Fix performance of QTextDocumentPrivate::adjustDocumentChangesAndCursors

As the changedCursors list grew large, the function used to spend an
extraordinate amount of time in QList::contains.

The fix removes the changedCursors list outright and replaces it with a
flag in QTextCursorPrivate.

Done-with: mae

1 files changed, 2 insertions, 3 deletions

diff --git a/src/gui/text/qtextdocument_p.h b/src/gui/text/qtextdocument_p.h
index 06e0753..dcac99d 100644
--- a/src/gui/text/qtextdocument_p.h
+++ b/src/gui/text/qtextdocument_p.h
@@ -277,7 +277,7 @@ public:
     void documentChange(int from, int length);
 
     inline void addCursor(QTextCursorPrivate *c) { cursors.append(c); }
-    inline void removeCursor(QTextCursorPrivate *c) { cursors.removeAll(c); changedCursors.removeAll(c); }
+    inline void removeCursor(QTextCursorPrivate *c) { cursors.removeAll(c); }
 
     QTextFrame *frameAt(int pos) const;
     QTextFrame *rootFrame() const;
@@ -329,8 +329,7 @@ private:
     BlockMap blocks;
     int initialBlockCharFormatIndex;
 
-    QList<QTextCursorPrivate*> cursors;
-    QList<QTextCursorPrivate*> changedCursors;
+    QList<QTextCursorPrivate *> cursors;
     QMap<int, QTextObject *> objects;
     QMap<QUrl, QVariant> resources;
     QMap<QUrl, QVariant> cachedResources;