QStringListModel: fix moveRows()

QStringListMode::moveRows() had an issue when the destination was before
the source row.

Change-Id: Icf64e5b4cdd6a39faf3ba4ccc3883196b247ccbd
Reviewed-by: Luca Beldi <v.ronin@yahoo.it>
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 11 insertions, 12 deletions

diff --git a/src/corelib/itemmodels/qstringlistmodel.cpp b/src/corelib/itemmodels/qstringlistmodel.cpp
index a248cdcd38..9c87ff853a 100644
--- a/src/corelib/itemmodels/qstringlistmodel.cpp
+++ b/src/corelib/itemmodels/qstringlistmodel.cpp
@@ -301,24 +301,23 @@ bool QStringListModel::moveRows(const QModelIndex &sourceParent, int sourceRow,
 {
     if (sourceRow < 0
         || sourceRow + count - 1 >= rowCount(sourceParent)
-        || destinationChild <= 0
+        || destinationChild < 0
         || destinationChild > rowCount(destinationParent)
+        || sourceRow == destinationChild
         || sourceRow == destinationChild - 1
-        || count <= 0) {
+        || count <= 0
+        || sourceParent.isValid()
+        || destinationParent.isValid()) {
         return false;
     }
     if (!beginMoveRows(QModelIndex(), sourceRow, sourceRow + count - 1, QModelIndex(), destinationChild))
         return false;
-    /*
-    QList::move assumes that the second argument is the index where the item will end up to
-    i.e. the valid range for that argument is from 0 to QList::size()-1
-    QAbstractItemModel::moveRows when source and destinations have the same parent assumes that
-    the item will end up being in the row BEFORE the one indicated by destinationChild
-    i.e. the valid range for that argument is from 1 to QList::size()
-    For this reason we remove 1 from destinationChild when using it inside QList
-    */
-    destinationChild--;
-    const int fromRow = destinationChild < sourceRow ? (sourceRow + count - 1) : sourceRow;
+
+    int fromRow = sourceRow;
+    if (destinationChild < sourceRow)
+        fromRow += count - 1;
+    else
+        destinationChild--;
     while (count--)
         lst.move(fromRow, destinationChild);
     endMoveRows();