fix: searchcount exception on invalid search regex

[xVermillionx]

Hi there, I encountered an error message generated by vim.fn.searchcount in M.place_cursor_on_node function when having hijack_cursor option enabled.

I don't know if this fix is wanted or not, its just something that bothered me when using vim.fn.searchcount and I noticed it occurring when opening NvimTree.

Using pcall should fix the occurrence of the error message generated by vim.fn.searchcount as showing this error seems to be irrelevant to the M.place_cursor_on_node function:

E54: Unmatched (                                                                                                                                                    
Error detected while processing CursorMoved Autocommands for "NvimTree_*":                                                                                          
Error executing lua callback: Vim:E54: Unmatched (                                                                                                                  
stack traceback:                                                                                                                                                    
        [C]: in function 'searchcount'                                                                                                                              
        ...e/.local/share/nvim/lazy/nvim-tree.lua/lua/nvim-tree.lua:108: in function 'place_cursor_on_node'                                                         
        ...e/.local/share/nvim/lazy/nvim-tree.lua/lua/nvim-tree.lua:236: in function <...e/.local/share/nvim/lazy/nvim-tree.lua/lua/nvim-tree.lua:234>   

To reproduce I just search for ( in my neovim, then open nvim-tree.

1. /\v(
2. :NvimTreeOpen

[gegoune]

I don't get that error, only E54: Unmatched ( right after the search as one would expect.

[geril2207]

I can reproduce, this fix seems reasonable

[gegoune]

Doesn't wrapping in pcall just hide underlying issue? Perhaps more fundamental fix is needed instead?

[geril2207]

Idea with searchcount was taken from lualine, and they also use searchcount with pcall wrap https://github.com/nvim-lualine/lualine.nvim/blob/master/lua/lualine/components/searchcount.lua#L22

Perhaps more fundamental fix is needed instead?

I think the problem here is error which interrupts the default behaviour, but the behaviour is correct(if we hide the error), isn't it? Are you about adding info log or something like this or more complex changes?

[alex-courtis]

Idea with searchcount was taken from lualine, and they also use searchcount with pcall wrap https://github.com/nvim-lualine/lualine.nvim/blob/master/lua/lualine/components/searchcount.lua#L22

Looks like I made that change: nvim-lualine/lualine.nvim#1088

Doesn't wrapping in pcall just hide underlying issue? Perhaps more fundamental fix is needed instead?

I reckon this should be classed as a vim bug: the initial search throws the E54: Unmatched ( exception which is correct. Having vim.fn.searchcount throw an error instead of returning the "zero" dictionary goes against the documentation and adds no value.

[alex-courtis]

Works nicely for hijack_cursor:

• valid, no match
• valid, match
• invalid