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The JVM crashes if given a shell with an active PopupDialog. A maintainer reported on #188317 that this is because PopupDialogs dispose themselves when they are deactivated. I'm attaching code that shows a PopupDialog successfully creating a ElementListSelectionDialog, but crashing the JVM when attempting to create a FileDialog.
Created attachment 70533 [details] Java class demonstrating the problem This class demonstrates the problem. Have a plugin or RCP app do "PopupDialog pop = new BugPopupDialog(new Shell()); pop.open();" to test.
SWT only test case: public static void main(String[] args) { final Display display = new Display(); final Shell shell = new Shell(display); Button buttonBrowse = new Button(shell, SWT.PUSH); //$NON-NLS-1$ buttonBrowse.setBounds(10, 10, 100, 40); buttonBrowse.setText("Browse..."); buttonBrowse.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { FileDialog fsd = new FileDialog(shell, SWT.SINGLE); String fname = fsd.open(); System.out.println(fname); } }); shell.addListener(SWT.Deactivate, new Listener() { public void handleEvent(Event event) { shell.dispose(); } }); shell.setBounds(200, 200, 300, 300); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) display.sleep(); } display.dispose(); }
I have a similar scenario which crashes the JVM on Linux GTK. Please see attached SWT-only code that reproduces the problem on Linux GTK. I open a shell that has styles SWT.ON_TOP | SWT.RESIZE applied to it and attach a shell listener listener to this shell. I then call close() and dispose() on the shell when I receive a deactivate event. On Windows, this works fine: when the user deactivates the shell, the shell is closed and disposed of. On Linux GTK, this crashes the JVM. On further investigation, the GTK shell code calls OS.gdk_window_invalidate_rect** right after sending the Deactivate event to listeners. However, since the shell has already been disposed of, this crashes the JVM. A workaround is to call dispose inside an asyncExec. But that is a hack which we are uncomfortable with. Perhaps the fix could be to check if shell has been disposed of before invalidating the shell? ** line 753 of Shell#filterProc(..) under the FocusOut switch case.
Created attachment 172161 [details] Snippet that crashes the JVM on Linux GTK Instructions: 1. Run the snippet 2. Click on the button 3. Click on the borderless shell that popups up to give it focus. 4. Click on the original parent shell with the button, to deactivate the child shell. JVM crashes.
This bug hasn't had any activity in quite some time. Maybe the problem got resolved, was a duplicate of something else, or became less pressing for some reason - or maybe it's still relevant but just hasn't been looked at yet. If you have further information on the current state of the bug, please add it. The information can be, for example, that the problem still occurs, that you still want the feature, that more information is needed, or that the bug is (for whatever reason) no longer relevant.
