Bug 541678 - premature end of file error in new target editor

Fixes org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1;
Premature end of file.
	......
	at org.eclipse.pde.internal.core.target.TargetDefinitionPersistenceHelper.initFromXML(TargetDefinitionPersistenceHelper.java:164)

Change-Id: Ib05077d7b49d91d00c2802a450d9dc8d889edb87
Signed-off-by: Alexander Kurtakov <akurtako@redhat.com>
diff --git a/ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/target/TargetDefinitionPersistenceHelper.java b/ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/target/TargetDefinitionPersistenceHelper.java
index 228b69b..b33b4e1 100644
--- a/ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/target/TargetDefinitionPersistenceHelper.java
+++ b/ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/target/TargetDefinitionPersistenceHelper.java
@@ -154,6 +154,10 @@
 			}
 		} else {
 			stream = input.getFileStore().openInputStream(0, null);
+			if (stream.available() == 0) {
+				// do not process empty stream
+				return;
+			}
 		}
 		DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
 		parser.setErrorHandler(new DefaultHandler());