FULL PRODUCT VERSION :
java version " 1.7.0_07 "
Java(TM) SE Runtime Environment (build 1.7.0_07-b10)
Java HotSpot(TM) 64-Bit Server VM (build 23.3-b01, mixed mode)
ADDITIONAL OS VERSION INFORMATION :
OS X 10.8.2
Darwin 12.2.0 Darwin Kernel Version 12.2.0: Sat Aug 25 00:48:52 PDT 2012; root:xnu-2050.18.24~1/RELEASE_X86_64 x86_64
A DESCRIPTION OF THE PROBLEM :
While testing using surrogate pairs we found a number of jvm bugs. This one is specific to OS X (works under Window 7) and possible Windows XP. It seems like it's not using the correct font to render glyphs for surrogate pairs. They either show up as boxes or as an incorrect glyph.
After patching BasicTextUI to fix pasting, usually they are boxes or incorrect glyphs, but when using the Character Viewer to enter in surrogates from CJK Unified Ideographs Ext. B (20000+) you see really odd behavior like it's interpreting each character as individual ascii char (I've seen things like it does a backspace, regular ascii chars, select all, delete).
STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
After fixing the bug in BasicTextUI related to importing (paste/drop) surrogate paris...
Try using the Character Viewer to enter in surrogate pairs (20000+) in JTextComponents (JTextField, JTextArea in particular, but all need to be validated).
EXPECTED VERSUS ACTUAL BEHAVIOR :
Characters should display like they do in Text Edit
Characters do not show up properly
This bug can be reproduced always.
CUSTOMER SUBMITTED WORKAROUND :
Use Windows 7 for testing. Most of our development staff is on OS X and it's frustrating to not be able to test surrogate pair issues on the mac due to glyph issues.