fix completion error

[tzachar]

When Lazy commands are searched in command line mode, completion fails horribly (sometime crashing nvim entirely) when the partial string to complete contains non-escape characters.
For example, running :Lazy up[ results in a crash.

The fix is to instruct string.find to perform a literal search, treating the string to search not as a regular expression.

[folke]

Merged, but I didnt' have this issue?

[tzachar]

It was triggered from within nvim-cmp for me:

:Lazy up[                                                                                                                                                                     
Error executing vim.schedule lua callback: Vim:E5108: Error executing Lua function: ...cal/share/nvim/lazy/lazy.nvim/lua/lazy/view/commands.lua:116: malformed pattern (missin
g ']')                                                                                                                                                                        
stack traceback:                                                                                                                                                              
        [C]: in function 'find'                                                                                                                                               
        ...cal/share/nvim/lazy/lazy.nvim/lua/lazy/view/commands.lua:116: in function <...cal/share/nvim/lazy/lazy.nvim/lua/lazy/view/commands.lua:114>                        
        vim/shared.lua: in function <vim/shared.lua:0>                                                                                                                        
        [C]: in function 'getcompletion'                                                                                                                                      
        ...cal/share/nvim/lazy/cmp-cmdline/lua/cmp_cmdline/init.lua:124: in function 'exec'                                                                                   
        ...cal/share/nvim/lazy/cmp-cmdline/lua/cmp_cmdline/init.lua:175: in function 'complete'                                                                               
        ...achar/.local/share/nvim/lazy/nvim-cmp/lua/cmp/source.lua:334: in function 'complete'                                                                               
        ...tzachar/.local/share/nvim/lazy/nvim-cmp/lua/cmp/core.lua:289: in function 'complete'                                                                               
        ...tzachar/.local/share/nvim/lazy/nvim-cmp/lua/cmp/core.lua:169: in function 'autoindent'                                                                             
        ...tzachar/.local/share/nvim/lazy/nvim-cmp/lua/cmp/core.lua:161: in function 'on_change'                                                                              
        ...tzachar/.local/share/nvim/lazy/nvim-cmp/lua/cmp/init.lua:313: in function 'callback'                                                                               
        .../.local/share/nvim/lazy/nvim-cmp/lua/cmp/utils/async.lua:138: in function <.../.local/share/nvim/lazy/nvim-cmp/lua/cmp/utils/async.lua:136>                

[folke]

Odd, must be a bug in CMP cmdline then

[tzachar]

I don't think so.
The following also triggers the bug:

:echo getcompletion("Lazy up[", "cmdline")

results in

E5108: Error executing Lua function: ...cal/share/nvim/lazy/lazy.nvim/lua/lazy/view/commands.lua:116: malformed pattern (missing ']')                                         
stack traceback:                                                                                                                                                              
        [C]: in function 'find'                                                                                                                                               
        ...cal/share/nvim/lazy/lazy.nvim/lua/lazy/view/commands.lua:116: in function <...cal/share/nvim/lazy/lazy.nvim/lua/lazy/view/commands.lua:114>                        
        vim/shared.lua: in function <vim/shared.lua:0>