
    about a window size change.  The approach taken previously, and still used
    if we are not using ncurses, has more overhead, can unnecessarily switch
    out of the alternative screen buffer (and back) under xterm, and didn't
    really make ncurses update the WINDOW structures for the new size in time.
  - Other tweaks for size change:  make sure curdoc.link is valid after
    refresh.
  - Detection of size changes in more situations:  tolerate EOF from GetChar in
    the (non-SLANG) LYgetch_for() in more cases if errno is EINTR, if this
    happens check for a size change and generate trace output.  Recognize
    KEY_RESIZE from ncurses, check for a size change and generate trace output
    when it occurs.
  - Added NONRESTARTING_SIGWINCH lynx.cfg option and -nonrestarting_sigwinch
    flag.  If set, lynx *may* react more immediately to window size changes
    when running under xterm or similar.  Whether this actually has an effect
    depends on the implementation of sigaction() and on the behavior of the
    curses (or similar) library when a read() (or other system call) is
    interrupted by signals.
    Depends on '#if HAVE_SIGACTION', which currently has to be defined by hand,
    for example by 'make SITE_DEFS="-DHAVE_SIGACTION"'.  The command line flag
    is only available on systems with HAVE_SIGACTION and SIGWINCH.
  - Tweaks so that lynx in an xterm can survive when the window size is made
    (probably temporarily) very small, for example 1x1.  Avoid display_page's
    work if it wouldn't be displayable anyway.  Make display_title handle very
    small screen widths, at least to the degree that it doesn't crash.
* Except for VMS or when DOSPATH is defined, set restore_sigpipe_for_children.
  Fixes Debian bug #33853, maybe not really a bug but let's be nice.
* Changes in HTTCP.c:
  - Added a CTRACE_FLUSH before creation of NSL_FORK child process.
  - Block certain signals during creation of NSL_FORK child process, if
    sigprocmask() and friends are available.  This should prevent a rare
    problem where sometimes the child process could be killed before it has a
    chance to modify its signal handlers, resulting in screen corruption, a
    seemingly hanging lynx, and/or other problems.  It is assumed that
    sigprocmask() etc.  are available if HAVE_SIGACTION is true.  It currently
    has to be defined by hand, for example by 'make
    SITE_LYDEFS="-DHAVE_SIGACTION"'.
  - Generate diagnostic messages for some failures of forked lookup.  Depends
    on HAVE_H_ERRNO.  In particular, try to detect whether the child process
    failed because of memory problems, and also fake a 'z' in that case to
    short-circuit a URL guessing cycle.
  - For most systems, generate more trace output for connection attempts, close
    to the actual connect() and select() calls to prevent clobbering errno. 
    See SOCKET_DEBUG_TRACE.  This should help diagnose some obscure
    system-dependent problems that have occasionally been reported.
* Added some missing stuff for color handling to forms Option Menu code.
* Printing to screen sometimes didn't show anything for short texts, if screen
  output was buffered (and ncurses makes stdout buffered).  Added another
  fflush(stdout) in send_file_to_screen().
* Some checks for specific URLs (helpfilepath, lynxlistfile, and lynxjumpfile)
  in LYGetFile.c were inappropriately case-insensitive for Unix.  The
  comparison is now case-sensitive except for VMS.  This may need tweaking for
  DOS and similar systems.
* Added additional LYNoRefererForThis check in getfile(), the one in mainloop()
  could be missed for TEXT_SUBMIT_TYPE form fields.  Also moved other check for
  whether to send Referer header earlier, and made it apply for URL types that
  might be proxied.
* LYAddVisitedLink tried to regard documents with the same address but a
  different title string as different documents, but this was coded wrong. 
  Removed ineffective comparison, but keep old title string if new title string
  is empty.
* Correct long-standing logic error in MAIL_SYSTEM_ERROR_LOGGING handling.
  Apparently not many people are using it...
* Fix for traversal code to put the right address into the TRAVERSE_REJECT_FILE
  if a request fails after popping a document from the history stack (this can
  only occur if a previous request for the same document had succeeded).  Also
  don't try to send mail in such a case if MAIL_SYSTEM_ERROR_LOGGING is on. 
