sw: layout: allow keep-with-next paragraph with fly to move back

The problem is that a paragraph that has the fo:keep-with-next="always"
and also a fly anchored at-char or at-para with style:flow-with-text="true"
will never move to the previous page, even with space available.

In SwContentFrame::MakeAll() it will first MoveBwd() and then go into
the special case "if ( bKeep && bMoveable )" which calls Calc() on the
next frame.

But this fails to move the next frame because of SwFlowFrame::IsPrevObjMove()
finding the fly with a mis-matching mpVertPosOrientFrame - that will not
be fixed until the first SwContentFrame::MakeAll() is done and
SwObjectFormatter::FormatObjsAtFrame() is called.

But SwContentFrame::MakeAll() first detects that the frame is not on
the same page as the next one despite bKeep, so it MoveFwd() again.

This happens already in OOo 3.3.

IsJoinLocked() should be a reasonably good heuristic for "is the
previous frame being formatted".

Change-Id: I86996dcb3d0c46fcb99ec9ad463569abbb8b99f0
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/130033
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>

3 files changed, 210 insertions, 0 deletions

diff --git a/sw/qa/extras/layout/data/keep-with-next-fly.fodt b/sw/qa/extras/layout/data/keep-with-next-fly.fodt
new file mode 100644
index 000000000000..13d6785f4e1f
--- /dev/null
+++ b/sw/qa/extras/layout/data/keep-with-next-fly.fodt
@@ -0,0 +1,146 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<office:document xmlns:officeooo="http://openoffice.org/2009/office" xmlns:css3t="http://www.w3.org/TR/css3-text/" xmlns:grddl="http://www.w3.org/2003/g/data-view#" xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:formx="urn:openoffice:names:experimental:ooxml-odf-interop:xmlns:form:1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:chart="urn:oasis:names:tc:opendocument:xmlns:chart:1.0" xmlns:svg="urn:oasis:names:tc:opendocument:xmlns:svg-compatible:1.0" xmlns:text="urn:oasis:names:tc:opendocument:xmlns:text:1.0" xmlns:oooc="http://openoffice.org/2004/calc" xmlns:style="urn:oasis:names:tc:opendocument:xmlns:style:1.0" xmlns:ooow="http://openoffice.org/2004/writer" xmlns:meta="urn:oasis:names:tc:opendocument:xmlns:meta:1.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:rpt="http://openoffice.org/2005/report" xmlns:draw="urn:oasis:names:tc:opendocument:xmlns:drawing:1.0" xmlns:config="urn:oasis:names:tc:opendocument:xmlns:config:1.0" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:fo="urn:oasis:names:tc:opendocument:xmlns:xsl-fo-compatible:1.0" xmlns:ooo="http://openoffice.org/2004/office" xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0" xmlns:dr3d="urn:oasis:names:tc:opendocument:xmlns:dr3d:1.0" xmlns:table="urn:oasis:names:tc:opendocument:xmlns:table:1.0" xmlns:number="urn:oasis:names:tc:opendocument:xmlns:datastyle:1.0" xmlns:of="urn:oasis:names:tc:opendocument:xmlns:of:1.2" xmlns:calcext="urn:org:documentfoundation:names:experimental:calc:xmlns:calcext:1.0" xmlns:tableooo="http://openoffice.org/2009/table" xmlns:drawooo="http://openoffice.org/2010/draw" xmlns:loext="urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.0" xmlns:dom="http://www.w3.org/2001/xml-events" xmlns:field="urn:openoffice:names:experimental:ooo-ms-interop:xmlns:field:1.0" xmlns:math="http://www.w3.org/1998/Math/MathML" xmlns:form="urn:oasis:names:tc:opendocument:xmlns:form:1.0" xmlns:script="urn:oasis:names:tc:opendocument:xmlns:script:1.0" xmlns:xforms="http://www.w3.org/2002/xforms" office:version="1.3" office:mimetype="application/vnd.oasis.opendocument.text">
