Chris Down a9aa0d8ffb dwm: Fix getatomprop regression from heap overflow fix ...

Commit 244fa852fe ("dwm: Fix heap buffer overflow in getatomprop")
introduced a check for dl > 0 before dereferencing the property pointer.
However, I missed that the variable dl is passed to XGetWindowProperty
for both nitems_return and bytes_after_return parameters:

    XGetWindowProperty(..., &dl, &dl, &p)

The final value in dl is bytes_after_return, not nitems_return. For a
successfully read property, bytes_after is typically 0 (indicating all
data was retrieved), so the check `dl > 0` is always false and dwm never
reads any atom properties. So this is safe, but not very helpful :-)

dl is probably just a dummy variable anyway, so fix by using a separate
variable for nitems, and check nitems > 0 as originally intended.

2026-01-16 14:13:51 +01:00

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