tdf#118719 sw Hide Whitespace: fix height of last-but-one page

Regression from commit 49b67cdc
(tdf#96961 sw Hide Whitespace: still show whitespace on the last page,
2016-01-08), the problem was that in case a page used to be the last one
but no longer is, then its height was kept unchanged.

Fix this by invalidating the size of the old last page after the
insertion of the new last page, this way SwPageFrame::MakeAll() will be
called later to resize the page.

Change-Id: I672a70a77af5d306b1f8bd0b5ad6c2e375497124
Reviewed-on: https://gerrit.libreoffice.org/72256
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

sw/qa/extras/layout/layout.cxx

@@ -40,7 +40,10 @@ protected:
 
 SwDoc* SwLayoutWriter::createDoc(const char* pName)
 {
-    load(DATA_DIRECTORY, pName);
+    if (!pName)
+        loadURL("private:factory/swriter", nullptr);
+    else
+        load(DATA_DIRECTORY, pName);
 
     SwXTextDocument* pTextDoc = dynamic_cast<SwXTextDocument*>(mxComponent.get());
     CPPUNIT_ASSERT(pTextDoc);
@@ -2973,6 +2976,28 @@ CPPUNIT_TEST_FIXTURE(SwLayoutWriter, testTdf116501)
     createDoc("tdf116501.odt");
 }
 
+CPPUNIT_TEST_FIXTURE(SwLayoutWriter, testTdf118719)
+{
+    // Insert a page break.
+    SwDoc* pDoc = createDoc();
+    SwWrtShell* pWrtShell = pDoc->GetDocShell()->GetWrtShell();
+
+    // Enable hide whitespace mode.
+    SwViewOption aViewOptions(*pWrtShell->GetViewOptions());
+    aViewOptions.SetHideWhitespaceMode(true);
+    pWrtShell->ApplyViewOptions(aViewOptions);
+
+    pWrtShell->Insert("first");
+    pWrtShell->InsertPageBreak();
+    pWrtShell->Insert("second");
+
+    // Without the accompanying fix in place, this test would have failed, as the height of the
+    // first page was 15840 twips, instead of the much smaller 276.
+    sal_Int32 nOther = parseDump("/root/page[1]/infos/bounds", "height").toInt32();
+    sal_Int32 nLast = parseDump("/root/page[2]/infos/bounds", "height").toInt32();
+    CPPUNIT_ASSERT_GREATER(nOther, nLast);
+}
+
 CPPUNIT_PLUGIN_IMPLEMENT();
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

sw/source/core/layout/pagechg.cxx

@@ -1261,6 +1261,18 @@ namespace
             SAL_INFO( "sw.pageframe", "doInsertPage - insert empty p: "
                                       << pPage << " d: " << pDesc );
         pPage->Paste( pRoot, pSibling );
+
+        SwViewShell* pViewShell = pRoot->GetCurrShell();
+        if (pViewShell && pViewShell->GetViewOptions()->IsHideWhitespaceMode())
+        {
+            // Hide-whitespace mode does not shrink the last page, so resize the page that used to
+            // be the last one.
+            if (SwFrame* pPrevPage = pPage->GetPrev())
+            {
+                pPrevPage->InvalidateSize();
+            }
+        }
+
         pPage->PreparePage( bFootnote );
         // If the sibling has no body text, destroy it as long as it is no footnote page.
         if ( pSibling && !pSibling->IsFootnotePage() &&