diff --git a/libjava/ChangeLog b/libjava/ChangeLog
index c17af7b7a8c..579ee763451 100644
--- a/libjava/ChangeLog
+++ b/libjava/ChangeLog
@@ -1,3 +1,21 @@
+2005-02-12  Mark Wielaard  <mark@klomp.org>
+
+	Fixes bug libgcj/8170
+	* java/lang/ClassLoader.java (loadClass): Don't rewrap
+	ClassNotFoundException.
+	* gnu/java/lang/MainThread.java (run): Chain NoClassDefFoundError.
+	* gnu/gcj/runtime/NameFinder.java (remove_interpreter): Removed.
+	(remove_internal): New field superceding remove_interpreter.
+	(sanitizeStack): Remove all no-package classes starting with "_Jv_".
+	Remove no-class methods starting with "_Jv_". And Replace null
+	class or method names with the empty string. Stop at either the
+	MainThread or a real Thread run() method.
+	(newElement): Made static.
+	* java/net/URLClassLoader.java (findClass): Throw
+	ClassNotFoundExceptions including urls, plus parent using toString().
+	(thisString): New field.
+	(toString): New method.
+
 2005-02-10  Tom Tromey  <tromey@redhat.com>
 
 	* external/sax/Makefile.in: Rebuilt.
diff --git a/libjava/gnu/gcj/runtime/NameFinder.java b/libjava/gnu/gcj/runtime/NameFinder.java
index 024a6eeb232..b14bbf93327 100644
--- a/libjava/gnu/gcj/runtime/NameFinder.java
+++ b/libjava/gnu/gcj/runtime/NameFinder.java
@@ -37,8 +37,8 @@ import java.io.File;
  *     Whether calls to unknown functions (class and method names are unknown)
  *     should be removed from the stack trace. Only done when the stack is
  *     sanitized.</ul>
- * <ul><code>gnu.gcj.runtime.NameFinder.remove_interpreter</code>
- *     Whether runtime interpreter calls (methods in the _Jv_InterpMethod class
+ * <ul><code>gnu.gcj.runtime.NameFinder.remove_internal</code>
+ *     Whether runtime internal calls (methods in the internal _Jv_* classes
  *     and functions starting with 'ffi_') should be removed from the stack
  *     trace. Only done when the stack is sanitized.</ul>
  * <ul><code>gnu.gcj.runtime.NameFinder.use_addr2line</code>
@@ -72,10 +72,18 @@ public class NameFinder
 	  = Boolean.valueOf(System.getProperty
 		("gnu.gcj.runtime.NameFinder.remove_unknown", "true")
 	    ).booleanValue();
-  private static final boolean remove_interpreter
-	  = Boolean.valueOf(System.getProperty
+
+  // The remove_interpreter name is an old 3.3/3.4 (deprecated) synonym.
+  private static final boolean remove_internal
+	  = (Boolean.valueOf(System.getProperty
+		("gnu.gcj.runtime.NameFinder.remove_internal", "true")
+			     ).booleanValue()
+	     ||
+	     Boolean.valueOf(System.getProperty
 		("gnu.gcj.runtime.NameFinder.remove_interpreter", "true")
-	    ).booleanValue();
+                             ).booleanValue()
+	     );
+
   private static final boolean use_addr2line
 	  = Boolean.valueOf(System.getProperty
 		("gnu.gcj.runtime.NameFinder.use_addr2line", "true")
@@ -280,7 +288,7 @@ public class NameFinder
       consName = className.substring(lastDot + 1) + '(';
 
     int unknown = 0;
-    int interpreter = 0;
+    int internal = 0;
     int last_throw = -1;
     int length = elements.length;
     int end = length-1;
@@ -300,19 +308,23 @@ public class NameFinder
 		|| MName.startsWith("fillInStackTrace("))))
 	  {
 	    last_throw = i;
-	    // Reset counting of unknown and interpreter frames.
+	    // Reset counting of unknown and internal frames.
 	    unknown = 0;
-	    interpreter = 0;
+	    internal = 0;
 	  }
 	else if (remove_unknown && CName == null 
 		 && (MName == null || MName.startsWith("0x")))
 	  unknown++;
-	else if (remove_interpreter
+	else if (remove_internal
 		 && ((CName == null
 		      && MName != null && MName.startsWith("ffi_"))
-		     || (CName != null && CName.equals("_Jv_InterpMethod"))))
-	  interpreter++;
-	else if ("main(java.lang.String[])".equals(MName))
+		     || (CName != null && CName.startsWith("_Jv_"))
+		     || (CName == null && MName != null
+			 && MName.startsWith("_Jv_"))))
+	  internal++;
+	else if (("java.lang.Thread".equals(CName)
+		  || "gnu.java.lang.MainThread".equals(CName))
+		 && "run()".equals(MName))
 	  {
 	    end = i;
 	    break;
@@ -321,11 +333,11 @@ public class NameFinder
     int begin = last_throw+1;
 
