adb47b7f73
The adjustment of block length with 'off-by-one' affects content length during undo operation. The issue occurs when we perform undo operation for a set of group blocks that have same fragment position. Since their positions are same, group block change (QTextDocumentPrivate::documentChange) with respect to insertion doesn't affect document block length and further adjustment to 'off-by-one' without considering this leads to incorrect document content change information (such as invalid information with regard to characters removed). This patch skips adjustment of group block length during undo operation. Amends 8fbedf2196a292fe2affcf83ddc846b9c852772a Fixes: QTBUG-113865 Pick-to: 6.5 6.2 5.15 Change-Id: I315dcf01ba5b2f4ed6d95e9d6910d82848374aef Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io> (cherry picked from commit 8a725084396da5872fa020212b3cb09ee40a91df) Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org> (cherry picked from commit 3999908ae5ea9e86b1785f7352d31fb11cc8d21e)