  Also prevent possible history stack underflow if this occurs on return to the
  first document.
* According to lynx.cfg, error logging mail may be sent to ALERTMAIL if no
  document owner is known, but this was not implemented; now it is.  ALERTMAIL
  is used if it is defined non-empty in userdefs.h.  Of course normally it
  should be left undefined.
* Fix for traversal code to reject form fields a bit earlier.  This prevents
  unnecessary lookups as well as adding of an empty line to the
  TRAVERSE_REJECT_FILE for each form field encountered.
* Format -crawl output as was documented in CRAWL.announce:  with this switch,
  link numbering is always off by default (userdefs.h and lynx.cfg defaults und
  saved user preference are ignored) unless -number_links is given, and -crawl
  -traversal format is now consistent with -crawl -dump with respect to link
  numbering.  As a side effect, -crawl without either -traversal or -dump now
  also turns link numbering off unless -number_links is used (the meaning of
  -crawl without either of these was undocumented), so it then acts effectively
  as a (less powerful) negation of the -number_links switch.
* For -crawl -dump, the list of links was appended twice.  Fixed.
* Check URL as well as title before deciding that a document should not be
  pushed on the history stack because it looks like a generated special page.
* Made "Don't waste the cache" optimization in historytarget() subject to
  additional checks, to avoid uncaching of the wrong document in some cases.
* LYSafeGets() would drop the last line from a file if it was not terminated. 
  Changed to return the unterminated line like fgets().
* Clarifications on restrictions.  "download" does not imply "disk_save" while
  "print" does, this doesn't seem to make much sense but has been the behavior
  for a long time.
* Restrictions inside_news, outside_news now apply to reading as well as
  posting.  The documentation (except for the corresponding comments in
  userdefs.h) said that they apply to posting, while in fact they were
  implemented for reading only.  [Does nobody read this stuff???] Also, the
  implementation only checked the flag for news:  URLs, but not for nntp: 
  URLs, which doesn't make much sense given that the latter provide an
  alternative way for most (if not all) purposes of the first.  So now these
  restrictions apply to news:, nntp:, newspost:, and newsreply:  (but not to
  snews:, snewspost:, or snewsreply:).
* Document -restrictions=externals.
* Some of the restriction stuff not added to VMS lynx.hlp file, since I'm not
  quite sure whether the corresponding features work there at all.
* Changed restriction parsing so that "all" and "default" don't get ignored if
  they appear as one of several items in the same list.
* Implement listing of current restrictions to stdout with new -restrictions=? 
  option.  This should appear as the last command line option, otherwise the
  effect of options appearing later may not be shown.  The '?' may require
  quoting.
* Made -restrictions= (without any option flags) act like -restrictions
  (without equal sign either) as implied by documentation, i.e.  list
  recognized restriction options.
* LYRestricted has been greatly abused.  Once upon a time it was a PRIVATE flag
  in LYMain.c (then called anon_restrictions_set), used only to get the
  precedence of various command line options right.  Recently it has been
  misused as a check (and as the only one) whether "anonymous restrictions" are
  in effect.  This undermines various assumptions:
  - that -anonymous is basically an aggregate set of restrictions which could
    be specified individually with -restrictions=.
  - that individually listed restrictions (-restrictions=...) act as expected,
    and can be used to restrict various aspects in a useful manner.
  - that -validate implies the strongest restrictions, except for what is
    explicitly exempted (i.e. 'g'oto for http/https URLs).
  Use specific restrictions instead:
  - new "compileopts_info" for LYNXCOMPILEOPTS:  - for anonymous default see
    userdefs.h
  - new "lynxcfg_info" for LYNXCFG: - for anonymous default see userdefs.h
  - new "lynxcfg_xinfo" for extended LYNXCFG: - for anonymous default see
    userdefs.h
  - new invisible "goto_configinfo" for LYNXCOMPILEOPTS: & LYNXCFG: for
    anonymous default, see userdefs.h
  - additionally check existing "option_save" for LYNXCFG://reload/ -
    always restricted by anonymous default
  ("invisible" means that this restriction cannot be explicitly listed in a
  -restrictions=...  list, but has a value derived from userdefs.h that is used
  with -anonymous and -restrictions=default.)