+ <office:meta><meta:creation-date>2022-02-16T15:01:24.088191425</meta:creation-date><dc:date>2022-02-16T15:16:50.103419678</dc:date><meta:editing-duration>PT15M29S</meta:editing-duration><meta:editing-cycles>1</meta:editing-cycles><meta:document-statistic meta:table-count="0" meta:image-count="1" meta:object-count="0" meta:page-count="2" meta:paragraph-count="1" meta:word-count="5" meta:character-count="26" meta:non-whitespace-character-count="22"/><meta:generator>LibreOfficeDev/7.4.0.0.alpha0$Linux_X86_64 LibreOffice_project/16748887dd277bd63034e07b5e2a86740235b315</meta:generator></office:meta>
+ <office:font-face-decls>
+  <style:font-face style:name="Liberation Serif" svg:font-family="'Liberation Serif'" style:font-family-generic="roman" style:font-pitch="variable"/>
+  <style:font-face style:name="Lohit Devanagari1" svg:font-family="'Lohit Devanagari'" style:font-family-generic="system" style:font-pitch="variable"/>
+  <style:font-face style:name="Source Han Serif CN" svg:font-family="'Source Han Serif CN'" style:font-family-generic="system" style:font-pitch="variable"/>
+ </office:font-face-decls>
+ <office:styles>
+  <draw:gradient draw:name="gradient" draw:style="linear" draw:start-color="#000000" draw:end-color="#ffffff" draw:start-intensity="100%" draw:end-intensity="100%" draw:angle="0deg" draw:border="0%"/>
+  <draw:hatch draw:name="hatch" draw:style="single" draw:color="#3465a4" draw:distance="0.02cm" draw:rotation="0"/>
+  <style:default-style style:family="graphic">
+   <style:graphic-properties svg:stroke-color="#3465a4" draw:fill-color="#729fcf" fo:wrap-option="no-wrap" draw:shadow-offset-x="0.3cm" draw:shadow-offset-y="0.3cm" draw:start-line-spacing-horizontal="0.283cm" draw:start-line-spacing-vertical="0.283cm" draw:end-line-spacing-horizontal="0.283cm" draw:end-line-spacing-vertical="0.283cm" style:flow-with-text="false"/>
+   <style:paragraph-properties style:text-autospace="ideograph-alpha" style:line-break="strict" style:writing-mode="lr-tb" style:font-independent-line-spacing="false">
+    <style:tab-stops/>
+   </style:paragraph-properties>
+   <style:text-properties style:use-window-font-color="true" loext:opacity="0%" loext:color-lum-mod="100%" loext:color-lum-off="0%" style:font-name="Liberation Serif" fo:font-size="12pt" fo:language="de" fo:country="DE" style:letter-kerning="true" style:font-name-asian="Source Han Serif CN" style:font-size-asian="10.5pt" style:language-asian="zh" style:country-asian="CN" style:font-name-complex="Lohit Devanagari1" style:font-size-complex="12pt" style:language-complex="hi" style:country-complex="IN"/>
+  </style:default-style>
+  <style:default-style style:family="paragraph">
+   <style:paragraph-properties fo:orphans="2" fo:widows="2" fo:hyphenation-ladder-count="no-limit" style:text-autospace="ideograph-alpha" style:punctuation-wrap="hanging" style:line-break="strict" style:tab-stop-distance="1.251cm" style:writing-mode="page"/>
+   <style:text-properties style:use-window-font-color="true" loext:opacity="0%" style:font-name="Liberation Serif" fo:font-size="12pt" fo:language="de" fo:country="DE" style:letter-kerning="true" style:font-name-asian="Source Han Serif CN" style:font-size-asian="10.5pt" style:language-asian="zh" style:country-asian="CN" style:font-name-complex="Lohit Devanagari1" style:font-size-complex="12pt" style:language-complex="hi" style:country-complex="IN" fo:hyphenate="false" fo:hyphenation-remain-char-count="2" fo:hyphenation-push-char-count="2" loext:hyphenation-no-caps="false"/>
