fixing SLF4J-337

jul-to-slf4j/src/main/java/org/slf4j/bridge/SLF4JBridgeHandler.java

@@ -261,7 +261,13 @@ public class SLF4JBridgeHandler extends Handler {
         // avoid formatting when there are no or 0 parameters. see also
         // http://jira.qos.ch/browse/SLF4J-203
         if (params != null && params.length > 0) {
-            message = MessageFormat.format(message, params);
+            try {
+                message = MessageFormat.format(message, params);
+            } catch (IllegalArgumentException e) {
+                // default to the same behavior as in java.util.logging.Formatter.formatMessage(LogRecord)
+                // see also http://jira.qos.ch/browse/SLF4J-337
+                return message;
+            }
         }
         return message;
     }

jul-to-slf4j/src/test/java/org/slf4j/bridge/SLF4JBridgeHandlerTest.java

@@ -178,6 +178,19 @@ public class SLF4JBridgeHandlerTest  {
         assertEquals(msg, le.getMessage());
     }
 
+    // See http://jira.qos.ch/browse/SLF4J-337
+        
+    @Test
+    public void illFormattedInputShouldBeReturnedAsIs() {
+        SLF4JBridgeHandler.install();
+        String msg = "foo {18=bad} {0}";
+        
+        julLogger.log(Level.INFO, msg, "ignored parameter due to IllegalArgumentException");
+        assertEquals(1, listAppender.list.size());
+        LoggingEvent le = (LoggingEvent) listAppender.list.get(0);
+        assertEquals(msg, le.getMessage());
+    }
+    
     void assertLevel(int index, org.apache.log4j.Level expectedLevel) {
         LoggingEvent le = (LoggingEvent) listAppender.list.get(index);
         assertEquals(expectedLevel, le.getLevel());

slf4j-site/src/site/pages/news.html

@@ -31,12 +31,19 @@
 
    <h3>, 2015 - Release of SLF4J 1.7.13</h3>
 
-   <p>Fixed issue with BasicMDCAdapter leaking MDC information to
-   non-child threads. This problem was reported by Lukasz Cwik in <a
+   <p>Fixed issue with <code>BasicMDCAdapter</code> leaking MDC
+   information to non-child threads. This problem was reported by
+   Lukasz Cwik in <a
    href="http://jira.qos.ch/browse/SLF4J-316">SLF4J-316</a> who also
    provided the relavant pull request.
    </p>
    
+   <p>More robust handling of ill-formatted input strings by
+   SLF4JBridgeHandler. This issue was reported in <a
+   href="http://jira.qos.ch/browse/SLF4J-337">SLF4J-337</a> by Rodolfo
+   Udo Labsch.
+   </p>
+
    <p>House cleaning of our project's Maven <em>pom.xml</em> files, an
    initiative undertaken by Jeremy Landis.
    </p>