Fix problems with success_cmd on windows nvim.

[Nicholas42]

Applied changes as suggested by @yongrenjie in #2084

[yongrenjie]

I think, just to be safe, I should check what happens if &shell is different from the default, since that may affect how the command string is quoted... I'll do that when I can...

[Nicholas42]

Yes, that seems like a good idea. One could also think about a parameter en/disabling this since it seems to be very fragile and not that important (though, personally I like it very much).

[yongrenjie]

Yeah, sadly, adding

set shell=powershell
set shellcmdflag=-command

to init.vim gives this error

At line:1 char:13
+ "cmd /s /c "set max_print_line=2000 & latexmk -verbose -file-line-err ...
+             ~~~
Unexpected token 'set' in expression or statement.
At line:1 char:37
+ "cmd /s /c "set max_print_line=2000 & latexmk -verbose -file-line-err ...
+                                     ~
The ampersand (&) character is not allowed. The & operator is reserved for future use; wrap an ampersand in double 
quotation marks ("&") to pass it as part of a string.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : UnexpectedToken

But this ampersand is already part of the existing code, and wasn't introduced by this PR. So it's probably not our/your problem to fix. :-)

[yongrenjie]

And I just noticed :h vimtex-faq-windows says to not change &shell anyway, so I guess that's not really a problem.

[lervag]

Thanks for this, and for the discussion. As I'm not a Windows user, I really do depend on the contribution of others to help make VimTeX work well on Windows as well - it is much appreciated!

[lervag]

Please note I also made a simple adjustment; see here:

vimtex/autoload/vimtex/compiler/latexmk.vim

Lines 628 to 638 in c1e0246

	function! s:wrap_option_appendcmd(name, value) abort " {{{1
	" Note: On Linux, we use double quoted perl strings; these interpolate
	" variables. One should therefore NOT pass values that contain `$`.
	let l:win_cmd_sep = has('nvim') ? '^&' : '&'
	let l:common = printf('$%s = ($%s ? $%s', a:name, a:name, a:name)
	return has('win32')
	\ ? printf(' -e "%s . '' %s '' : '''') . ''%s''"',
	\ l:common, l:win_cmd_sep, a:value)
	\ : printf(' -e ''%s . " ; " : "") . "%s"''',
	\ l:common, a:value)
	endfunction

I believe this should still work and I think it is slightly more readable. I also believe the comment makes more sense now. Can you confirm?

[lervag]

Please note I also made a simple adjustment; see here:

vimtex/autoload/vimtex/compiler/latexmk.vim

Lines 628 to 638 in c1e0246

	function! s:wrap_option_appendcmd(name, value) abort " {{{1
	" Note: On Linux, we use double quoted perl strings; these interpolate
	" variables. One should therefore NOT pass values that contain `$`.
	let l:win_cmd_sep = has('nvim') ? '^&' : '&'
	let l:common = printf('$%s = ($%s ? $%s', a:name, a:name, a:name)
	return has('win32')
	\ ? printf(' -e "%s . '' %s '' : '''') . ''%s''"',
	\ l:common, l:win_cmd_sep, a:value)
	\ : printf(' -e ''%s . " ; " : "") . "%s"''',
	\ l:common, a:value)
	endfunction

I believe this should still work and I think it is slightly more readable. I also believe the comment makes more sense now. Can you confirm?