fix ArrayIndexOutOfBoundsException from bug 84270

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/scanner2/Scanner2Test.java

@@ -2354,4 +2354,14 @@ public class Scanner2Test extends BaseScanner2Test
 	   validateEOF();
    }
    
+   public void testbug84270() throws Exception {
+	   Writer writer = new StringWriter();
+	   writer.write("#define h g( ~\n"); //$NON-NLS-1$
+	   writer.write("#define g f\n"); //$NON-NLS-1$
+	   writer.write("#define f(a) f(x * (a))\n"); //$NON-NLS-1$
+	   writer.write("h 5) \n"); //$NON-NLS-1$
+	   initializeScanner( writer.toString() );
+	   fullyTokenize();
+   }
+   
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner2/BaseScanner.java

@@ -3979,6 +3979,9 @@ abstract class BaseScanner implements IScanner {
         while (bufferPos[bufferStackPos] < limit) {
             skipOverWhiteSpace();
 
+            if( bufferPos[bufferStackPos] + 1 >= limit )
+            	break;
+            
             if (buffer[++bufferPos[bufferStackPos]] == ')') {
                 // end of macro
                 break;