Review-request: Fix copy+paste sections (bug 271029)

[Sebastian Sauer]

The problem is that on copy+paste text in Words we create ODF ouf of a 
fragment. That fragment can contains SectionEnd's without SectionStart's (or 
the other way around which would probably produce invalid XML? That case is 
not handled with this patch :-/ ). That results then in an assert. See bug 
271029 for more details.

Attached patch fixes the assert with the document attached to the bugreport. 
But I am not sure if it's complete cause, as I wrote above, we need to take 
also the inverse case into account somehow and I am atm not sure how. Maybe we 
can just write endElement()'s till the styleStack isEmpty or so?

diff --git a/libs/kotext/opendocument/KoTextWriter.cpp 
b/libs/kotext/opendocument/KoTextWriter.cpp
index a938aa0..b61e0d5 100644
--- a/libs/kotext/opendocument/KoTextWriter.cpp
+++ b/libs/kotext/opendocument/KoTextWriter.cpp
@@ -135,6 +135,7 @@ public:
         ,  splitEndBlockNumber(-1)
         ,  splitRegionOpened(false)
         ,  splitIdCounter(1)
+        ,  sectionLevel(0)
         ,  deleteMergeRegionOpened(false)
         ,  deleteMergeEndBlockNumber(-1)
     {
@@ -208,6 +209,7 @@ public:
     int splitEndBlockNumber;
     bool splitRegionOpened;
     bool splitIdCounter;
+    int sectionLevel;
 
     //For saving of delete-changes that result in a merge between two 
elements
     bool deleteMergeRegionOpened;
@@ -1676,6 +1678,7 @@ void KoTextWriter::Private::writeBlocks(QTextDocument 
*document, int from, int t
             QVariant v = format.property(KoParagraphStyle::SectionStart);
             KoSection* section = (KoSection*)(v.value<void*>());
             if (section) {
+                sectionLevel++;
                 section->saveOdf(context);
             }
         }
@@ -1731,7 +1734,8 @@ void KoTextWriter::Private::writeBlocks(QTextDocument 
*document, int from, int t
         if (format.hasProperty(KoParagraphStyle::SectionEnd)) {
             QVariant v = format.property(KoParagraphStyle::SectionEnd);
             KoSectionEnd* section = (KoSectionEnd*)(v.value<void*>());
-            if (section) {
+            if (section && sectionLevel >= 1) {
+                --sectionLevel;
                 section->saveOdf(context);
             }
         }