hg: jdk/client: 4954348: JPGWriter.getNumThumbnailsSupported does not return -1 when passing null values

[prahalad.kumar.narayanan at oracle.com]

Changeset: 3c68768d3904
Author:    pnarayanan
Date:      2018-03-29 12:03 +0530
URL:       http://hg.openjdk.java.net/jdk/client/rev/3c68768d3904

4954348: JPGWriter.getNumThumbnailsSupported does not return -1 when passing null values
Reviewed-by: prr, serb, jdv

! src/java.desktop/share/classes/com/sun/imageio/plugins/jpeg/JPEGImageWriter.java
+ test/jdk/javax/imageio/plugins/jpeg/JpegNumThumbnailsTest.java