Set comment-start inside helpful buffers

2 files changed, 7 insertions, 1 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 82596f7..ecacc4a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,9 @@ Fixed issues with functions that had more than one advice active.
 
 Added looking up C-style Lisp names.
 
+Set `comment-start` inside helpful buffers, to fix external packages
+relying on that variable.
+
 # v0.15
 
 Fixed a crash on formatting values.
diff --git a/helpful.el b/helpful.el
index 8619260..efbe1d3 100644
--- a/helpful.el
+++ b/helpful.el
@@ -144,7 +144,10 @@ can make Helpful very slow.")
       (setq helpful--sym symbol)
       (setq helpful--callable-p callable-p)
       (setq helpful--start-buffer current-buffer)
-      (setq helpful--associated-buffer current-buffer))
+      (setq helpful--associated-buffer current-buffer)
+      (if (helpful--primitive-p symbol callable-p)
+          (setq-local comment-start "//")
+        (setq-local comment-start ";")))
     buf))
 
 (defface helpful-heading