helpful

commit a2fe48573173341fdeed9991b7c62702bc1fee0e
parent 0b165188463cee994c99f4f1eff7bfc7cd902fb6
Author: Wilfred Hughes <me@wilfred.me.uk>
Date:   Fri,  6 Jul 2018 14:07:08 +0100

Handle anonymous functions in keymaps

In future, we could explore showing the source code rather than just
saying it's a function. For now, just fix the crash.

Fixes #133.

Diffstat:
M
CHANGELOG.md
 | 
2
++
M
helpful.el
 | 
18
+++++++++++-------
M
test/unit-test.el
 | 
10
++++++++++

3 files changed, 23 insertions(+), 7 deletions(-)
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,6 +13,8 @@ with a link to the relevant command.
 Added a 'view callees' button which shows functions called inside the
 bodies of source code, with links to view them inside helpful.
 
+Fixed a crash on keymaps where keys are bound to anonymous functions.
+
 # v0.11
 
 Further work on syntax highlighting performance for large code
diff --git a/helpful.el b/helpful.el
@@ -752,9 +752,11 @@ vector suitable for `key-description', and COMMAND is a smbol."
      ;; Prefix keys use a keymap in the function slot of a symbol.
      (keymapp (symbol-function keymap)))
     (helpful--keymap-keys (symbol-function keymap)))
-   ;; Other symbols mean we've reached a leaf, so this is a command
-   ;; we can call.
-   ((symbolp keymap)
+   ;; Other symbols or compiled functions mean we've reached a leaf,
+   ;; so this is a command we can call.
+   ((or
+     (symbolp keymap)
+     (functionp keymap))
     `(([] ,keymap)))
    ((stringp (car keymap))
     (helpful--keymap-keys (cdr keymap)))
@@ -831,10 +833,12 @@ vector suitable for `key-description', and COMMAND is a smbol."
                          keys-and-commands))
          (formatted-commands
           (--map
-           (helpful--button
-            (symbol-name it)
-            'helpful-describe-button
-            'symbol it)
+           (if (symbolp it)
+               (helpful--button
+                (symbol-name it)
+                'helpful-describe-button
+                'symbol it)
+             "#<anonymous-function>")
            commands))
          ;; Build lines for display.
          (lines
diff --git a/test/unit-test.el b/test/unit-test.el
@@ -496,6 +496,16 @@ associated a lambda with a keybinding."
         ([3 94 61 62] smerge-diff-base-lower)
         ([3 94 61 60] smerge-diff-base-upper))))))
 
+(ert-deftest helpful--keymap-keys--anonymous-fns ()
+  (let* ((keymap (make-keymap)))
+    (define-key keymap (kbd "a")
+      (lambda () (message)))
+    (define-key keymap (kbd "a")
+      (byte-compile-sexp (lambda () (message))))
+
+    ;; Don't crash on anonymous functions in a keymap.
+    (helpful--keymap-keys keymap)))
+
 (defun helpful--dummy-command ()
   (interactive))