The comments in that function say "This only happens if master is a
slave device. don't do that" but static analysis doesn't respect that.
Found by Oracle Parfait 13.3:
Null pointer dereference [null-pointer-deref]:
Read from null pointer XTestptr
at line 274 of Xi/xichangehierarchy.c in function 'remove_master'.
Null pointer introduced at line 691 of Xext/xtest.c in function
'GetXTestDevice'.
Function GetXTestDevice may return constant 'NULL' at line 691,
called at line 273 of Xi/xichangehierarchy.c in function
'remove_master'.
Null pointer dereference [null-pointer-deref]:
Read from null pointer XTestkeybd
at line 279 of Xi/xichangehierarchy.c in function 'remove_master'.
Null pointer introduced at line 691 of Xext/xtest.c in function
'GetXTestDevice'.
Function GetXTestDevice may return constant 'NULL' at line 691,
called at line 278 of Xi/xichangehierarchy.c in function
'remove_master'.
Fixes: 0814f511d ("input: store the master device's ID in the devPrivate for XTest devices.")
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1730>
284ad8e473