Fix exponential behavior of QTextCursor::removeSelectedText

This is an improved version of 62db6c18c7f1f60819783ed5e1340e9fc09e072e

2 files changed, 16 insertions, 3 deletions

diff --git a/src/gui/text/qtextdocument_p.cpp b/src/gui/text/qtextdocument_p.cpp
index 9bcf8b4..54bf36b 100644
--- a/src/gui/text/qtextdocument_p.cpp
+++ b/src/gui/text/qtextdocument_p.cpp
@@ -205,6 +205,7 @@ QTextDocumentPrivate::QTextDocumentPrivate()
 
     undoEnabled = true;
     inContentsChange = false;
+    blockCursorAdjustment = false;
 
     defaultTextOption.setTabStop(80); // same as in qtextengine.cpp
     defaultTextOption.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
@@ -669,7 +670,14 @@ void QTextDocumentPrivate::remove(int pos, int length, QTextUndoCommand::Operati
 {
     if (length == 0)
         return;
+    blockCursorAdjustment = true;
     move(pos, -1, length, op);
+    blockCursorAdjustment = false;
+    foreach (QTextCursorPrivate *curs, cursors) {
+        if (curs->adjustPosition(pos, -length, op) == QTextCursorPrivate::CursorMoved) {
+            curs->changed = true;
+        }
+    }
 }
 
 void QTextDocumentPrivate::setCharFormat(int pos, int length, const QTextCharFormat &newFormat, FormatChangeMode mode)
@@ -1268,9 +1276,13 @@ void QTextDocumentPrivate::adjustDocumentChangesAndCursors(int from, int addedOr
     if (!editBlock)
         ++revision;
 
-    foreach (QTextCursorPrivate *curs, cursors) {
-        if (curs->adjustPosition(from, addedOrRemoved, op) == QTextCursorPrivate::CursorMoved) {
-            curs->changed = true;
+    if (blockCursorAdjustment)  {
+        ; // postpone, will be called again from QTextDocumentPrivate::remove()
+    } else {
+        foreach (QTextCursorPrivate *curs, cursors) {
+            if (curs->adjustPosition(from, addedOrRemoved, op) == QTextCursorPrivate::CursorMoved) {
+                curs->changed = true;
+            }
         }
     }
 
diff --git a/src/gui/text/qtextdocument_p.h b/src/gui/text/qtextdocument_p.h
index b9d5f5a..b46d01c 100644
--- a/src/gui/text/qtextdocument_p.h
+++ b/src/gui/text/qtextdocument_p.h
@@ -345,6 +345,7 @@ public:
     int maximumBlockCount;
     uint needsEnsureMaximumBlockCount : 1;
     uint inContentsChange : 1;
+    uint blockCursorAdjustment : 1;
     QSizeF pageSize;
     QString title;
     QString url;