False positive in SLF4J_PLACE_HOLDER_MISMATCH when a runtime Throwable is passed to a compile time Object version of log.warn

[MateuszStefek]

In the case below, we intentionally select an overloaded version of the warn method that takes a single Object argument. The behaviour is different from the other overloads of Logger.warn (Object... arguments ) or (Throwable t).

The code is correct, but we receive a false positive.

    /**
     * Log a message at the WARN level according to the specified format
     * and argument.
     * <p/>
     * <p>This form avoids superfluous object creation when the logger
     * is disabled for the WARN level. </p>
     *
     * @param format the format string
     * @param arg    the argument
     */
    public void warn(String format, Object arg);

    /**
     * Log a message at the WARN level according to the specified format
     * and arguments.
     * <p/>
     * <p>This form avoids superfluous string concatenation when the logger
     * is disabled for the WARN level. However, this variant incurs the hidden
     * (and relatively small) cost of creating an <code>Object[]</code> before invoking the method,
     * even if this logger is disabled for WARN. The variants taking
     * {@link #warn(String, Object) one} and {@link #warn(String, Object, Object) two}
     * arguments exist solely in order to avoid this hidden cost.</p>
     *
     * @param format    the format string
     * @param arguments a list of 3 or more arguments
     */
    public void warn(String format, Object... arguments);

    /**
     * Log an exception (throwable) at the WARN level with an
     * accompanying message.
     *
     * @param msg the message accompanying the exception
     * @param t   the exception (throwable) to log
     */
    public void warn(String msg, Throwable t);

The first one never checks for the argument being a Throwable, and therefore the code is correct.

Version:

<plugin>
	<groupId>jp.skypencil.findbugs.slf4j</groupId>
	<artifactId>bug-pattern</artifactId>
	<version>1.5.0</version>
</plugin>