Test include ids with unbalanced sections

Test include ids with unbalanced sections

<link linkend="include1.inc1">Include 1</link> Heading 1 Heading 1

<link linkend="include1a.inc1a">Include 1a</link> Heading 2 Heading 2 X1

X2

<link linkend="unbalanced.sect1">Section 1</link> X1

<link linkend="unbalanced.sect1.sect2">Section 2</link> X2 Heading 1

Heading 2 Heading 1

Heading 2 Heading 3