nsh with CLE and background tasks

[slorquet]

Trying to test the behaviour of CLE with the new code for character position.
I tried this command:

nsh>echo "abcd" &

to write output in the background and observe the cursor position for CLE.

However this does not really behave as expected and I cant explain what I see;

nsh> echo "abcd" &
echo [29:100]
nsh> h_child: BG echo
[6nabcd
child: BG echo complete

<type return, this does nothing>
<repeat that several times>
<finally try CTRL-C>
nsh: nsh_session: cle failed: 22
nsh>

Can you please investigate this? you can reproduce it directly in nsh with a simle "echo".

Configuring readline instead of CLE does not show this "lock" behaviour:

nsh> echo abcd &
echo [13:100]
nsh> h_child: BG echo
[Kabcd
child: BG echo complete
<type return>
nsh>

[no1wudi]

@slorquet I meet some display issue like:

NuttShell (NSH) NuttX-12.0.0
nsh> echo "test" &
echo [2:100]
nsh> test
7;6R
nsh>

But these issue disappered with #1650, you can try it.

NuttShell (NSH) NuttX-12.0.0
nsh> echo "test" &
echo [2:100]
nsh> test

nsh>