Fix an Assert in QTextTable

The problem was caused by the fragment id being inserted
in front of a cell spanning over several rows instead of
the next logical cell (or fragment_end) in the cells structure.

Task-number: QTBUG-11282
Reviewed-by: Simon Hausmann
(cherry picked from commit b2a4c7f0142a48f60e7ec4fc5866917e3da8b7c3)

1 files changed, 24 insertions, 4 deletions

diff --git a/src/gui/text/qtexttable.cpp b/src/gui/text/qtexttable.cpp
index 5100176..e3985ce 100644
--- a/src/gui/text/qtexttable.cpp
+++ b/src/gui/text/qtexttable.cpp
@@ -754,19 +754,39 @@ void QTextTable::insertColumns(int pos, int num)
     QTextFormatCollection *c = p->formatCollection();
     p->beginEditBlock();
 
+    QList<int> extendedSpans;
     for (int i = 0; i < d->nRows; ++i) {
         int cell;
         if (i == d->nRows - 1 && pos == d->nCols)
             cell = d->fragment_end;
         else
             cell = d->grid[i*d->nCols + pos];
-        QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), cell);
-        QTextCharFormat fmt = c->charFormat(it->format);
         if (pos > 0 && pos < d->nCols && cell == d->grid[i*d->nCols + pos - 1]) {
             // cell spans the insertion place, extend it
-            fmt.setTableCellColumnSpan(fmt.tableCellColumnSpan() + num);
-            p->setCharFormat(it.position(), 1, fmt);
+            if (!extendedSpans.contains(cell)) {
+                QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), cell);
+                QTextCharFormat fmt = c->charFormat(it->format);
+                fmt.setTableCellColumnSpan(fmt.tableCellColumnSpan() + num);
+                p->setCharFormat(it.position(), 1, fmt);
+                d->dirty = true;
+                extendedSpans << cell;
+            }
         } else {
+            /* If the next cell is spanned from the row above, we need to find the right position
+            to insert to */
+            if (i > 0 && pos < d->nCols && cell == d->grid[(i-1) * d->nCols + pos]) {
+                int gridIndex = i*d->nCols + pos;
+                const int gridEnd = d->nRows * d->nCols - 1;
+                while (gridIndex < gridEnd && cell == d->grid[gridIndex]) {
+                    ++gridIndex;
+                }
+                if (gridIndex == gridEnd)
+                    cell = d->fragment_end;
+                else
+                    cell = d->grid[gridIndex];
+            }
+            QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), cell);
+            QTextCharFormat fmt = c->charFormat(it->format);
             fmt.setTableCellRowSpan(1);
             fmt.setTableCellColumnSpan(1);
             Q_ASSERT(fmt.objectIndex() == objectIndex());