Don't change byte-compile-delete-errors at runtime (Bug#27340)

* lisp/emacs-lisp/eieio-core.el: Confine `cl-declaim' calls to compile
time.

1 files changed, 7 insertions, 3 deletions

diff --git a/lisp/emacs-lisp/eieio-core.el b/lisp/emacs-lisp/eieio-core.el
index dfe1c06bfaf..9d618e1dc81 100644
--- a/lisp/emacs-lisp/eieio-core.el
+++ b/lisp/emacs-lisp/eieio-core.el
@@ -84,7 +84,7 @@ Currently under control of this var:
 (progn
   ;; Arrange for field access not to bother checking if the access is indeed
   ;; made to an eieio--class object.
-  (cl-declaim (optimize (safety 0)))
+  (eval-when-compile (cl-declaim (optimize (safety 0))))
 
 (cl-defstruct (eieio--class
                (:constructor nil)
@@ -103,8 +103,12 @@ Currently under control of this var:
   options ;; storage location of tagged class option
           ; Stored outright without modifications or stripping
   )
-  ;; Set it back to the default value.
-  (cl-declaim (optimize (safety 1))))
+  ;; Set it back to the default value.  NOTE: Using the default
+  ;; `safety' value does NOT give the default
+  ;; `byte-compile-delete-errors' value.  Therefore limit this (and
+  ;; the above `cl-declaim') to compile time so that we don't affect
+  ;; code which only loads this library.
+  (eval-when-compile (cl-declaim (optimize (safety 1)))))
 
 
 (eval-and-compile