master 1283e1d: Don't call ERT explainer on error

[Mattias Engdegård]

branch: master
commit 1283e1db9b7750a90472e7d557fdd75fcaff6446
Author: Mattias Engdegård <mattiase@acm.org>
Commit: Mattias Engdegård <mattiase@acm.org>

    Don't call ERT explainer on error
    
    * lisp/emacs-lisp/ert.el (ert--expand-should-1): If the predicate form
    signals an error, don't call an explainer because the arguments passed
    (the error and error argument, respectively) do not make any sense to
    the explainer at all.
---
 lisp/emacs-lisp/ert.el | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/lisp/emacs-lisp/ert.el b/lisp/emacs-lisp/ert.el
index 6793b37..7de07bd 100644
--- a/lisp/emacs-lisp/ert.el
+++ b/lisp/emacs-lisp/ert.el
@@ -313,12 +313,13 @@ It should only be stopped when ran from inside 
ert--run-test-internal."
                                  (list :form `(,,fn ,@,args))
                                  (unless (eql ,value ',default-value)
                                    (list :value ,value))
-                                 (let ((-explainer-
-                                        (and (symbolp ',fn-name)
-                                             (get ',fn-name 'ert-explainer))))
-                                   (when -explainer-
-                                     (list :explanation
-                                           (apply -explainer- ,args)))))
+                                 (unless (eql ,value ',default-value)
+                                   (let ((-explainer-
+                                          (and (symbolp ',fn-name)
+                                               (get ',fn-name 
'ert-explainer))))
+                                     (when -explainer-
+                                       (list :explanation
+                                             (apply -explainer- ,args))))))
                          value)
                ,value))))))))