How can Z͎̠͗ͣḁ̵͙̑l͖͙̫̲̉̃ͦ̾͊ͬ̀g͔̤̞͓̐̓̒̽o͓̳͇̔ͥ text be prevented?

Question

I\'ve read about how Zalgo text works, and I\'m looking to learn how a chat or forum software could prevent that kind of annoyance. More precisely, what is the complete set

Answer 1

Make the box overflow:hidden. It doesn't actually disable Zalgo text, but it prevents it from damaging other comments.

.comment {
  /* the overflow: hidden is what prevents one comment's combining marks from affecting its siblings */
  overflow: hidden;
  /* the padding gives space for any legitimate combining marks */
  padding: 0.5em;
  /* the rest are just to visually divide the three comments */
  border: solid 1px #ccc;
  margin-top: -1px;
  margin-bottom: -1px;
}

The below comment looks awful.
H̡̫̤ͭ̓̓̇͗̎̀ơ̯̗͒̄̀̈ͤ̀͡w͓̲͙͋ͬ̊ͦ̂̀̚ ͎͉͖̌ͯͅͅd̳̘̿̃̔̏ͣ͂̉̕ŏ̖̙͋ͤ̊͗̓͟͜e͈͕̯̮͌ͭ̍̐̃͒s͙͔̺͇̗̱̿̊̇͞ ̸ͩͩ͑̋̀ͮͥͦ̊Z̆̊͊҉҉̠̱̦̩͕ą̟̹͈̺̹̋̅ͯĺ̡̘̹̻̩̩͋͘g̪͚͗ͬ͒o̢̖͇̬͍͇̔͋͊̓ ̢͈͂ͣ̏̿͐͂ͯ͠t̛͓̖̻̲ͤ̈ͣ͝e͋̄ͬ̽͜҉͚̭͇ͅx̌ͤ̓̂̓͐͐́͋͡ț̗̹̄̌̀ͧͩ̕͢ ̮̗̩̳̱̾w͎̭̤̄͗ͭ̃͗ͮ̐o̢̯̻̾ͣͬ̽̔̍͟r̢̪͙͍̠̀ͅǩ̵̶̗̮̮ͪ́?̙͉̥̬ͤ̌͗ͩ̕͡
The above comment looks awful.