     // Now filter out everything at the start and the end that is not part
-    // of the "normal" user program including any elements that are interpreter
+    // of the "normal" user program including any elements that are internal
     // calls or have no usefull information whatsoever.
     // Unless that means we filter out all info.
-    int nr_elements = end-begin-unknown-interpreter+1;
-    if ((begin > 0 || end < length-1 || unknown > 0 || interpreter > 0)
+    int nr_elements = end - begin - unknown - internal + 1;
+    if ((begin > 0 || end < length-1 || unknown > 0 || internal > 0)
 	&& nr_elements > 0)
       {
 	stack = new StackTraceElement[nr_elements];
@@ -337,14 +349,27 @@ public class NameFinder
 	    if (remove_unknown && CName == null 
 		 && (MName == null || MName.startsWith("0x")))
 	      ; // Skip unknown frame
-	    else if (remove_interpreter
+	    else if (remove_internal
 		     && ((CName == null
-			 && MName != null && MName.startsWith("ffi_"))
-			|| (CName != null && CName.equals("_Jv_InterpMethod"))))
-	      ; // Skip interpreter runtime frame
+			  && MName != null && MName.startsWith("ffi_"))
+			 || (CName != null && CName.startsWith("_Jv_"))
+			 || (CName == null && MName != null
+			     && MName.startsWith("_Jv_"))))
+	      ; // Skip internal runtime frame
 	    else
 	      {
-		stack[pos] = elements[i];
+		// Null Class or Method name in elements are not allowed.
+		if (MName == null || CName == null)
+		  {
+		    MName = MName == null ? "" : MName;
+		    CName = CName == null ? "" : CName;
+		    stack[pos] = newElement(elements[i].getFileName(),
+					    elements[i].getLineNumber(),
+					    CName, MName,
+					    elements[i].isNativeMethod());
+		  }
+		else
+		  stack[pos] = elements[i];
 		pos++;
 	      }
 	  }
@@ -359,11 +384,11 @@ public class NameFinder
    * Native helper method to create a StackTraceElement. Needed to work
    * around normal Java access restrictions.
    */
-  native private StackTraceElement newElement(String fileName,
-                                              int lineNumber,
-                                              String className,
-                                              String methName,
-                                              boolean isNative);
+  native static private StackTraceElement newElement(String fileName,
+						     int lineNumber,
+						     String className,
+						     String methName,
+						     boolean isNative);
 
   /**
    * Creates a StackTraceElement given a string and a filename.
diff --git a/libjava/gnu/java/lang/MainThread.java b/libjava/gnu/java/lang/MainThread.java
index 5937b870d3e..14a00ca8d9b 100644
--- a/libjava/gnu/java/lang/MainThread.java
+++ b/libjava/gnu/java/lang/MainThread.java
@@ -95,7 +95,9 @@ final class MainThread extends Thread
 	  }
 	catch (ClassNotFoundException x)
 	  {
-	    throw new NoClassDefFoundError(klass_name);
+	    NoClassDefFoundError ncdfe = new NoClassDefFoundError(klass_name);
+	    ncdfe.initCause(x);
+	    throw ncdfe;
 	  }
       }
 
diff --git a/libjava/java/lang/ClassLoader.java b/libjava/java/lang/ClassLoader.java
index 71f41c1cf1b..46e523c6834 100644
--- a/libjava/java/lang/ClassLoader.java
+++ b/libjava/java/lang/ClassLoader.java
@@ -288,8 +288,6 @@ public abstract class ClassLoader
     if (c != null)
       return c;
 
-    ClassNotFoundException ex = null;
-
     // Can the class be loaded by a parent?
     try
       {
@@ -306,20 +304,9 @@ public abstract class ClassLoader
       }
     catch (ClassNotFoundException e)
       {
-	ex = e;
       }
     // Still not found, we have to do it ourself.
-    try
-      {
-	c = findClass(name);
-      }
-    catch (ClassNotFoundException cause)
-      {
-	if (ex != null)
-	  throw new ClassNotFoundException(ex.toString(), cause);
-	else
-	  throw cause;
-      }
+    c = findClass(name);
     if (resolve)
       resolveClass(c);
     return c;
diff --git a/libjava/java/net/URLClassLoader.java b/libjava/java/net/URLClassLoader.java
index 3efc5dca76f..0da6a0356b2 100644
--- a/libjava/java/net/URLClassLoader.java
+++ b/libjava/java/net/URLClassLoader.java
@@ -1,5 +1,6 @@
 /* URLClassLoader.java --  ClassLoader that loads classes from one or more URLs
-   Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005
+   Free Software Foundation, Inc.
 
 This file is part of GNU Classpath.
 
@@ -958,7 +959,7 @@ public class URLClassLoader extends SecureClassLoader
 	resource = loader.getResource(resourceName);
       }
     if (resource == null)
-      throw new ClassNotFoundException(className + " not found in " + urls);
+      throw new ClassNotFoundException(className + " not found in " + this);
 
     // Try to read the class data, create the CodeSource, Package and
     // construct the class (and watch out for those nasty IOExceptions)
@@ -1039,9 +1040,43 @@ public class URLClassLoader extends SecureClassLoader
       }
     catch (IOException ioe)
       {
-        throw new ClassNotFoundException(className, ioe);
+	ClassNotFoundException cnfe;
+	cnfe = new ClassNotFoundException(className + " not found in " + this);
+	cnfe.initCause(ioe);
+	throw cnfe;
       }
   }
+  
+  // Cached String representation of this URLClassLoader
+  private String thisString;
+  
+  /**
+   * Returns a String representation of this URLClassLoader giving the
+   * actual Class name, the URLs that are searched and the parent
+   * ClassLoader.
+   */
+  public String toString()
+  {
+    if (thisString == null)
+      {
+	StringBuffer sb = new StringBuffer();
+	sb.append(this.getClass().getName());
+	sb.append("{urls=[" );
+	URL[] thisURLs = getURLs();
+	for (int i = 0; i < thisURLs.length; i++)
+	  {
+	    sb.append(thisURLs[i]);
+	    if (i < thisURLs.length - 1)
+	      sb.append(',');
+	  }
+	sb.append(']');
+	sb.append(", parent=");
+	sb.append(getParent());
+	sb.append('}');
+	thisString = sb.toString();
+      }
+    return thisString;
+  }
 
   /**
    * Finds the first occurrence of a resource that can be found. The locations