Problem: Support for user commands is spread out. No good reason to make
user commands optional.
Solution: Move user command support to usercmd.c. Always enable the
user_commands feature.
Problem: Giving error messages is not flexible.
Solution: Add semsg(). Change argument from "char_u *" to "char *", also
for msg() and get rid of most MSG macros. (Ozaki Kiichi, closes
#3302) Also make emsg() accept a "char *" argument. Get rid of
an enormous number of type casts.
Problem: Tabline is not always redrawn when something that is used in
'tabline' changes.
Solution: Add ":redrawtabline" so that a plugin can at least cause the
redraw when needed.
Problem: :digraph output is not easy to read.
Solution: Add highlighting for :digraphs. (Marcin Szamotulski, closes#3572)
Also add section headers for :digraphs!.
Problem: It is not easy to edit a script that was sourced.
Solution: Add a count to ":scriptnames", so that ":script 40" edits the
script with script ID 40.
Problem: Defining function in sandbox is inconsistent, cannot use :function
but can define a lambda.
Solution: Allow defining a function in the sandbox, but also use the sandbox
when executing it. (closes#3182)
Problem: Cannot send lines to a terminal job.
Solution: Make [range]terminal send selected lines to the job.
Use ++rows and ++cols for the terminal size.
Problem: Problems with autocommands when opening help.
Solution: Avoid using invalid "varp" value. Allow using :wincmd if buffer
is locked. (closes#1806, closes#1804)
Problem: Cannot resize the window in a FileType autocommand. (Ingo Karkat)
Solution: Add the CMDWIN flag to :resize. (test by Ingo Karkat,
closes#1804)
Problem: It is not so easy to write a script that works with both Python 2
and Python 3, even when the Python code works with both.
Solution: Add 'pyxversion', :pyx, etc. (Marc Weber, Ken Takata)
Problem: ":lb" is interpreted as ":lbottom" while the documentation says it
means ":lbuffer".
Solution: Adjust the order of the commands. (haya14busa, closes#1093)
Problem: :filter does not work for many commands. Can only get matching
messages.
Solution: Make :filter work for :command, :map, :list, :number and :print.
Make ":filter!" show non-matching lines.
Problem: Adding pattern to ":oldfiles" is not a generic solution.
Solution: Add the ":filter /pat/ cmd" command modifier. Only works for some
commands right now.
Problem: It is not possible to only see part of the message history. It is
not possible to clear messages.
Solution: Add a count to ":messages" and a clear argument. (Yasuhiro
Matsumoto)
Problem: The Sniff interface is no longer useful, the tool has not been
available for may years.
Solution: Delete the Sniff interface and related code.
Problem: ":argadd" without argument is supposed to add the current buffer
name to the arglist.
Solution: Make it work as documented. (Coot, closes#577)
