taht's the whole point of null coalescing operator

Well, in this case the notice is being reported, that still don't have much sense for me.

<?php
function bar()
{
    trigger_error("foo", E_USER_NOTICE);
    
    return null;
}
var_dump(bar()??false);

Here is an equivalent codes with diferent behavior

<?php
function bar()
{
    return false[''];
}
var_dump(bar()??false);
?>

<?php
var_dump(false['']??false);
?>

you can't seriously compare that becaus ethe case is completly wrong

trigger_error("foo", E_USER_NOTICE); has nothing to do with "null coalescing operator" at all, you call the function and the function does what it is supposed to do, throw a E_USER_NOTICE

why do you think "null coalescing operator" is involved here at all?
teh function returns NULL and "bar()??false" does what it is supposed to do

<?php
function bar()
{
    return false[''];
}
?>

this has again *nothing* to do with "null coalescing operator" because you are not using it at all, that way you would usie it

<?php
function bar()
{
    return false[''] ?? NULL;
}

that all looks like lack of understand php basics
?>

Well, just close the report if you want.
But I thought that all this cases should have the same behavior, while in the last line the error isn't being reported.
If is the expected behavior just close this.

<?php
function bar()
{
    return false[''];
}
bar();
false[''];

bar()??false;
false['']??false;

> But I thought that all this cases should have the same behavior

they have but you compare different cases

-------------------

Notice: Trying to access array offset on value of type bool in /mnt/data/downloads/test.php on line 4

line 4 don't use coalescing operator at all
return false[''];

-------------------

Notice: Trying to access array offset on value of type bool in /mnt/data/downloads/test.php on line 7

line 7 don't use coalescing operator at all
false[''];

-------------------

this is line 9 and don#t throw a warning
bar()??false;

Notice: Trying to access array offset on value of type bool in /mnt/data/downloads/test.php on line 4

would you mind which line trhows the error?
it happens inside line 4 again which *does not use* null coalescing operator at all

this would be your last example using null coalescing operator
again: lack of basic understanding how php works!

<?php
function bar()
{
  return false[''] ?? NULL;
}
bar();
false[''] ?? NULL;

bar()??false;
false['']??false;

expected behavior