Win 7, Chrome. That’s hilarious!
There’s a text generator for that, it allows up and down, but not diagonal. H̸̨̧͖̟̬̘̣̦̰̬̲͕̤͍͓͚ͦ͐ͣ̋́̅͊̓̏e̷͗̄̓̊ͨ̅͆ͦ͌͋ͥ̏̽̈͌̚͏̧̮̣̥̲̩̮͙̺̱̠͉̖͔l̡̧͎͙̟̗̦̞͉̈͒̊̔p̵̡̯̺̩̯̯̰͓͔̞̥͚̭̓ͬͭͨͨ͑ͫ̎ͩ̃ͣ̏͑̀͜!ͮͤͧ͆̊͌ͯ̄̃ͤ̍ͫ̆̕͡҉̬̜̭̝̝̬̯̳̘͟͠ ̶̱͉̣̬̟̭̜̱̝̝̙̼̣̺̜ͮ̏̔ͨͤ̐̇̋͛̉̍͋̂̐͋ͩ̇ͬ͟I̴̧̬̲͍͖̮̦̻̩̣͊̋ͨ͗̄́̉ͧ̌̿̽͑ͤͦ̅ͬͬ̚͘’̷̨̛̠̖̤̺̪͔͖͍̻͇͉̭̼̫ͦ͊ͮ̽ͯ̾̃̅ͬ͗͊̾̉̓͐ͧ͂ͅm̦͓̘͕̜̻̜̎̀͗̋ͤ̔ͧͮ̈̊͒̒̂̉ͤ̄̓͐̾͞ ̤͚̺͖̩͆ͧͨ̄͌͒͋ͬ̂͑̍̾̽ͤ̊̈́̂̎͡͝s̴̶̋ͦ͌̈̇̽͛̇̚͏͍̙̳͇̫̮̲̩̗̝͕̗͉̪͈̗͉̩̕͢ͅt̢̛ͧ͆ͦ͐̇̓́̒́ͪ̆ͧ͊ͩ̀͝҉̳͔̜̮u̵̸̢͙̙̪͓͓̔̀̏ͤ͋̾̉͛͟ͅc̵̙͚̮͊̌͌͆͗͐͗͆̂ͮͪ̍͛̀͟k̭̺̮̩̩̟͙̺̬͂ͭ̄ͩ̅ͬ͐͑̈̋͆̾̔͟͞ ͕̺̗̱̠̘̳̖̺̗͕͍̬ͨ̇̾͆̾͛͂̓ͭͬ̍̈̍̽̋ͭ͑̆̕͘í̵̶͉͕͉͈̫̠̭͚̝̳̭̰̘̥̺̠̰̯ͭ͑ͪͧ̔ͯ͑͢͡͡n̨͛̄̊̈́̏ͬ̽̚҉̟̜̜̠̭̣̙̳͔̠̭͍̲̼͖̹ ̶̷̷̵̲̜̹̠ͣ̍͛̏ͮ͛͌̉ͩ̓ͤͣ͆̎̍̒̚t̶̨͈̼͔̯̣̹̭̹͙̠̦̜̖̦͍͗̈́́̀͐͊̄ͤͭ̋̎̚͘͠ḩ̵̸̨̣̲͓͖̝̲̖͖̣͇̽̑̌̐ͬe̎͂̊̍̌ͨ̈ͭ̿̀ͥ̋ͩ͑̀͏̲͕̠̺̗̝͙̘̜̤͉̭̪̪̭͢͜ ̸̪͍̖̠̟̟̩̦̫̭̂̓̓̋͛̀͑ͧ͟͟͠ͅv̵̴̛̙̝̱͈̍̂ͪͪ͆̈́ͫ̒ͪ̒̔͆͞ͅo̵̵͇̘̮̤̙̤̭͐̋̏ͬ̊̐͂̂͑̎ͧ̾̊ͮͭ͢͠ͅi̜̙̥̬̹͓̯͙͈̬̺̜̮ͪ̍ͨ͆ͪ̄̅ͪͭ̃̈́͑́̀d̢̠͔̙͓͉̤̺̫̙̟̞̯̬͍̲̮͉̫ͪ̔̊!̛ͧ̈̉̈ͩ̾̒̍̿́̿̇̋̉ͤ̋̓͌͢͏҉̲̥͈̪̬̺͓̜̰̻̗͚̮ͅ Z͙͙̳̯̠ͨ̅́̕͡a̴͔͖͔̜̞̩̜ͫ̈ͭ̎͛ͧ͜l̨̨̮̺̘̻͔̙̿ͨͪ͒̚ġ̻͍̱̹̪̼̦ͩ̋̂ͮ̇̏̚͡o̲̎̏̈̉̿ͧ!̃̏̋ͨ͂̎ͭ͏̦̲̖̯͍̤
Same here (IE8). Crazyhorse’s post looks like a game of Missile Command.
All I see now is blonde, brunette, redhead.
Good metaphor.
I get vertical lines of diacritics in IE, and angled ones in FF and Chrome. There are differences in how stuff is displayed horizontally between browsers too. (Jragon’s thing also displays differently in IE to how it does in FF and Chrome.) Has anyone tried Safari or Opera? Apparently it happens under Android, as well as Windows 7 and 8 . Ha anyone tried on an Apple machine?
If I copy and paste to Notepad or Word, I just get a couple of diacritics above each character, not the long lines.
So is this a browser issue, or what? Is it the sort of bug that has the potential to be exploited by hackers?