+  </style:default-style>
+  <style:default-style style:family="table">
+   <style:table-properties table:border-model="collapsing"/>
+  </style:default-style>
+  <style:default-style style:family="table-row">
+   <style:table-row-properties fo:keep-together="auto"/>
+  </style:default-style>
+  <style:style style:name="Standard" style:family="paragraph" style:class="text"/>
+  <style:style style:name="Graphics" style:family="graphic">
+   <style:graphic-properties text:anchor-type="paragraph" svg:x="0cm" svg:y="0cm" style:wrap="dynamic" style:number-wrapped-paragraphs="no-limit" style:wrap-contour="false" style:vertical-pos="top" style:vertical-rel="paragraph" style:horizontal-pos="center" style:horizontal-rel="paragraph"/>
+  </style:style>
+  <text:outline-style style:name="Outline">
+   <text:outline-level-style text:level="1" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+   <text:outline-level-style text:level="2" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+   <text:outline-level-style text:level="3" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+   <text:outline-level-style text:level="4" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+   <text:outline-level-style text:level="5" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+   <text:outline-level-style text:level="6" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+   <text:outline-level-style text:level="7" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+   <text:outline-level-style text:level="8" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+   <text:outline-level-style text:level="9" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+   <text:outline-level-style text:level="10" style:num-format="">
+    <style:list-level-properties text:list-level-position-and-space-mode="label-alignment">
+     <style:list-level-label-alignment text:label-followed-by="listtab"/>
+    </style:list-level-properties>
+   </text:outline-level-style>
+  </text:outline-style>
+  <text:notes-configuration text:note-class="footnote" style:num-format="1" text:start-value="0" text:footnotes-position="page" text:start-numbering-at="document"/>
+  <text:notes-configuration text:note-class="endnote" style:num-format="i" text:start-value="0"/>
+  <text:linenumbering-configuration text:number-lines="false" text:offset="0.499cm" style:num-format="1" text:number-position="left" text:increment="5"/>
+ </office:styles>
+ <office:automatic-styles>
+  <style:style style:name="P1" style:family="paragraph" style:parent-style-name="Standard" style:master-page-name="">
+   <loext:graphic-properties draw:fill-gradient-name="gradient" draw:fill-hatch-name="hatch"/>
+   <style:paragraph-properties style:page-number="auto" fo:break-before="auto" fo:break-after="auto"/>
+   <style:text-properties/>
+  </style:style>
+  <style:style style:name="P2" style:family="paragraph" style:parent-style-name="Standard" style:master-page-name="">
+   <loext:graphic-properties draw:fill-gradient-name="gradient" draw:fill-hatch-name="hatch"/>
+   <style:paragraph-properties style:page-number="auto" fo:break-before="auto" fo:break-after="auto" fo:keep-with-next="always"/>
+   <style:text-properties/>
+  </style:style>
+  <style:style style:name="fr1" style:family="graphic" style:parent-style-name="Graphics">
+   <style:graphic-properties style:horizontal-pos="center" style:horizontal-rel="paragraph" style:mirror="none" fo:clip="rect(0cm, 0cm, 0cm, 0cm)" draw:luminance="0%" draw:contrast="0%" draw:red="0%" draw:green="0%" draw:blue="0%" draw:gamma="100%" draw:color-inversion="false" draw:image-opacity="100%" draw:color-mode="standard" style:flow-with-text="true"/>
