REPORT_MOUSE_POSITION causes infinite loop

[H. Nanosecond]

Hello,

There seems to be a problem when using REPORT_MOUSE_POSITION,
which is supposed to report mouse movement.
(I have ncurses version 5.1.20000708 and gpm-19.3 and use
a linux console and an xterm)

Do mousemask(REPORT_MOUSE_POSITION, (mmask_t *) 0); and 
click the mouse button and ncurses goes into an infinite loop in kgetch.
A trace shows this over and over:

start twait: -1 milliseconds, mode: 3
get time: 0 msec
elapsed time: 1556 msec
end twait: returned 1 (0), remaining time -1 msec
read 1 characters
pushed 0x199 at 1
head = 0, tail = 1, peek = 0
char 0 = KEY_MOUSE
char 1 = '^@' = 0x00
char 2 = '^@' = 0x00
char 3 = '^@' = 0x00
char 4 = '^@' = 0x00
char 5 = '^@' = 0x00
char 6 = '^@' = 0x00
char 7 = '^@' = 0x00
char 8 = '^@' = 0x00
char 9 = '^@' = 0x00
peeking at 0


on the other hand 
mousemask(REPORT_MOUSE_POSITION | ALL_MOUSE_EVENTS, (mmask_t *) 0);
works ok, but doesn't report mouse movement.