Use QScopedValueRollback more as a reentrancy guard

It is documented for the use, but we were rarely using it.

Change-Id: I812b9e6c8fbf204aba43ce2b79eca308ca75de88
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 15 insertions, 12 deletions

diff --git a/src/gui/text/qsyntaxhighlighter.cpp b/src/gui/text/qsyntaxhighlighter.cpp
index 102a776ed3..cf584f6980 100644
--- a/src/gui/text/qsyntaxhighlighter.cpp
+++ b/src/gui/text/qsyntaxhighlighter.cpp
@@ -45,6 +45,7 @@
 #include <private/qtextdocument_p.h>
 #include <qtextlayout.h>
 #include <qpointer.h>
+#include <qscopedvaluerollback.h>
 #include <qtextobject.h>
 #include <qtextcursor.h>
 #include <qdebug.h>
@@ -68,14 +69,14 @@ public:
     void reformatBlocks(int from, int charsRemoved, int charsAdded);
     void reformatBlock(const QTextBlock &block);
 
-    inline void rehighlight(QTextCursor &cursor, QTextCursor::MoveOperation operation) {
-        inReformatBlocks = true;
+    inline void rehighlight(QTextCursor &cursor, QTextCursor::MoveOperation operation)
+    {
+        QScopedValueRollback<bool> bg(inReformatBlocks, true);
         cursor.beginEditBlock();
         int from = cursor.position();
         cursor.movePosition(operation);
         reformatBlocks(from, 0, cursor.position() - from);
         cursor.endEditBlock();
-        inReformatBlocks = false;
     }
 
     inline void _q_delayedRehighlight() {
diff --git a/src/gui/text/qtextdocument_p.cpp b/src/gui/text/qtextdocument_p.cpp
index c0a0c1a177..0e3c8d0e83 100644
--- a/src/gui/text/qtextdocument_p.cpp
+++ b/src/gui/text/qtextdocument_p.cpp
@@ -40,6 +40,7 @@
 #include <private/qtools_p.h>
 #include <qdebug.h>
 
+#include <qscopedvaluerollback.h>
 #include "qtextdocument_p.h"
 #include "qtextdocument.h"
 #include <qtextformat.h>
@@ -274,9 +275,10 @@ void QTextDocumentPrivate::clear()
         rtFrame = 0;
         init();
         cursors = oldCursors;
-        inContentsChange = true;
-        emit q->contentsChange(0, len, 0);
-        inContentsChange = false;
+        {
+            QScopedValueRollback<bool> bg(inContentsChange, true);
+            emit q->contentsChange(0, len, 0);
+        }
         if (lout)
             lout->documentChanged(0, len, 0);
     } QT_CATCH(...) {
@@ -309,9 +311,10 @@ void QTextDocumentPrivate::setLayout(QAbstractTextDocumentLayout *layout)
             it->free();
 
     emit q->documentLayoutChanged();
-    inContentsChange = true;
-    emit q->contentsChange(0, 0, length());
-    inContentsChange = false;
+    {
+        QScopedValueRollback<bool> bg(inContentsChange, true);
+        emit q->contentsChange(0, 0, length());
+    }
     if (lout)
         lout->documentChanged(0, 0, length());
 }
@@ -1213,9 +1216,8 @@ void QTextDocumentPrivate::finishEdit()
 
     if (lout && docChangeFrom >= 0) {
         if (!inContentsChange) {
-            inContentsChange = true;
+            QScopedValueRollback<bool> bg(inContentsChange, true);
             emit q->contentsChange(docChangeFrom, docChangeOldLength, docChangeLength);
-            inContentsChange = false;
         }
         lout->documentChanged(docChangeFrom, docChangeOldLength, docChangeLength);
     }
diff --git a/src/gui/text/qtextdocument_p.h b/src/gui/text/qtextdocument_p.h
index d95f5bef6a..a8e17bfc08 100644
--- a/src/gui/text/qtextdocument_p.h
+++ b/src/gui/text/qtextdocument_p.h
@@ -339,6 +339,7 @@ private:
     int lastBlockCount;
 
 public:
+    bool inContentsChange;
     QTextOption defaultTextOption;
     Qt::CursorMoveStyle defaultCursorMoveStyle;
 #ifndef QT_NO_CSSPARSER
@@ -346,7 +347,6 @@ public:
 #endif
     int maximumBlockCount;
     uint needsEnsureMaximumBlockCount : 1;
-    uint inContentsChange : 1;
     uint blockCursorAdjustment : 1;
     QSizeF pageSize;
     QString title;