Bad initialization: "set conceallevel"

[lervag]

Loading syntax/json.vim currently loads ftplugin/json.vim, which sets conceallevel. This is IMHO bad practise. For instance, if you load nested syntax in Markdown, LaTeX or similar, it should not affect the current filetype settings.

I noticed this:

vim-json/syntax/json.vim

Lines 6 to 8 in 3727f08

	" Reload the definition of g:vim_json_syntax_conceal
	" see https://github.com/elzr/vim-json/issues/42
	runtime! ftplugin/json.vim

Thus, #42 concluded that runtime! ftplugin/json.vim is necessary, but I propose it is not. Instead, you should replace the use of the option g:vim_json_syntax_conceal with get(g:, 'vim_json_syntax_conceal', 1) (or 0, if that's the default). Or, use a plugin/json.vim to set default values for the options. Or an autoload function. Whatever, but don't load ftplugin/json.vim.

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I notice that the repo seems relatively unmaintained, but I hope it might be possible to fix this regardless.

[pjfalbe]

I'm looking to try this module. What did you put in your .vimrc to load this plugin?

[nfischer]

I ran into this same issue today. I sent PR #108 to hopefully fix this properly, which guards with exists() expressions based on how vim's builtin json plugin works:

https://github.com/vim/vim/blob/5f1b115afd92544ce64d563da0d8ee9844abb10a/runtime/syntax/json.vim#L34

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In case the PR doesn't merge, here are some workarounds I figured out today:

1. In my case, the bug only repros if I have let g:markdown_fenced_languages = [ 'json', ... ] in my vimrc. Removing json from the list fixes the issue and lets markdown files render properly again. json files will still have conceallevel=2, as configured by the ftplugin script in this plugin.
2. If you can't live without g:markdown_fenced_languages, then an autocmd seems to also do the trick: autocmd BufNewfile,BufReadPost *.md setlocal conceallevel=0
3. If that doesn't work, you can explicitly set let g:vim_json_syntax_conceal = 0 but then you won't get concealing in json files anymore.