diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/DirCacheCheckoutMaliciousPathTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/DirCacheCheckoutMaliciousPathTest.java
index d263f629a..b3219cddb 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/DirCacheCheckoutMaliciousPathTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/DirCacheCheckoutMaliciousPathTest.java
@@ -54,6 +54,7 @@
 import org.junit.Test;
 
 public class DirCacheCheckoutMaliciousPathTest extends RepositoryTestCase {
+
 	protected ObjectId theHead;
 	protected ObjectId theMerge;
 
@@ -230,8 +231,14 @@ public void testMaliciousPathDot() throws Exception {
 	}
 
 	@Test
-	public void testMaliciousPathEmpty() throws Exception {
-		((MockSystemReader) SystemReader.getInstance()).setCurrentPlatform();
+	public void testMaliciousPathEmptyUnix() throws Exception {
+		((MockSystemReader) SystemReader.getInstance()).setUnix();
+		testMaliciousPathBadFirstCheckout("", "no");
+	}
+
+	@Test
+	public void testMaliciousPathEmptyWindows() throws Exception {
+		((MockSystemReader) SystemReader.getInstance()).setWindows();
 		testMaliciousPathBadFirstCheckout("", "no");
 	}
 
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java
index dd9ee10bf..bd896864d 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java
@@ -1202,8 +1202,9 @@ private static boolean isValidPathSegment(CanonicalTreeParser t) {
 			// Space or period at end of file name is ignored by Windows.
 			// Treat this as a bad path for now. We may want to handle
 			// this as case insensitivity in the future.
-			if (raw[ptr - 1] == '.' || raw[ptr - 1] == ' ')
-				return false;
+			if (ptr > 0)
+				if (raw[ptr - 1] == '.' || raw[ptr - 1] == ' ')
+					return false;
 			int i;
 			// Bad names, eliminate suffix first
 			for (i = start; i < ptr; ++i)