Info-isearch-search is a variable defined in `info.el'.
Its value is

If non-nil, isearch in Info searches through multiple nodes.
Before leaving the initial Info node, where isearch was started,
it fails once with the error message [end of node], and with
subsequent C-s/C-r continues through other nodes without failing
with this error message in other nodes. When isearch fails for
the rest of the manual, it displays the error message [end of manual],
wraps around the whole manual and restarts the search from the top/final
node depending on search direction.

Setting this option to nil restores the default isearch behavior
with wrapping around the current Info node.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 22.1 of Emacs.