RFR: 8328977 : JEditorPane.setPage not thread-safe, pageLoader not cancelled [v3]

[Alexey Ivanov]

On Fri, 19 Apr 2024 14:53:09 GMT, Renjith Kannath Pariyangad <rkannathpari at openjdk.org> wrote:

>> Hi Reviewers,
>> 
>> Added pageloader cancel before new page creation along with code restructuring. Moved all page loading calls inside synchronize to make it thread safe.
>> 
>> Regards,
>> Renjith.
>
> Renjith Kannath Pariyangad has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Rearranged if based on suggesion

There are lots of failures with the message: _java.lang.NullPointerException: Cannot invoke "java.net.URL.getProtocol()" because "u2" is null_

For example, the `javax/swing/JEditorPane/4492274/bug4492274.java` test fails with the following stack traces:


----------System.err:(32/2233)----------
java.lang.reflect.InvocationTargetException
	at java.desktop/java.awt.EventQueue.invokeAndWait(EventQueue.java:1312)
	at java.desktop/java.awt.EventQueue.invokeAndWait(EventQueue.java:1287)
	at java.desktop/javax.swing.SwingUtilities.invokeAndWait(SwingUtilities.java:1474)
	at bug4492274.main(bug4492274.java:50)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
	at java.base/java.lang.reflect.Method.invoke(Method.java:565)
	at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
	at java.base/java.lang.Thread.run(Thread.java:1447)
Caused by: java.lang.RuntimeException: java.lang.NullPointerException: Cannot invoke "java.net.URL.getProtocol()" because "u2" is null
	at bug4492274.createAndShowGUI(bug4492274.java:113)
	at bug4492274$1.run(bug4492274.java:53)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
	at …
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
Caused by: java.lang.NullPointerException: Cannot invoke "java.net.URL.getProtocol()" because "u2" is null
	at java.base/java.net.URLStreamHandler.sameFile(URLStreamHandler.java:413)
	at java.base/java.net.URL.sameFile(URL.java:1123)
	at java.desktop/javax.swing.JEditorPane.setPage(JEditorPane.java:478)
	at bug4492274.createAndShowGUI(bug4492274.java:104)
	... 10 more

src/java.desktop/share/classes/javax/swing/JEditorPane.java line 480:

> 478:         final String reference = page.getRef();
> 479: 
> 480:         if ((postData == null) && page.sameFile(loaded)) {

This line of code causes lots of test failures because `page.sameFile(loaded)` doesn't accept a `null` parameter, which results in `NullPointerException`.

-------------

Changes requested by aivanov (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/18670#pullrequestreview-2595528235
PR Review Comment: https://git.openjdk.org/jdk/pull/18670#discussion_r1942776674