feat: escape filenames in cmdline

Closes #751

lua/blink/cmp/sources/cmdline/constants.lua

@@ -0,0 +1,40 @@
+return {
+  help_commands = {
+    'help',
+    'hel',
+    'he',
+    'h',
+  },
+  file_commands = {
+    'edit',
+    'e',
+    'read',
+    'r',
+    'write',
+    'w',
+    'saveas',
+    'sav',
+    'split',
+    'sp',
+    'vsplit',
+    'vs',
+    'tabedit',
+    'tabe',
+    'badd',
+    'bad',
+    'next',
+    'n',
+    'previous',
+    'prev',
+    'args',
+    'source',
+    'so',
+    'find',
+    'fin',
+    'diffsplit',
+    'diffs',
+    'diffpatch',
+    'diffp',
+    'make',
+  },
+}

lua/blink/cmp/sources/cmdline/init.lua

@@ -3,6 +3,7 @@
 -- License: MIT
 
 local async = require('blink.cmp.lib.async')
+local constants = require('blink.cmp.sources.cmdline.constants')
 
 --- @class blink.cmp.Source
 local cmdline = {}
@@ -37,12 +38,19 @@ function cmdline:get_completions(context, callback)
     .empty()
     :map(function()
       -- Special case for help where we read all the tags ourselves
-      if vim.tbl_contains({ 'h', 'he', 'hel', 'help' }, arguments[1] or '') then
+      if vim.tbl_contains(constants.help_commands, arguments[1] or '') then
         return require('blink.cmp.sources.cmdline.help').get_completions(current_arg_prefix)
       end
 
       local query = (text_before_argument .. current_arg_prefix):gsub([[\\]], [[\\\\]])
-      return vim.fn.getcompletion(query, 'cmdline')
+      local completions = vim.fn.getcompletion(query, 'cmdline')
+
+      -- Special case for files, escape special characters
+      if vim.tbl_contains(constants.file_commands, arguments[1] or '') then
+        completions = vim.tbl_map(function(completion) return vim.fn.fnameescape(completion) end, completions)
+      end
+
+      return completions
     end)
     :map(function(completions)
       local items = {}