Use the is_valid_subnum() function before using the smb.subnum as an index into (s)cfg.sub[]. Related to the previous committed fix of writemsg(): leaving the global smb.subnum as -1 (INVALID_SUB) after replying to a post via email or netmail, resulting in a crash here.

Fix issue introduced 9 years ago that could cause a crash after replying to a post via email or netmail and then displaying the header of a poll message or a normal message with votes:

Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007f9f9569a317 in sbbs_t::show_msg (this=0x7f9f70c56880,
    smb=0x7f9f70c5e4e0, msg=0x7f9ebadf08b0, p_mode=4, post=0x7f9f18071a24)
    at getmsg.cpp:255
255                                             ,cfg.sub[smb->subnum]->misc&SUB_                                                                              NAME ? useron.name : useron.alias, NET_NONE, NULL);
[Current thread is 1 (Thread 0x7f9ebadf3700 (LWP 23279))]
(gdb) print smb->subnum
$1 = 4294967295
(gdb) bt
#0  0x00007f9f9569a317 in sbbs_t::show_msg (this=0x7f9f70c56880,
    smb=0x7f9f70c5e4e0, msg=0x7f9ebadf08b0, p_mode=4, post=0x7f9f18071a24)
    at getmsg.cpp:255
#1  0x00007f9f957b2aee in sbbs_t::scanposts (this=0x7f9f70c56880, subnum=9,
    mode=2, find=0x7f9ebadf1270 "") at readmsgs.cpp:670
#2  0x00007f9f957bb75a in sbbs_t::scanallsubs (this=0x7f9f70c56880, mode=2)
    at scansubs.cpp:219
#3  0x00007f9f9568c948 in sbbs_t::exec_msg (this=0x7f9f70c56880,
    csi=0x7f9f70c64768) at execmsg.cpp:315
#4  0x00007f9f95683129 in sbbs_t::exec_function (this=0x7f9f70c56880,
    csi=0x7f9f70c64768) at execfunc.cpp:422
#5  0x00007f9f95679450 in sbbs_t::exec (this=0x7f9f70c56880,
    csi=0x7f9f70c64768) at exec.cpp:1199
#6  0x00007f9f9577d742 in node_thread (arg=0x7f9f70c56880) at main.cpp:4364

writemsg() was changing the global smb.subnum and when writing an email or netmail, that subnum value is -1 (since it's not a sub-board) and then later show_msg() is using the smb.subnum as a index into scfg.sub[] when determining if the current user already voted on the message being displayed and then: bang, crash, fall down, go boom.

Simply saving and restoring the smb.subnum when executing an external editor is all that was needed here. And this is the first use of the C++ "auto" keyword in Synchronet!

As described in issue #412, when using extended mouse coordinate (SGR) mode, the mouse button release sequence would be received by the BBS after the hotspot-activated menu option was executed and then that button release sequence possibly passed through to the a child script or program that didn't know how to handle or ignore it.

To resolve this, the BBS now ignores ("eats") the mouse button *press* sequence and only acts upon the mouse button *release* sequence. This is more aligned with how button-clicks work in mouse-control/GUI applications anyway.

As requested. This closes issue #416

Fixed a couple of undefined variable errors.

See merge request !192

Address potential FAQ (issue #415)

In the mouse debug log output. Potentially helpful in debugging mouse related issues when using the SGR mouse reporting mode.

1. Don't enable mouse support if the user's terminal is configured to not
   support it.

2. After calling bbs.receive_file() which displays a menu and uses sbbs's
   internal mouse support, which enables a different mouse reporting mode,
   disable the console.mouse_mode (sbbs's internal mouse support) before
   re-enabling the mouse support for the avatar_chooser's own custom mouse
   mode. Fix fixes issue #414 reported by Nelgin.

3. Fixed a typo in a message displayed to user if avatar upload failed.

With one of the new fields being 64-bit, this lib now requires the updated
File object that supports read/writing 64-bit binary integers too.

Fixes issue #413, at least the non-mouse related part. I was only
able to reproduce it by trying to use the "Edit your avatar" menu item
after choose "I don't want an avatar".

This "I don't want" menu item is weird however and reappears when
the user exits and reruns the chooser, so there's probably still
some improvements needed with this menu item.

The "Upload an avatar" menu item issue is likely totally unrelated.
Please don't combine unrelated issues in the same bug report.

Also, changed "new Object();" and related syntax to literal object definitions, and similar for arrays.

Bug introduced in commit 0d9111a5: iniSet* functions would write key/values to the end of the list when the root section (NULL) was specified, rather than the beginning of the list.
The root section always starts at the beginning of the list/file, so I'm not sure why section_start() was doing anything other than returning 0 for the root section. It's possible this now breaks iniSortSections() in some way, so that should be retested with a file with a root section and named sections.

HTTP Directory requests without a trailing slash would "work" (the directory
listing would be sent), but the links to files, since they're relative to the
current request location, would be incorrect (missing the directory's virtual
subdir). So send a 301 response if a client requets a directory without a
trailing slash.

DD file lister: Fix for assignment to undeclared variable in file description search

See merge request !191

Added "use strict"; to dd_lightbar_menu.js and some Digital Distortion mods& made some fixes

See merge request !190

DDMsgReader: Text search now ignores user scan configuration

See merge request !189

DDMsgReader: When doing a text search, it now ignores the user scan configuration for sub-boards, to ensure it will show any results of the text search.

attr_conv.js: Replaced Sync attr literals with hexadecimal version so that "use strict" can be used

See merge request !188

Solves problem of status output lines being interleved with console
output (e.g. from print()) after executing a script.

When using the "Access to Sub-directories" option for a library, the auto-created directories did not have their virtual sub-directory name set. Pretty sure this was introduced along with the http access to filebases after v3.19b.

Also, only de-dupe the sub-directory names based on the directory name and not the code/code-suffix for now. Next up: auto-gen unique internal code when needed.

By default, each file transfer directory's internal code suffix is
used as the source of the sub-directory of the virtual path used
to represent a file area in the FTP and Web servers. Now, a sysop
can change that source to either each directory's short name or
long name, if they prefer.

For MRO, because he asked (on DOVE-Net).

DDMsgReader refactor for sysop save to BBS machine & attachments.

See merge request !187

DDMsgReader Version 1.49 - Refactor: Simplified saving a message to BBS machine for sysop (as-is, less processing); removed attachment stuff for pre-Synchronet 3.17; moved hasSyncAttrCodes() to attr_conv.js because that's where it needs to be.

DDMsgReader: Improved display of ANSI messages via the use of the Graphic object

See merge request !186