+  </style:style>
+  <style:page-layout style:name="pm1">
+   <style:page-layout-properties fo:page-width="10.5cm" fo:page-height="14.801cm" style:num-format="1" style:print-orientation="portrait" fo:margin-top="2cm" fo:margin-bottom="2cm" fo:margin-left="2cm" fo:margin-right="2cm" style:writing-mode="lr-tb" style:footnote-max-height="0cm" loext:margin-gutter="0cm">
+    <style:footnote-sep style:width="0.018cm" style:distance-before-sep="0.101cm" style:distance-after-sep="0.101cm" style:line-style="solid" style:adjustment="left" style:rel-width="25%" style:color="#000000"/>
+   </style:page-layout-properties>
+   <style:header-style/>
+   <style:footer-style/>
+  </style:page-layout>
+  <number:number-style style:name="N0">
+   <number:number number:min-integer-digits="1"/>
+  </number:number-style>
+ </office:automatic-styles>
+ <office:master-styles>
+  <style:master-page style:name="Standard" style:page-layout-name="pm1"/>
+ </office:master-styles>
+ <office:body>
+  <office:text text:use-soft-page-breaks="true">
+   <text:variable-decls>
+    <text:variable-decl office:value-type="float" text:name="abc"/>
+   </text:variable-decls>
+   <text:sequence-decls>
+    <text:sequence-decl text:display-outline-level="0" text:name="Illustration"/>
+    <text:sequence-decl text:display-outline-level="0" text:name="Table"/>
+    <text:sequence-decl text:display-outline-level="0" text:name="Text"/>
+    <text:sequence-decl text:display-outline-level="0" text:name="Drawing"/>
+    <text:sequence-decl text:display-outline-level="0" text:name="Figure"/>
+   </text:sequence-decls>
+   <text:p text:style-name="P1"><text:variable-set text:name="abc" text:formula="ooow:1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890" office:value-type="float" office:value="INF" style:data-style-name="N0">** Expression is faulty **</text:variable-set></text:p>
+   <text:p text:style-name="P2"><draw:frame draw:style-name="fr1" draw:name="Image1" text:anchor-type="char" svg:width="0.503cm" svg:height="0.503cm" draw:z-index="0"><draw:image draw:mime-type="image/png">
+      <office:binary-data>iVBORw0KGgoAAAANSUhEUgAAABMAAAATCAYAAAByUDbMAAAABGdBTUEAANbY1E9YMgAAABl0
+       RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAAFpSURBVHjaYvz//z8DtQBAADER
+       o+jjZGuibAQIICZiDOK/cgzFwEnrV/4HYXS1AAHERIxBR58yMiAb2DtzM1b1AAHERIxBIIBu
+       IDYAEEBMxBjE0bgdxcBL3vcZLl16jaEPIICYiDFIU9MSw8BeoeUYhgEEEBMxBnFx8WE1EN3L
+       AAHERIxBIECMgQABxAhKtPgM+vbtE9xmGP/69eMMP+o9wWLW0kD9OlYM/LlHGQECiAndoKg/
+       USgGgTTmdS8C0yA+zIUgdeguBAggljtWdQwMVkDXACWMjd0ZXRun/Id5DWTA9C23GSaVxoEN
+       zISoARvoamnBYF2/hPHs2Z3/z0JdDhBADCBvIuPkhsn/QeDr14//QWwQjY0PVYeiFyCA8OaA
+       3cdPoEQAiI8PAAQQEwMVAUAAsWATBAX0jx9fsWrAJQ4CAAGE1TBQwOMC9+9fwikHEEBYDQPF
+       IAzIe8TglEMHAAHESM2SFiDAADEwCe4BJwcYAAAAAElFTkSuQmCC
+      </office:binary-data>
+     </draw:image>
+    </draw:frame><text:soft-page-break/></text:p>
+   <text:p text:style-name="Standard"/>
+  </office:text>
+ </office:body>
+</office:document>
\ No newline at end of file
diff --git a/sw/qa/extras/layout/layout.cxx b/sw/qa/extras/layout/layout.cxx
index 1618b86a1363..cf78f167dc7e 100644
--- a/sw/qa/extras/layout/layout.cxx
+++ b/sw/qa/extras/layout/layout.cxx
@@ -2608,6 +2608,58 @@ CPPUNIT_TEST_FIXTURE(SwLayoutWriter, testTdf112290)
     assertXPath(pXml, "/root/page/body/txt/LineBreak[2]", "Line", "Xxxx Xxxx");
 }
 
