When not customized, it becomes buffer-local when it can be inferred
from the file name or buffer contents.
+** New user option `isearch-resume-enabled'.
+This option can be disabled, to avoid the normal behaviour of isearch
+which puts calls to `isearch-resume' in the command history.
+
** When the *scratch* buffer is recreated, its mode is set from
initial-major-mode, which normally is lisp-interaction-mode,
instead of using default-major-mode.