stablerangecache: sanity check subranges
Try to detect invalid conditions on insert as would result in deep
recursions and final aborts much later. This has been observed on two
different machines and the check makes it hopefully possible to find the
origin of the problem.
<!DOCTYPE html>
<html $if(lang)$ lang="$lang$" $endif$ dir="ltr">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>$if(title)$$title$$endif$</title>
$if(template_css)$
<link rel="stylesheet" href="$template_css$">
$else$
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/uikit/2.26.4/css/uikit.gradient.css">
$endif$
<link rel="stylesheet" href="style.css">
<script src="https://code.jquery.com/jquery-2.2.1.min.js"></script>
<script src="uikit.js"></script>
<script src="scripts.js"></script>
<script src="jquery.sticky-kit.js "></script>
<meta name="generator" content="pandoc-uikit" />
$for(author-meta)$
<meta name="author" content="$author-meta$" />
$endfor$
$if(date-meta)$
<meta name="date" content="$date-meta$" />
$endif$
<title>$if(title-prefix)$$title-prefix$ - $endif$$pagetitle$</title>
<style type="text/css">code{white-space: pre;}</style>
$if(quotes)$
<style type="text/css">q { quotes: "“" "”" "‘" "’"; }</style>
$endif$
$if(highlighting-css)$
<style type="text/css">
$highlighting-css$
</style>
$endif$
$for(css)$
<link rel="stylesheet" href="$css$" $if(html5)$$else$type="text/css" $endif$/>
$endfor$
$if(math)$
$math$
$endif$
$for(header-includes)$
$header-includes$
$endfor$
</head>
<body>
<div class="uk-container uk-container-center uk-margin-top uk-margin-large-bottom">
$if(title)$
<div class="uk-grid" data-uk-grid-margin>
<div class="uk-width-1-1">
<h1 class="uk-heading-large">$title$</h1>
$if(date)$
<h3 class="uk-heading-large">$date$</p></h3>
$endif$
$for(author)$
<p class="uk-text-large">$author$</p>
$endfor$
</div>
</div>
$endif$
<div class="uk-grid" data-uk-grid-margin >
<div class="uk-width-medium-1-4">
<div class="uk-overflow-container" data-uk-sticky="{top:25,media: 768}">
<div class="uk-panel uk-panel-box menu-begin" >
$if(toc)$
$toc$
$endif$
</div>
</div>
</div>
<div class="uk-width-medium-3-4">
$body$
</div>
</div>
$if(analytics)$
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
ga('create', '$analytics$', 'auto');
ga('send', 'pageview');
$endif$
</div>
</body>
</html>