diff -r 601160d857ef -r 2974d3800eb1 src/share/classes/com/sun/tools/javac/util/AbstractLog.java
--- a/src/share/classes/com/sun/tools/javac/util/AbstractLog.java	Thu Oct 28 10:17:47 2010 -0700
+++ b/src/share/classes/com/sun/tools/javac/util/AbstractLog.java	Thu Oct 28 18:58:43 2010 -0700
@@ -30,6 +30,7 @@
 import javax.tools.JavaFileObject;
 
 import com.sun.tools.javac.code.Lint.LintCategory;
+import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
 import com.sun.tools.javac.util.JCDiagnostic.SimpleDiagnosticPosition;
 
@@ -103,6 +104,19 @@
         report(diags.error(source, wrap(pos), key, args));
     }
 
+    /** Report an error, unless another error was already reported at same
+     *  source position.
+     *  @param flag   A flag to set on the diagnostic
+     *  @param pos    The source position at which to report the error.
+     *  @param key    The key for the localized error message.
+     *  @param args   Fields of the error message.
+     */
+    public void error(DiagnosticFlag flag, int pos, String key, Object ... args) {
+        JCDiagnostic d = diags.error(source, wrap(pos), key, args);
+        d.setFlag(flag);
+        report(d);
+    }
+
     /** Report a warning, unless suppressed by the  -nowarn option or the
      *  maximum number of warnings has been reached.
      *  @param pos    The source position at which to report the warning.