The following FO code is created by an XSL transformation. The result shall be a long PDF containing multiple pages. The content of page 1 might spill over to the next page. There might be the need for deliberately adding another page (Page 2 of 2 in this example). When I run the sample through a FO interpreter (I tried Apache's FOP as well as Compart's DocBridgeMill), I get this PDF:
I want to get rid of the empty page.
<?xml version="1.0" encoding="UTF-8"?>
<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
<fo:layout-master-set>
<fo:simple-page-master
margin-top="5mm" margin-left="10mm"
page-width="210mm" page-height="50mm" master-name="FirstPage">
<fo:region-body />
</fo:simple-page-master>
<fo:simple-page-master
margin-top="10mm" margin-left="10mm"
page-width="210mm" page-height="50mm" master-name="OtherPage">
<fo:region-body />
</fo:simple-page-master>
<fo:page-sequence-master
master-name="PageSequence">
<fo:single-page-master-reference
master-reference="FirstPage" />
<fo:repeatable-page-master-reference
master-reference="OtherPage" />
</fo:page-sequence-master>
<fo:page-sequence-master
master-name="FollowingPages">
<fo:repeatable-page-master-reference
master-reference="OtherPage" />
</fo:page-sequence-master>
</fo:layout-master-set>
<fo:page-sequence initial-page-number="1"
master-reference="PageSequence">
<fo:flow flow-name="xsl-region-body">
<fo:block>
Page
<fo:page-number />
of
<fo:page-number-citation
ref-id="5DAF3593E443DF58C1258934005BD76B" />
</fo:block>
<fo:block id="5DAF3593E443DF58C1258934005BD76B" />
</fo:flow>
</fo:page-sequence>
<fo:page-sequence initial-page-number="1"
master-reference="PageSequence">
<fo:flow flow-name="xsl-region-body">
<fo:block>
Page
<fo:page-number />
of
<fo:page-number-citation
ref-id="0C36B169CFBCD3DFC12589360067818E" />
</fo:block>
</fo:flow>
</fo:page-sequence>
<fo:page-sequence master-reference="FollowingPages">
<fo:flow flow-name="xsl-region-body">
<fo:block>
Page
<fo:page-number />
of
<fo:page-number-citation
ref-id="0C36B169CFBCD3DFC12589360067818E" />
</fo:block>
<fo:block id="0C36B169CFBCD3DFC12589360067818E" />
</fo:flow>
</fo:page-sequence>
</fo:root>
XSL-FO is written with the assumption that odd-numbered pages are on the recto (left, for us) side of a two-page spread and that even-numbered pages are on the verso (back, or right) side.
The initial-page-number="1" on the second fo:page-sequence causes the formatter to emit the blank page after the first page sequence so that the second page sequence starts on a recto page as requested (however inadvertently). See https://www.w3.org/TR/xsl11/#initial-page-number
If you were using Antenna House Formatter (and added xmlns:axf="http://www.antennahouse.com/names/XSL/Extensions" to the XSL-FO), you could use the axf:origin-id extension to get the effect that you want. See https://www.antenna.co.jp/AHF/help/en/ahf-ext.html#axf.origin-id
<fo:page-sequence initial-page-number="1" id="seq1"
master-reference="PageSequence">
<fo:flow flow-name="xsl-region-body">
<fo:block>
Page
<fo:page-number />
of
<fo:page-number-citation-last
ref-id="seq1" />
</fo:block>
</fo:flow>
</fo:page-sequence>
<fo:page-sequence id="seq2"
master-reference="PageSequence">
<fo:flow flow-name="xsl-region-body">
<fo:block>
Page
<fo:page-number axf:origin-id="seq2" />
of
<fo:page-number-citation axf:origin-id="seq2"
ref-id="seq-last" />
</fo:block>
</fo:flow>
</fo:page-sequence>
<fo:page-sequence master-reference="FollowingPages"
id="seq-last">
<fo:flow flow-name="xsl-region-body">
<fo:block>
Page
<fo:page-number axf:origin-id="seq2" />
of
<fo:page-number-citation-last axf:origin-id="seq2"
ref-id="seq-last" />
</fo:block>
</fo:flow>
</fo:page-sequence>