+CPPUNIT_TEST_FIXTURE(SwLayoutWriter, testKeepWithNextPlusFlyFollowTextFlow)
+{
+    createSwDoc(DATA_DIRECTORY, "keep-with-next-fly.fodt");
+
+    {
+        xmlDocUniquePtr pXmlDoc = parseLayoutDump();
+        // 3 text frames on page 1
+        assertXPath(pXmlDoc, "/root/page[1]/body/infos/bounds", "bottom", "7540");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[1]/infos/bounds", "height", "276");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[2]/infos/bounds", "height", "276");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[2]/anchored/fly", 1);
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[2]/anchored/fly/infos/bounds", "top", "1694");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[3]/infos/bounds", "height", "276");
+        assertXPath(pXmlDoc, "/root/page", 1);
+        discardDumpedLayout();
+    }
+
+    dispatchCommand(mxComponent, ".uno:Fieldnames", {});
+    Scheduler::ProcessEventsToIdle();
+
+    {
+        xmlDocUniquePtr pXmlDoc = parseLayoutDump();
+        // 1 text frame on page 1, and some empty space
+        assertXPath(pXmlDoc, "/root/page[1]/body/infos/bounds", "bottom", "7540");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[1]/infos/bounds", "height", "5796");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[1]/infos/bounds", "bottom", "7213");
+        // 2 text frames on page 2
+        assertXPath(pXmlDoc, "/root/page[2]/body/txt[1]/infos/bounds", "height", "276");
+        assertXPath(pXmlDoc, "/root/page[2]/body/txt[1]/anchored/fly", 1);
+        assertXPath(pXmlDoc, "/root/page[2]/body/txt[1]/anchored/fly/infos/bounds", "top", "10093");
+        assertXPath(pXmlDoc, "/root/page[2]/body/txt[2]/infos/bounds", "height", "276");
+        assertXPath(pXmlDoc, "/root/page", 2);
+        discardDumpedLayout();
+    }
+
+    dispatchCommand(mxComponent, ".uno:Fieldnames", {});
+    Scheduler::ProcessEventsToIdle();
+
+    {
+        xmlDocUniquePtr pXmlDoc = parseLayoutDump();
+        // 3 text frames on page 1
+        assertXPath(pXmlDoc, "/root/page[1]/body/infos/bounds", "bottom", "7540");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[1]/infos/bounds", "height", "276");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[2]/infos/bounds", "height", "276");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[2]/anchored/fly", 1);
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[2]/anchored/fly/infos/bounds", "top", "1694");
+        assertXPath(pXmlDoc, "/root/page[1]/body/txt[3]/infos/bounds", "height", "276");
+        assertXPath(pXmlDoc, "/root/page", 1);
+        discardDumpedLayout();
+    }
+}
+
 CPPUNIT_TEST_FIXTURE(SwLayoutWriter, testTdf122607)
 {
     createSwDoc(DATA_DIRECTORY, "tdf122607.odt");
diff --git a/sw/source/core/layout/flowfrm.cxx b/sw/source/core/layout/flowfrm.cxx
index 53f3881f1d56..c53512b2763a 100644
--- a/sw/source/core/layout/flowfrm.cxx
+++ b/sw/source/core/layout/flowfrm.cxx
@@ -1139,6 +1139,18 @@ bool SwFlowFrame::IsPrevObjMove() const
         OSL_ENSURE( SwFlowFrame::CastFlowFrame( pPre ), "new flowfrm?" );
         if( SwFlowFrame::CastFlowFrame( pPre )->IsAnFollow( this ) )
             return false;
+        if (SwFlowFrame::CastFlowFrame(pPre)->IsJoinLocked())
+        {
+            SwBorderAttrAccess baa(SwFrame::GetCache(), pPre);
+            SwBorderAttrs const& rAttrs(*baa.Get());
+            if (SwFlowFrame::CastFlowFrame(pPre)->IsKeep(rAttrs.GetAttrSet().GetKeep(), pPre->GetBreakItem()))
+            {   // pPre is currently being formatted - maybe it moved back but
+                // its objects still have the old page's body as
+                // mpVertPosOrientFrame and SwContentFrame::MakeAll() is calling
+                // pNxt->Calc() in this case so allow this frame to move back
+                return false; // too, else pPre is forced to move forward again.
+            }
+        }
         SwLayoutFrame* pPreUp = pPre->GetUpper();
         // If the upper is a SectionFrame, or a column of a SectionFrame, we're
         // allowed to protrude out of it.  However, we need to respect the