DOCX import: fix assertion failure when redline ends right before a ToC

This was always a problem, but now more visible since commit
8b3c861c46ae12d21b7b3a550e2daa21d2006b77 (tdf#89991 DOCX: import Show
changes from older formats, 2019-06-13), as it now affects more
documents: tracked changes can be hidden by the time the initial layout
is created.

With that aside, the immediate problem is an assertion failure in
InsertCnt_(), because it assumes that an end node for a section has to
have a matching pActualSection, created by start node of the same
section. This will fail in case the start node is hidden, but not the
end node.

The deeper problem is that redlines are not supposed to cross section
boundaries: if e.g. multiple cells are selected in a table and the user
deletes while tracking changes, then the UI creates multiple redlines
instead.  The problem here is similar: a delete redline ends right
before the section start, so when SwNodes::InsertTextSection() inserts a
section node, the end of that redline is automatically moved to the
start of the section content (its index increases, the actual SwNode
doesn't change).

Fix the problem by explicitly checking for a redline end at ToX start and
moving it back to the end of last content node. This matches the doc
model produced by the WW8 import.

(cherry picked from commit 69edfcf789db1920273191d93fae0bc03f385b81)

Conflicts:
	sw/source/core/docnode/ndsect.cxx

Change-Id: Ic7b279185a20d2a32abd054d3fc6be530ddde12a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/105473
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

