Fix for 22356.

bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IMarker.java

diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IMarker.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IMarker.java
index e09f315..9301d6a 100644
--- a/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IMarker.java
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IMarker.java
@@ -365,7 +365,8 @@
  */
 public IResource getResource();
 /**
- * Returns the type of this marker.
+ * Returns the type of this marker. The returned marker type will not be 
+ * <code>null</code>.
  *
  * @return the type of this marker
  * @exception CoreException if this method fails. Reasons include:

bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IResource.java

diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IResource.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IResource.java
index 8802dc2..ce2ec72 100644
--- a/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IResource.java
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IResource.java
@@ -562,7 +562,7 @@
  * Creates and returns the marker with the specified type on this resource.
  * Marker type ids are the id of an extension installed in the
  * <code>org.eclipse.core.resources.markers</code> extension
- * point.
+ * point. The specified type string must not be <code>null</code>.
  *
  * @param type the type of the marker to create
  * @return the handle of the new marker