[fixed] x64 crashes when encountering NTFS junctions with long targets (>=113 characters)
Posted: 22 Aug 2025 00:07
While browsing my zigbee2mqtt folder, XYplorer (x64 v27.90.0032) suddenly crashed without an error message.
After a lot of trial and error, I found that an NTFS junction with a long target >=113 characters caused the crash. Furthermore, EnableCustomFileIcons can make things worse.
How to replicate the issue:
1) Open a command prompt and create a junction with a 113 characters long target on C:\
2) Open a fresh installation of XYplorer x64 (v27.90.0032) and navigate to C:\
3) Hover the mouse cursor over the junction "test", or try to double-click "test"
=> XYplorer crashes
When custom file icons are enabled (EnableCustomFileIcons=1), XYplorer crashes already at step 2).
I also noticed that XYplorer doesn't show the target of any junction. When looking at a junction with a target <113 characters, hovering over it will show the info pop-up. But the "Junction Target:" is empty.
As a side note: It doesn't matter if the target actually exists or not. I verified that the "overlong" junction in my zigbee2mqtt folder points to a valid folder, and Windows Explorer does show its content without any errors. The junction name itself can be as long as possible (255 characters) without causing a crash.
After a lot of trial and error, I found that an NTFS junction with a long target >=113 characters caused the crash. Furthermore, EnableCustomFileIcons can make things worse.
How to replicate the issue:
1) Open a command prompt and create a junction with a 113 characters long target on C:\
Code: Select all
mklink /J c:\test "c:\aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"3) Hover the mouse cursor over the junction "test", or try to double-click "test"
=> XYplorer crashes
When custom file icons are enabled (EnableCustomFileIcons=1), XYplorer crashes already at step 2).
I also noticed that XYplorer doesn't show the target of any junction. When looking at a junction with a target <113 characters, hovering over it will show the info pop-up. But the "Junction Target:" is empty.
As a side note: It doesn't matter if the target actually exists or not. I verified that the "overlong" junction in my zigbee2mqtt folder points to a valid folder, and Windows Explorer does show its content without any errors. The junction name itself can be as long as possible (255 characters) without causing a crash.
Fixed in next beta.