[nongnu] elpa/nix-mode d2f4a629a8 258/500: Only show derivations in nix store

[ELPA Syncer]

branch: elpa/nix-mode
commit d2f4a629a846e1f0d2fd4dbe67e127719ff3c238
Author: Matthew Bauer <mjbauer95@gmail.com>
Commit: Matthew Bauer <mjbauer95@gmail.com>

    Only show derivations in nix store
---
 nix-drv-mode.el | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/nix-drv-mode.el b/nix-drv-mode.el
index fdbc4f82f9..b9e184270f 100644
--- a/nix-drv-mode.el
+++ b/nix-drv-mode.el
@@ -25,22 +25,24 @@
 (defun nix-drv-mode ()
   "Pretty print Nix’s .drv files."
   (interactive)
-  (let ((inhibit-read-only t))
+  (when (string-match (format "^%s/" nix-store-dir) (buffer-file-name))
     (if nix-drv-mode
         (progn
           (erase-buffer)
           (insert-file-contents (buffer-file-name))
-          (setq nix-drv-mode nil))
-      (setq nix-drv-mode t)
-      (erase-buffer)
-      (insert (shell-command-to-string
-               (format "%s show-derivation \"%s\""
-                      nix-executable
-                      (buffer-file-name))))
-      (json-mode)
-      (set-buffer-modified-p nil))
-    (set-buffer-modified-p nil)
-    (read-only-mode 1)))
+          (setq nix-drv-mode nil)
+          (set-buffer-modified-p nil)
+          (read-only-mode nil))
+      (let ((inhibit-read-only t))
+        (setq nix-drv-mode t)
+        (erase-buffer)
+        (insert (shell-command-to-string
+                 (format "%s show-derivation \"%s\""
+                        nix-executable
+                        (buffer-file-name))))
+        (json-mode)
+        (set-buffer-modified-p nil)
+        (read-only-mode 1)))))
 
 (provide 'nix-drv-mode)
 ;;; nix-drv-mode.el ends here