tdf#121168: Ensure page descriptions are correct in work document

When first node on a page is a section, then creation of a copy with
lcl_CreateWorkingDocument initially produces a document with layout
frames having wrong page descriptions applied (set to "Default Style").
The reason is that when SfxViewFrame::LoadHiddenDocument indirectly
calls SwRootFrame::Init, the sections in the document have hidden
flag set, which causes SwNodes::GoNextSection return the first node
after the first section. The returned node naturally doesn't have a
page description set, thus the initialized page frame doesn't get it.

This makes following copy to destination document use that wrong style;
if the correct page style had header/footer, then it would not be
properly copied per record in single-document output; headers/footers
would be wrong/absent.

This change forces check of page descriptions after the work document
had been created and initialized.

Change-Id: Ic196eb7fac0241f002eddd2c1d1b66dfb489bc60
Reviewed-on: https://gerrit.libreoffice.org/65383Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Tested-by: Mike Kaganski <mike.kaganski@collabora.com>
(cherry picked from commit ec928ac5)
Reviewed-on: https://gerrit.libreoffice.org/65407
Tested-by: Jenkins
Tested-by: Xisco Faulí <xiscofauli@libreoffice.org>
Reviewed-by: Michael Stahl <Michael.Stahl@cib.de>

sw/qa/extras/mailmerge/mailmerge.cxx

@@ -858,5 +858,38 @@ DECLARE_SHELL_MAILMERGE_TEST(testTdf118845, "tdf118845.fodt", "4_v01.ods", "Tabe
     CPPUNIT_ASSERT_EQUAL(OUString(""), xParagraph->getString());
 }
 
+DECLARE_SHELL_MAILMERGE_TEST(testTdf121168, "section_ps.odt", "4_v01.ods", "Tabelle1")
+{
+    // A document starting with a section on a page with non-default page style with header
+    executeMailMerge();
+    SwXTextDocument* pTextDoc = dynamic_cast<SwXTextDocument*>(mxMMComponent.get());
+    CPPUNIT_ASSERT(pTextDoc);
+    // 4 documents 1 page each, starting at odd page numbers => 7
+    CPPUNIT_ASSERT_EQUAL(sal_uInt16(7), pTextDoc->GetDocShell()->GetWrtShell()->GetPhyPageNum());
+
+    SwDoc* pDocMM = pTextDoc->GetDocShell()->GetDoc();
+    sal_uLong nSizeMM = pDocMM->GetNodes().GetEndOfContent().GetIndex()
+                        - pDocMM->GetNodes().GetEndOfExtras().GetIndex() - 2;
+    CPPUNIT_ASSERT_EQUAL(sal_uLong(16), nSizeMM);
+
+    // All even pages should be empty, all sub-documents have one page
+    const SwRootFrame* pLayout = pDocMM->getIDocumentLayoutAccess().GetCurrentLayout();
+    const SwPageFrame* pPageFrm = static_cast<const SwPageFrame*>(pLayout->Lower());
+    while (pPageFrm)
+    {
+        sal_uInt16 nPageNum = pPageFrm->GetPhyPageNum();
+        bool bOdd = (1 == (nPageNum % 2));
+        CPPUNIT_ASSERT_EQUAL(!bOdd, pPageFrm->IsEmptyPage());
+        CPPUNIT_ASSERT_EQUAL(sal_uInt16(bOdd ? 1 : 2), pPageFrm->GetVirtPageNum());
+        if (bOdd)
+        {
+            const SwPageDesc* pDesc = pPageFrm->GetPageDesc();
+            CPPUNIT_ASSERT_EQUAL(OUString("Teststyle" + OUString::number(nPageNum / 2 + 1)),
+                                 pDesc->GetName());
+        }
+        pPageFrm = static_cast<const SwPageFrame*>(pPageFrm->GetNext());
+    }
+}
+
 CPPUNIT_PLUGIN_IMPLEMENT();
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

sw/source/uibase/dbui/dbmgr.cxx

@@ -1502,6 +1502,15 @@ bool SwDBManager::MergeMailFiles(SwWrtShell* pSourceShell,
                 // ExpFields update during printing, generation of preview, etc.
                 pWorkShell->LockExpFields();
                 pWorkShell->CalcLayout();
+                // tdf#121168: Now force correct page descriptions applied to page frames. Without
+                // this, e.g., page frames starting with sections could have page descriptions set
+                // wrong. This would lead to wrong page styles applied in SwDoc::AppendDoc below.
+                pWorkShell->GetViewOptions()->SetIdle(true);
+                for (auto aLayout : pWorkShell->GetDoc()->GetAllLayouts())
+                {
+                    aLayout->FreezeLayout(false);
+                    aLayout->AllCheckPageDescs();
+                }
             }
 
             lcl_emitEvent(SfxEventHintId::SwEventFieldMerge, STR_SW_EVENT_FIELD_MERGE, xWorkDocSh);