feat(pickers): allow the scrolling limit to be configured

Promote the "temp__scrolling_limit" option into an officially supported
configuration field that controls the number of results displayed by pickers.

Closes: #2779

Author: davvid

lua/telescope/pickers.lua

@@ -324,7 +324,7 @@ function Picker:new(opts)
 
     cache_picker = config.resolve_table_opts(opts.cache_picker, vim.deepcopy(config.values.cache_picker)),
 
-    __scrolling_limit = tonumber(vim.F.if_nil(opts.temp__scrolling_limit, 250)),
+    scrolling_limit = tonumber(vim.F.if_nil(opts.scrolling_limit, 250)),
 
     __locations_input = vim.F.if_nil(opts.__locations_input, false),
   }, self)
@@ -571,11 +571,8 @@ function Picker:find()
   vim.fn.prompt_setprompt(self.prompt_bufnr, prompt_prefix)
   self:_reset_prefix_color()
 
-  -- TODO: This could be configurable in the future, but I don't know why you would
-  -- want to scroll through more than 10,000 items.
-  --
   -- This just lets us stop doing stuff after tons of  things.
-  self.max_results = self.__scrolling_limit
+  self.max_results = self.scrolling_limit
 
   vim.api.nvim_buf_set_lines(self.results_bufnr, 0, self.max_results, false, utils.repeated_table(self.max_results, ""))
 

lua/tests/automated/pickers/live_grep_spec.lua

@@ -35,7 +35,7 @@ describe("builtin.live_grep", function()
             sorter = require("telescope.sorters").get_fzy_sorter(),
             layout_strategy = "center",
             cwd = "./lua/tests/fixtures/live_grep",
-            temp__scrolling_limit = 5,
+            scrolling_limit = 5,
           }, vim.json.decode [==[%s]==])
         )
         ]],