fix: previewer if cwd is not curr dir (#2084)

path needs to be expanded for filereadable and isdirectory

(cherry picked from commit 8746347)

lua/telescope/from_entry.lua

@@ -25,9 +25,15 @@ function from_entry.path(entry, validate, escape)
   end
 
   -- only 0 if neither filereadable nor directory
-  local invalid = vim.fn.filereadable(path) + vim.fn.isdirectory(path)
-  if validate and invalid == 0 then
-    return
+  if validate then
+    -- We need to expand for filereadable and isdirectory
+    -- TODO(conni2461): we are not going to return the expanded path because
+    --                  this would lead to cache misses in the perviewer.
+    --                  Requires overall refactoring in previewer interface
+    local expanded = vim.fn.expand(path)
+    if (vim.fn.filereadable(expanded) + vim.fn.isdirectory(expanded)) == 0 then
+      return
+    end
   end
   if escape then
     return vim.fn.fnameescape(path)