Applying patch in asterisk 1.4.21

good day to all, im still new in asterisk and i would like to ask something for security purposes with regards to applying a patch. i have found a fixed patch for a bug with regards to mix monitor then i would like to patch it, but my question is does patching this one will not harm the running system or affects the other functionality?thank you so much.

Without knowing exactly which patch you are referring to, it is impossible to even guess.

Except for the most trivial of patches, I doubt that anyone will give you an absolute guarantee.

thank you so much david55, the patch im referring to is came from these bug issue of the mixmonitor (issues.asterisk.org/view.php?id=13538#bugnotes) i am just afraid to apply it because i am not the one who made the configuration of the running script. I am studying the existing configuration since the one who made it is already resigned. thank you so much for your help david55.