* Forms options menu can now be used with -validate.
* Allow following local help file links, even if "file_url" restriction is set,
  from LYNXKEYMAP, LYNXCOOKIES.  (Possibly more need to be added.)
* Apparently realm checking (with -realm option) is bypassed for URLs from
  (some) form submissions (it seems to be intentional, but why?).  Made sure
  this at least doesn't weaken -validate restrictions.
* Apply -localhost check in getfile for news URLs that include a hostname,
  i.e., that begin with with "news://";.
* Add '&' to nonalphanumeric characters forbidden by exec_ok() for lynxexec and
  lynxprog URLs, but keep allowing it for lynxcgi.  There's not much point in
  excluding ';' and so on if '&' is acceptable!
* Tweaked LYNXMESSAGES:  handling slightly:  don't bypass normal getfile
  handling.
* Reset LYforce_no_cache flag in mainloop() after failed access, before popping
  the previous (or, actually, probably currently still displayed) document.
* Tweak for 'no data' handling:  it isn't always an error, but was sometimes
  treated as such.  It mostly doesn't make a difference, except for the message
  printed when the startfile cannot be accessed and for traversal and mail
  error logging.  This needs to be revised to apply for all protocols.
* Added new functionality for rules:  Redirect, UseProxy, various others.  See
  cernrules.txt in samples directory for details.
* Prevent crashes in HTNews.c with HEAD.
* Allow HEAD requests for proxied URLs (checking whether any applicable proxy
  begins with http:  or lynxcgi:), as far as this can be determined based on
  regular environment settings (i.e.  unaware of proxying by rules).
* Modified add_item_to_list() so that if the restriction flag is omitted from a
  DOWNLOADER/UPLOADER/EXTERNAL line in lynx.cfg, it is assumed FALSE.  This
  modifies the change of 1998-10-17 to be on the safer side, it is more
  consistent with how PRINTER lines or lines with the colon separator present
  but the flag value absent are handled, and it only makes a difference when a
  -restriction command line option or its equivalent is in effect anyway.
* Deal with unusual cases where telnet and similar protocols are proxied, or
  possibly changed to a different type of protocol by rules.  Normally such
  protocols should never be proxied, but there was no protection against it,
  and lynx could crash.  The approach now taken does not disallow it, but just
  tries to deal with the situation in a way that avoids crashing; it is
  conceivable that one may want to direct e.g.  telnet or rlogin URLs to a HTTP
  page that explains why theses types are not supported.  A similar problem
  that occurred when e.g.  telnet was forbidden by a rule is also dealt with.
* Protect start_curses calls in getfile against being executed if
  dump_output_immediately is in effect.  Maybe access to telnet, rlogin,
  lynxexec URLs should be completely disabled for this case; skipping the
  start_curses at least avoids being left with non-restored tty settings after
  the program exits, is someone attempts to use -dump or -source with such a
  URL (the -dump or -source flags is then effectively more or less ignored).
* Tweaks in fix_http_urls, renamed fix_httplike_urls.
* Moved LYStrerror from LYStrings.{h,c} to HTAlert.{h,c}, so that it can be
  used in HT*.c files without pulling in yet more LY*.h headers.
* Reset 'safe' flag in anchor on parsing "Safe: no" and "Safe: false" headers.
* The top makefile.in had some 'rm -rf' for whole directories $(helpdir) and
  $(docdir) in install targets that could potentially wipe out unrelated files;
  added checks to make sure the directories haven't been changed to something
  not lynx-specific (they are regarded as lynx-specific if the last component
  is lynx_help and lynx_doc, respectively).
* Various doc tweaks.
* Updated README.defines.  Other contributors should please add their stuff
  there, too.