Leave archive before searching for project root

When TRAMP archives are enabled, back out of the archive before trying to find
the project root. Starting inside the archive makes opening archives quite slow.

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## master (unreleased)
 
 * [#1497](https://github.com/bbatsov/projectile/pull/1497)] New command `projectile-run-gdb` (<kbd>x g</kbd> in `projectile-command-map`).
+* [#1503](https://github.com/bbatsov/projectile/pull/1503)] Leave archive before searching for the project root.
 
 ## 2.1.0 (2020-02-04)
 

projectile.el

@@ -1077,6 +1077,11 @@ If DIR is not supplied its set to the current directory by default."
   ;; cl-subst to replace this 'none value with nil so a nil value is used
   ;; instead
   (let ((dir (or dir default-directory)))
+    ;; Back out of any archives, the project will live on the outside and
+    ;; searching them is slow.
+    (when (and (fboundp 'tramp-archive-file-name-archive)
+               (tramp-archive-file-name-p dir))
+      (setq dir (file-name-directory (tramp-archive-file-name-archive dir))))
     (cl-subst nil 'none
               ;; The `is-local' and `is-connected' variables are
               ;; used to fix the behavior where Emacs hangs