Problem:
"set filetype=man" assumes the user wants :Man features, this does extra
stuff like renaming the buffer as "man://".
Solution:
- old entrypoint was ":set filetype=man", but this is too presumptuous #15487
- make the entrypoints more explicit:
1. when the ":Man" command is run
2. when a "man://" buffer is opened
- remove the tricky b:man_sect checks in ftplugin/man.vim and syntax/man.vim
- MANPAGER is supported via ":Man!", as documented.
fixes#15487
Remove syncolor.vim in favor of defining the default highlight groups
directly in `init_highlight`. This approach provides a number of
advantages:
1. The highlights are always defined, regardless of whether or not the
syntax regex engine is enabled.
2. Redundant sourcing of syntax files is eliminated (syncolor.vim was
often sourced multiple times based on how the user's colorscheme file
was written).
3. The syntax highlighting regex engine and the highlight groups
themselves are more fully decoupled.
4. Removal of the confusing `:syntax on` / `:syntax enable` dichotomy
(they now both do the same thing).
This approach also correctly solves a number of bugs related to
highlighting (#15176, #12573, #15205).
This fixes an issue (#12573) where colorscheme files are sourced twice
upon startup. This occurs when the startup script calls `:colorscheme`,
which sets the `g:colors_name` global variable. When syntax highlighting
is enabled in `syn_maybe_enable()` the `syntax.vim` script is sourced
which in turn sources `synload.vim`. This script checks to see if
`g:colors_name` is set and, if so, runs
exe "colors " . colors_name
This is done to ensure that highlight groups are defined before enabling
the syntax highlighting engine.
Instead, source syncolors.vim before the startup scripts which sets up
default highlights and only load the full syntax engine after
the startup scripts or when the user runs `:syntax on`. Add a guard
variable `did_syncolor` to prevent syncolor.vim from being sourced
twice and remove the line mentioned above from synload.vim so that
the colorscheme file is not re-sourced when the syntax engine is loaded.
Update runtime files.
cb80aa2d53
Omit runtime/doc/tabpage.txt.
Patch v8.2.1401 is not ported yet.
Port optwin.vim changes without gettext().
Patch v8.2.1544 is not ported yet.
