RFR: 8159055: ImageIcon.setImage can't handle null parameter [v3]

[ExE Boss]

On Fri, 13 Jun 2025 10:02:21 GMT, Prasanta Sadhukhan <psadhukhan at openjdk.org> wrote:

>> When trying to call 'icon.setImage(null);' where 'icon' is an instance of ImageIcon, a null pointer exception is thrown at runtime.
>> The code tried to get the `id` for that image and instantiates `MediaTracker` to associate the null image to that `id` and checks the status of loading this null image, removes the null image from the tracker and then tries to get the image width where it throws NPE as image is null.
>> 
>> It's better to not go through all MediaTracker usage and bail out initially itself for null image..
>
> Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update image instance before returning

src/java.desktop/share/classes/javax/swing/ImageIcon.java line 371:

> 369:      * Sets the image displayed by this icon.
> 370:      * A null image is ignored.
> 371:      * @param image the image

The `image` can be set to `null` to mean “no image”:
Suggestion:

     * Sets the image displayed by this icon.
     * @param image the image, may be null

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PR Review Comment: https://git.openjdk.org/jdk/pull/25767#discussion_r2148836518