diff --git a/core/org.eclipse.cdt.core.tests/ChangeLog b/core/org.eclipse.cdt.core.tests/ChangeLog
index 1369cd845d2..4b390f921ed 100644
--- a/core/org.eclipse.cdt.core.tests/ChangeLog
+++ b/core/org.eclipse.cdt.core.tests/ChangeLog
@@ -1,3 +1,7 @@
+2003-09-30 Andrew Niefer
+	added testBug43503_AmbiguousUsing() and testBug43503_UnableToResolveFunction() to
+	ParserSymbolTableTest
+
 2003-09-29 Andrew Niefer
 	added testBug43062 and testConstructorDestructor to FunctionMethodPatternTests
 	modified resources/search/classDecl.cpp & include.h to include more operators and a constructor
diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ParserSymbolTableTest.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ParserSymbolTableTest.java
index ee484457dba..77daec870eb 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ParserSymbolTableTest.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ParserSymbolTableTest.java
@@ -2844,5 +2844,73 @@ public class ParserSymbolTableTest extends TestCase {
 		look = table.getCompilationUnit().unqualifiedFunctionLookup( "f", parameters );
 		assertEquals( look, f );
 	}
+	
+	/**
+	 * 
+	 * namespace A{
+	 *    void f();
+	 * }
+	 * namespace B{
+	 *    int f;
+	 * }
+	 * namespace C{
+	 *    using namespace A;
+	 *    using namespace B;
+	 *    using f;		//ambiguous, int f or void f()?
+	 * }
+	 */
+	public void testBug43503_AmbiguousUsing() throws Exception{
+		newTable();
+		IContainerSymbol NSA = table.newContainerSymbol( "A", TypeInfo.t_namespace );
+		table.getCompilationUnit().addSymbol( NSA );
+		
+		IParameterizedSymbol f1 = table.newParameterizedSymbol( "f", TypeInfo.t_function );
+		NSA.addSymbol( f1 );
+		
+		IContainerSymbol NSB = table.newContainerSymbol( "B", TypeInfo.t_namespace );
+		table.getCompilationUnit().addSymbol( NSB );
+		
+		ISymbol f2 = table.newSymbol( "f", TypeInfo.t_int );
+		NSB.addSymbol( f2 );
+		
+		IContainerSymbol NSC = table.newContainerSymbol( "C", TypeInfo.t_namespace );
+		table.getCompilationUnit().addSymbol( NSC );
+		NSC.addUsingDirective( NSA );
+		NSC.addUsingDirective( NSB );
+		
+		try{
+			NSC.addUsingDeclaration( "f" );
+			assertTrue( false );
+		} catch ( ParserSymbolTableException e ){
+			assertEquals( e.reason, ParserSymbolTableException.r_Ambiguous );
+		}
+	}
+	
+	/**
+	 * void f( void );
+	 * void f( int );
+	 * 
+	 * void * pF = &f;  //lookup without function parameters, should be ambiguous
+	 * @throws Exception
+	 */
+	public void testBug43503_UnableToResolveFunction() throws Exception{
+		newTable();
+		
+		IParameterizedSymbol f1 = table.newParameterizedSymbol( "f", TypeInfo.t_function );
+		
+		IParameterizedSymbol f2 = table.newParameterizedSymbol( "f", TypeInfo.t_function );
+		f2.addParameter( TypeInfo.t_int, 0, null, false );
+		
+		table.getCompilationUnit().addSymbol( f1 );
+		table.getCompilationUnit().addSymbol( f2 );
+		
+		try{
+			table.getCompilationUnit().lookup( "f" );
+			assertTrue( false );
+		} catch( ParserSymbolTableException e ){
+			assertEquals( e.reason, ParserSymbolTableException.r_UnableToResolveFunction );
+		}
+		
+	}
 }
 
diff --git a/core/org.eclipse.cdt.core/parser/ChangeLog b/core/org.eclipse.cdt.core/parser/ChangeLog
index 162ee34e444..a09e127f6a7 100644
--- a/core/org.eclipse.cdt.core/parser/ChangeLog
+++ b/core/org.eclipse.cdt.core/parser/ChangeLog
@@ -1,3 +1,10 @@
+2003-09-30 Andrew Niefer
+	PST changes for bug 43503 - parser needs to know the different between ambiguous functions
+	and no functions when no parameter information is provided
+	- throw r_UnableToResolveFunction if we have more than 1 function and no parameter info was given
+	- handle this case in addUsingDeclaration.
+	* note that r_UnableToResolveFunction doesn't necessarily mean ambiguous if we had enough information
+
 2003-09-29 Hoda Amer
 	Solution to bug#43679 : Exceptions in indexer 
 	
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/pst/ParserSymbolTable.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/pst/ParserSymbolTable.java
index bfe5016d2f2..869c4523184 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/pst/ParserSymbolTable.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/pst/ParserSymbolTable.java
@@ -657,7 +657,7 @@ public class ParserSymbolTable {
 					return (ISymbol) functionList.getFirst();
 				} else {
 					data.foundItems.addAll( functionList );
-					return null;
+					throw new ParserSymbolTableException( ParserSymbolTableException.r_UnableToResolveFunction );
 				}
 			} else {
 				return resolveFunction( data, functionList );
@@ -3074,7 +3074,14 @@ public class ParserSymbolTable {
 	
 			//figure out which declaration we are talking about, if it is a set of functions,
 			//then they will be in data.foundItems (since we provided no parameter info);
-			BasicSymbol obj = (BasicSymbol)ParserSymbolTable.resolveAmbiguities( data );
+			BasicSymbol obj = null;
+			try{
+				obj = (BasicSymbol)ParserSymbolTable.resolveAmbiguities( data );
+			} catch ( ParserSymbolTableException e ) {
+				if( e.reason != ParserSymbolTableException.r_UnableToResolveFunction ){
+					throw e;
+				}
+			}
 	
 			if( data.foundItems == null ){
 				throw new ParserSymbolTableException( ParserSymbolTableException.r_InvalidUsing );				
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/pst/ParserSymbolTableException.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/pst/ParserSymbolTableException.java
index 2250b26008b..b562e49fddc 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/pst/ParserSymbolTableException.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/pst/ParserSymbolTableException.java
@@ -44,6 +44,7 @@ public class ParserSymbolTableException extends Exception {
 	public static final int r_BadTemplate			=  4;
 	public static final int r_InvalidUsing			=  5;
 	public static final int r_BadVisibility			=  6;
+	public static final int r_UnableToResolveFunction = 7;
 	
 	public int reason = -1;
 }
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