Accept 429 as an indication of the rate limit

src/main/java/org/kohsuke/github/AbuseLimitHandler.java

@@ -89,7 +89,7 @@ public void onError(IOException e, HttpURLConnection uc) throws IOException {
         private long parseWaitTime(HttpURLConnection uc) {
             String v = uc.getHeaderField("Retry-After");
             if (v == null)
-                return 60 * 1000; // can't tell, return 1 min
+                return 61 * 1000; // can't tell, return 1 min plus 1 second for luck
 
             return Math.max(1000, Long.parseLong(v) * 1000);
         }

src/main/java/org/kohsuke/github/GitHubAbuseLimitHandler.java

@@ -29,7 +29,19 @@ public abstract class GitHubAbuseLimitHandler extends GitHubConnectorResponseErr
      */
     @Override
     boolean isError(@Nonnull GitHubConnectorResponse connectorResponse) {
-        return isForbidden(connectorResponse) && hasRetryOrLimitHeader(connectorResponse);
+        return isTooManyRequests(connectorResponse)
+                || (isForbidden(connectorResponse) && hasRetryOrLimitHeader(connectorResponse));
+    }
+
+    /**
+     * Checks if the response status code is TOO_MANY_REQUESTS (403).
+     *
+     * @param connectorResponse
+     *            the response from the GitHub connector
+     * @return true if the status code is TOO_MANY_REQUESTS
+     */
+    private boolean isTooManyRequests(GitHubConnectorResponse connectorResponse) {
+        return connectorResponse.statusCode() == TOO_MANY_REQUESTS;
     }
 
     /**

src/main/java/org/kohsuke/github/GitHubConnectorResponseErrorHandler.java

@@ -23,6 +23,17 @@
  */
 abstract class GitHubConnectorResponseErrorHandler {
 
+    /**
+     * The HTTP 429 Too Many Requests response status code indicates the user has sent too many requests in a given
+     * amount of time ("rate limiting").
+     *
+     * A Retry-After header might be included to this response indicating how long to wait before making a new request.
+     *
+     * Why is this hardcoded here? The HttpURLConnection class is missing the status codes above 415, so the constant
+     * needs to be sourced from elsewhere.
+     */
+    public static final int TOO_MANY_REQUESTS = 429;
+
     /**
      * Called to detect an error handled by this handler.
      *