fix: preview the correct man page section (#1076)

doc/telescope.txt

@@ -646,6 +646,10 @@ builtin.man_pages({opts})                                *builtin.man_pages()*
     Parameters: ~
         {opts} (table)  options to pass to the picker
 
+    Fields: ~
+        {sections} (table)  a list of sections to search, use `{ "ALL" }` to
+                            search in all sections
+
 
 builtin.reloader({opts})                                  *builtin.reloader()*
     Lists lua modules and reloads them on `<cr>`

lua/telescope/builtin/init.lua

@@ -244,6 +244,7 @@ builtin.help_tags = require("telescope.builtin.internal").help_tags
 
 --- Lists manpage entries, opens them in a help window on `<cr>`
 ---@param opts table: options to pass to the picker
+---@field sections table: a list of sections to search, use `{ "ALL" }` to search in all sections
 builtin.man_pages = require("telescope.builtin.internal").man_pages
 
 --- Lists lua modules and reloads them on `<cr>`

lua/telescope/previewers/buffer_previewer.lua

@@ -505,14 +505,14 @@ previewers.man = defaulter(function(opts)
   return previewers.new_buffer_previewer {
     title = "Man Preview",
     get_buffer_by_name = function(_, entry)
-      return entry.value
+      return entry.value .. "/" .. entry.section
     end,
 
     define_preview = function(self, entry, status)
       local win_width = vim.api.nvim_win_get_width(self.state.winid)
       putils.job_maker({ "man", entry.section, entry.value }, self.state.bufnr, {
         env = { ["PAGER"] = pager, ["MANWIDTH"] = win_width },
-        value = entry.value,
+        value = entry.value .. "/" .. entry.section,
         bufname = self.state.bufname,
       })
       putils.regex_highlighter(self.state.bufnr, "man")