<!DOCTYPE html> <html> <head> <meta charset=utf-8> <title>Bug xxxx</title> <style> p { width:0; } .bmp { color: green; } .supp { color: blue; } </style> </head> <body> Line-breaking in the green (BMP) and blue (supplementary-plane) examples should match. <p class="bmp">abcdef ‘文’ abcdef</p> <p class="supp">abcdef ‘𠀋’ abcdef</p> </body> </html>