As noted above, it’s not happening on Chrome on XP machines, and also not on Safari on an iPad, but it is happening across browsers on Win 7 and later(I guess nobody run Vista anymore, so there’s no feedback). It’s unlikely to be a browser issue.
There’s a Twitter account called Glitchr that makes heavy use of these characters to screw with people’s Twitter feeds.
They are Unicode characters called combining diacritical marks, and as others have said, they are supposed to go above and below the previous character in order to create composite characters that are not in the character set themselves.
Happening on Android Dolphin browser as well.
Yes.
I started composing a long post containing more than you’d ever want to know about Thai script and some computer implementations, but will instead just answer the question … 
Can I suggest that a moderator edit the original subject line so we don’t have this annoyance in the thread listings? And perhaps make it a fixed policy to do so?
Moderator Note
I removed the characters from the title since it gave the impression of some sort of rendering error to some and some others have found it annoying.
More tests, all Android:
Firefox - diagonal, same as Windows.
Dolphin - all looks normal with no corruption, except Jragon’s post #22.
Silk - diagonals, now with some verticals. Some diagonals are topped with verticals. Post #22 still looks weird, but it no longer spills out to the right and so the page is normal width.
Tapatalk - similar to Dolphin, not sure if that means more or less Unicode support.
Every time I view the page, I get a different effect. I went back up to the OP to taken another look at the X-shaped diagonals, and it was gone. I clidked on
[quote]
to see what the original looked like, and the X was within the quote box. When i back-arrowed out, and looked at the whole forum content, the big X was there, again, spreading out into the margins of my view, and all the way up through the forum display toolbar.
Vista, Firefox.
Editing – now, its gone again, except just above the two left odd characters. Bur when I refreshed, the whole X came back, covering the whole frame.
There is what thw quote field looks like
Re: the above. The effect sometimes goes away, just by scrolling up the screen and back down, then comes back again.
I copy/pasted the two Thai characters into Google Translate, and the following apeared in the blank space beneath the message box in Google Translate:
Kĥ̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂̂ T̩~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~̊̊̊̊̊̊̊̊̊̊̊̊
the ฏ๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎๎ํํํํํํํํํํํํ
This has to be a rendering error, right? Surely the actual Unicode specification would be to only display a fixed number of combing marks, depending on how many you actually used. There isn’t actually Unicode that indicates an varying number of marks, right? That would just be stupid.
But I’m having trouble of thinking of what possible legitimate specification would have this weirdness as a side effect.
I’d call it a rendering error, though it can be argued that display of ill-formed diacritical marks need not be defined. The rendering anomaly doesn’t appear in Notepad.
I may as well describe the symptom a bit.
The following (pronounced choo chii chii) means “The lover points to the nun.”
ชู้ชี้ชี
(I’ve used a large font so that this can be seen more clearly.) Note that the mai tho – the uppermost symbol which looks vaguely like a check mark – is elevated in the second word. It needs to be elevated because a vowel symbol is occupying its usual position. (Elevation is not necessary in the first word where the vowel appears under the consonant.)
Thus the context determines where the symbol (in this case, the mai tho tone mark) needs to be placed. Unicode has other combining symbols whose displayed location depends on context. An umlaut (Unicode decimal 776) is placed higher after a capital-U than after a small-u; however duplicated umlauts do not lead to false positionings in the Chrome browser. (And anyway, most European diacriticals are invoked via a single font element, rather than using combining characters.)
That answers your question; the remainder of this post is TL;DR.
Here is the Unicode which could be typed to produce that sentence, and definitions of its words. (I’ve left spaces after each # so that the Unicode doesn’t get interpreted.
&# 3594;&# 3637; – nun
&# 3594;&# 3637;&# 3657; – to indicate
&# 3594;&# 3641;&# 3657; – adulterous lover
&# 3594;&# 3637;&# 3657;&# 3657; (an impossible word with an illegal redundant tone mark)
&# 3594;&# 3641;&# 3594;&# 3637;&# 3657;&# 3594;&# 3637;&# 3594;&# 3637;&# 3657;&# 3657;
Here’s the same thing without the spaces after the #.
ชี[SIZE=“2”] – nun
ชี้ – to indicate
ชู้ – adulterous lover
ชี้้ (an impossible word with an illegal redundant tone mark)
ชู้ชี้ชีชี้้[/SIZE]
Computer implementations of Thai script 30+ years ago were quite clumsy. Some systems used four lines for one line of text: lines for (1) tone marks, (2) above vowels, (3) consonants and left-right vowels, (4) below vowels. With this system, a 24-line PC monitor could display only 6 lines of Thai text. An innovation was to provide a special font element for each combination of above-vowel and tone mark to get the Thai text to use only 3 lines. (Another way was to use the same line for tone marks as for the below-vowels of the preceding line, with a forced format change upon collision.) All these methods were quite clumsy. Thai typewriters had a similar problem, with tone marks appearing at a fixed location high enough to leave room for an above vowel. All of these systems were useless for quality documents: for one thing, when NOT required by an above vowel, it is unaesthetic to place the tone mark too high.
Thus, the implementation of Unicode combining characters is a huge improvement. The cascading of tone marks in words that are anyway illegal, may as well be considered a feature rather than bug!
Yeah, you can find out more by searching “stacked diacritics”. The funny thing is, FF knows about this, but refuses to fix it, saying it’s up to web pages to be well designed.