5 files changed, 147 insertions, 0 deletions

diff --git a/sw/CppunitTest_sw_core_docnode.mk b/sw/CppunitTest_sw_core_docnode.mk
new file mode 100644
index 000000000000..daa9666a99d4
--- /dev/null
+++ b/sw/CppunitTest_sw_core_docnode.mk
@@ -0,0 +1,73 @@
+# -*- Mode: makefile-gmake; tab-width: 4; indent-tabs-mode: t -*-
+#*************************************************************************
+#
+# This file is part of the LibreOffice project.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+#*************************************************************************
+
+$(eval $(call gb_CppunitTest_CppunitTest,sw_core_docnode))
+
+$(eval $(call gb_CppunitTest_use_common_precompiled_header,sw_core_docnode))
+
+$(eval $(call gb_CppunitTest_add_exception_objects,sw_core_docnode, \
+    sw/qa/core/docnode/docnode \
+))
+
+$(eval $(call gb_CppunitTest_use_libraries,sw_core_docnode, \
+    comphelper \
+    cppu \
+    cppuhelper \
+    editeng \
+    sal \
+    sfx \
+    sw \
+    test \
+    unotest \
+    utl \
+    vcl \
+    svt \
+    tl \
+    svl \
+))
+
+$(eval $(call gb_CppunitTest_use_externals,sw_core_docnode,\
+    boost_headers \
+    libxml2 \
+))
+
+$(eval $(call gb_CppunitTest_set_include,sw_core_docnode,\
+    -I$(SRCDIR)/sw/inc \
+    -I$(SRCDIR)/sw/source/core/inc \
+    -I$(SRCDIR)/sw/source/uibase/inc \
+    -I$(SRCDIR)/sw/qa/inc \
+    $$(INCLUDE) \
+))
+
+$(eval $(call gb_CppunitTest_use_api,sw_core_docnode,\
+    udkapi \
+    offapi \
+    oovbaapi \
+))
+
+$(eval $(call gb_CppunitTest_use_ure,sw_core_docnode))
+$(eval $(call gb_CppunitTest_use_vcl,sw_core_docnode))
+
+$(eval $(call gb_CppunitTest_use_rdb,sw_core_docnode,services))
+
+$(eval $(call gb_CppunitTest_use_custom_headers,sw_core_docnode,\
+    officecfg/registry \
+))
+
+$(eval $(call gb_CppunitTest_use_configuration,sw_core_docnode))
+
+$(eval $(call gb_CppunitTest_use_uiconfigs,sw_core_docnode, \
+    modules/swriter \
+))
+
+$(eval $(call gb_CppunitTest_use_more_fonts,sw_core_docnode))
+
+# vim: set noet sw=4 ts=4:
diff --git a/sw/Module_sw.mk b/sw/Module_sw.mk
index a3958d4c4b65..280d7f25627c 100644
--- a/sw/Module_sw.mk
+++ b/sw/Module_sw.mk
@@ -107,6 +107,7 @@ $(eval $(call gb_Module_add_slowcheck_targets,sw,\
     CppunitTest_sw_unowriter \
     CppunitTest_sw_core_text \
     CppunitTest_sw_core_doc \
+    CppunitTest_sw_core_docnode \
     CppunitTest_sw_uibase_shells \
     CppunitTest_sw_uibase_dochdl \
     CppunitTest_sw_core_frmedt \
diff --git a/sw/qa/core/docnode/data/redline-ends-before-toc.docx b/sw/qa/core/docnode/data/redline-ends-before-toc.docx
new file mode 100644
index 000000000000..7696b3532e6e
--- /dev/null
+++ b/sw/qa/core/docnode/data/redline-ends-before-toc.docx
diff --git a/sw/qa/core/docnode/docnode.cxx b/sw/qa/core/docnode/docnode.cxx
new file mode 100644
index 000000000000..6ed3f8ec01f6
--- /dev/null
+++ b/sw/qa/core/docnode/docnode.cxx
@@ -0,0 +1,50 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <swmodeltestbase.hxx>
+
+#include <IDocumentRedlineAccess.hxx>
+#include <doc.hxx>
+#include <docary.hxx>
+
+char const DATA_DIRECTORY[] = "/sw/qa/core/docnode/data/";
+
+/// Covers sw/source/core/docnode/ fixes.
+class Test : public SwModelTestBase
+{
+public:
+    SwDoc* createDoc(const char* pName = nullptr);
+};
+
+SwDoc* Test::createDoc(const char* pName)
+{
+    if (!pName)
+        loadURL("private:factory/swriter", nullptr);
+    else
+        load(DATA_DIRECTORY, pName);
+
+    SwXTextDocument* pTextDoc = dynamic_cast<SwXTextDocument*>(mxComponent.get());
+    CPPUNIT_ASSERT(pTextDoc);
+    return pTextDoc->GetDocShell()->GetDoc();
+}
+
+CPPUNIT_TEST_FIXTURE(Test, testRedlineEndsBeforeToC)
+{
+    // Load a document where a delete redline ends right before a ToC, then redlines are hidden at a
+    // layout level.
+    SwDoc* pDoc = createDoc("redline-ends-before-toc.docx");
+    const SwRedlineTable& rTable = pDoc->getIDocumentRedlineAccess().GetRedlineTable();
+    // Without the accompanying fix in place, this test would have resulted in an assertion failure
+    // in InsertCnt_(), because the start of the section was hidden, but not its end.
+    CPPUNIT_ASSERT_EQUAL(static_cast<SwRedlineTable::size_type>(2), rTable.size());
+}
+
+CPPUNIT_PLUGIN_IMPLEMENT();
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/sw/source/core/docnode/ndsect.cxx b/sw/source/core/docnode/ndsect.cxx
index 8c2efee0eb7e..f53ae5d4e5cd 100644
--- a/sw/source/core/docnode/ndsect.cxx
+++ b/sw/source/core/docnode/ndsect.cxx
@@ -822,6 +822,29 @@ SwSectionNode* SwNodes::InsertTextSection(SwNodeIndex const& rNdIdx,
 
     SwSectionNode *const pSectNd =
             new SwSectionNode(aInsPos, rSectionFormat, pTOXBase);
+
+    if (lcl_IsTOXSection(rSectionData))
+    {
+        // We're inserting a ToX. Make sure that if a redline ends right before the ToX start, then
+        // that end now doesn't cross a section start node.
+        SwRedlineTable& rRedlines = GetDoc()->getIDocumentRedlineAccess().GetRedlineTable();
+        for (SwRedlineTable::size_type nIndex = 0; nIndex < rRedlines.size(); ++nIndex)
+        {
+            SwRangeRedline* pRedline = rRedlines[nIndex];
+            if (!pRedline->HasMark() || pRedline->GetMark()->nNode != aInsPos)
+            {
+                continue;
+            }
+
+            // The redline ends at the new section content start, so it originally ended before the
+            // section start: move it back.
+            SwPaM aRedlineEnd(*pRedline->GetMark());
+            aRedlineEnd.Move(fnMoveBackward);
+            *pRedline->GetMark() = *aRedlineEnd.GetPoint();
+            break;
+        }
+    }
+
     if( pEnde )
     {
         // Special case for the Reader/Writer