Hangup in DirectoryDialog

[basilevs]

Describe the bug

NullPointerException: Cannot invoke "java.util.Optional.orElse(Object)" because the return value of "org.eclipse.swt.widgets.DirectoryDialog.openDialog()" is null
    at org.eclipse.swt.widgets.DirectoryDialog.open(DirectoryDialog.java:170)

To Reproduce
I received a P2 update prompt, agreed to download updates and immediately went to import project in a new PDE workspace. Eclipse went into a lock for approximately 10 minutes (I suspect the hangup would be shorted if I did not mash the "Browse" button), meanwhile I've recovered a log

eclipse.txt

Mac OS console.txt

2025-03-23 17:57:49.895361 (pid/4306/com.apple.appkit.xpc.openAndSavePanelService [4334]) <Notice>: exited due to exit(69)
2025-03-23 17:57:49.895372 (pid/4306/com.apple.appkit.xpc.openAndSavePanelService [4334]) <Notice>: service state: exited
2025-03-23 17:57:49.895378 (pid/4306/com.apple.appkit.xpc.openAndSavePanelService [4334]) <Notice>: internal event: EXITED, code = 0
2025-03-23 17:57:49.895383 (pid/4306/com.apple.appkit.xpc.openAndSavePanelService [4334]) <Notice>: job state = exited
2025-03-23 17:57:49.895407 (pid/4306 [eclipse]) <Notice>: service inactive: com.apple.appkit.xpc.openAndSavePanelService

I think this is some kind of dialog conflict - another dialog is either opened or closed very recently or right after the current one.

Expected behavior
No deadlock.

Screenshots

Environment:

1. Select the platform(s) on which the behavior is seen:

• • [] All OS
• • Windows
• • Linux
• • macOS

2. Additional OS info (e.g. OS version, Linux Desktop, etc)

installation.txt

3. JRE/JDK version
   java.vendor.version=Temurin-23.0.1+11

Version since
SWT version 3.129

Workaround (or) Additional context
Wait long enough

See also:

• Expose cancel state of FileDialog and DirectoryDialog #1026
• Expose cancel state of FileDialog #1005

[basilevs]

While this is next to impossible to reproduce, the problem is very clear:

eclipse.platform.swt/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/DirectoryDialog.java

Line 198 in 9b2ef91

return null;

For some reason OS.objc_msgSend(OS.class_NSOpenPanel, OS.sel_openPanel); has hanged up, then returned null.

[iloveeclipse]

@basilevs : could you provide a fix?

[basilevs]

@basilevs : could you provide a fix?

I don't know how to fix the deadlock. Better error reporting: #1956

[basilevs]

Hypothesis

This might be a leak. The NSOpenPanel should not be retained in macOS 10.7 and newer, but we do.
Using the Open and Save Panels