Ensure that we don't call find-file with propertized strings0.4

This breaks recentf, as it serialises the propertized string to a file
~/.recentf and then Emacs can't read the file on startup.

Fixes #68.

2 files changed, 10 insertions, 1 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 721948c..bf0033b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,9 @@ interactively defined functions being edebugged.
 
 Added a cleanup command `helpful-kill-buffers`.
 
+Fixed an issue with helpful making recentf write broken paths to
+~/.recentf, breaking Emacs startup.
+
 # v0.3
 
 Fixed a crash on autoloaded functions that aren't loaded yet.
diff --git a/helpful.el b/helpful.el
index 7b536c8..03740cb 100644
--- a/helpful.el
+++ b/helpful.el
@@ -225,9 +225,15 @@ or disable if already enabled."
   'follow-link t
   'help-echo "Navigate to definition")
 
+(defun helpful--no-properties (s)
+  "Return a copy of S without any properties."
+  (with-temp-buffer
+    (insert s)
+    (buffer-substring-no-properties (point-min) (point-max))))
+
 (defun helpful--navigate (button)
   "Navigate to the path this BUTTON represents."
-  (find-file (button-get button 'path))
+  (find-file (helpful--no-properties (button-get button 'path)))
   ;; We use `get-text-property' to work around an Emacs 25 bug:
   ;; http://git.savannah.gnu.org/cgit/emacs.git/commit/?id=f7c4bad17d83297ee9a1b57552b1944020f23aea
   (-when-let (pos (get-text-property button 'position