This code used to work but that's no longer the case and I'll explain why.

<b:if cond='data:blog.searchQuery'>
 <b:if cond='data:olderPageUrl == data:newerPageUrl'>
  *SEARCH ERROR MSG*
 </b:if >
</b:if>

It's no secret that page navigation is a mess. It seems like you guys are
playing whack-a-mole with these bugs. Perhaps an overhaul to the page
navigation code is needed? You guys do seem to fix problems but it's as-if
fixing one problem causes another. I don't think it's on purpose it just
gives me the impression that the pagenav codebase is very complicated. I've
been trying my best to code workarounds to the bugs. This USED to work
because on 0 result pages older/newerPageUrl would be identical. This is no
longer the case. Unfortunately it's still possible for visitors to be taken
to a 0 result page. This has been a problem forever. I have no idea how to
resolve it from my end.

The only other solution I see to this is matching the navMessage data tag
but that's rather difficult. Feel free to give it a shot.

*Search example raw HTML*

No posts matching the query: <b>QUERY</b>. <a
href="http://blogger2ools.mystady.com/">Show all posts</a>

*Label Pages*

This code *does* work for label pages though. Ideally I wouldn't even need
this code but I digress.

<b:if cond='data:blog.searchLabel'>
 <b:if cond='data:olderPageUrl == data:newerPageUrl'>
  *LABEL ERROR MSG*
 </b:if >
</b:if>

Anyone have any clever solutions?