test/emacs: add workaround for Emacs 30 pp changes

This relies on the fact that setting pp-default-function has no effect
for Emacs <30.

(cherry picked from commit e3d4721b1ba4836c7646e057b50123fe994652eb)

diff --git a/test/test-lib.el b/test/test-lib.el
index 4cfb8ef163aac196558c81adae112091661036ff..bf1fab66ff549286b515ba480cb9d2fe537ff66b 100644 (file)
--- a/test/test-lib.el
+++ b/test/test-lib.el
@@ -33,6 +33,9 @@
 
 (require 'cl-lib)
 
+;; Use old pretty print algorithm, so tests don't break with Emacs 30
+(setq-default pp-default-function 'pp-28)
+
 ;; Ensure that the dynamic variables that are defined by this library
 ;; are defined by the time that we let-bind them.  This is needed
 ;; because starting with Emacs 27 undeclared variables in evaluated