[GTK] Double click behaviour changed between 2025-03 and 2025-09

[stephan-herrmann]

Describe the bug

As reported by @haubi in eclipse-egit/egit#110 a double click into the EGit Staging View may fail to select the element under the cursor, and will instead operate on the previously selected tree element.

Since EGit doesn't seem to have any recent related changes fingers are pointing to SWT for changed behavior.

To Reproduce

• Have a git staging view with several staged files
• Select the first file
• Select any editor or other view
• Perform a double click on the second file in the staging view

Expected behavior
A compare editor should open for the second file.

Actual behavior
Compare editor will open for the first file.

Environment:

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

• • All OS
• • Windows
• • Linux
• • macOS

EGit committer tried to reproduce on macOS and failed.

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

I'm seeing it on Ubuntu 24.04.3 with

org.eclipse.swt.internal.gtk.theme=Breeze:dark
org.eclipse.swt.internal.gtk.version=3.24.41
org.eclipse.swt.internal.webkitgtk.version=2.48.7
osgi.ws=gtk

and

GTK2_RC_FILES=/etc/gtk-2.0/gtkrc:/home/stephan/.gtkrc-2.0:/home/stephan/.config/gtkrc-2.0
GTK_OVERLAY_SCROLLING=0
GTK_RC_FILES=/etc/gtk/gtkrc:/home/stephan/.gtkrc:/home/stephan/.config/gtkrc
SWT_GTK3=1
SWT_GTK4=0

3. JRE/JDK version

java.version=24.0.1

Version since
Reported in eclipse-egit/egit#110:

• working: SWT 3.129.0.v20250221-1734
• broken: SWT 3.131.0.v20250820-1556

Workaround (or) Additional context

One additional click is required to first set focus to the staging view.

See eclipse-egit/egit#110