[136902] source validation slows down formatter
diff --git a/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/internal/reconcile/DocumentRegionProcessor.java b/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/internal/reconcile/DocumentRegionProcessor.java
index 80b3f9b..fe472cb 100644
--- a/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/internal/reconcile/DocumentRegionProcessor.java
+++ b/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/internal/reconcile/DocumentRegionProcessor.java
@@ -54,6 +54,7 @@
 
 	private final String SSE_UI_ID = "org.eclipse.wst.sse.ui"; //$NON-NLS-1$
 
+
 	protected void beginProcessing() {
 		super.beginProcessing();
 		ValidatorStrategy validatorStrategy = getValidatorStrategy();
@@ -165,7 +166,7 @@
 	 * @param dirtyRegion
 	 */
 	protected void process(DirtyRegion dirtyRegion) {
-		if (!isInstalled())
+		if (!isInstalled() || isInRewriteSession())
 			return;
 
 		super.process(dirtyRegion);