Re: [GENERAL] Surrogate pairs in UTF-8

2015-01-18 Thread Tom Lane
Martijn van Oosterhout klep...@svana.org writes:
 On Fri, Jan 16, 2015 at 08:16:47AM -0600, Dave Rosckes wrote:
 I have written a test program using postgres that creates a string with a
 surrogate pair.  I then insert that string into a varchar property in a
 table.
 
 I then execute a select statement to pull the string out.  But when I
 evaluate the string the lead char of the pair is correct, but the following
 pair value is mangled.  I run this exact same code using DB2 and it works
 just fine.
 
 Is this a postgres limitation, or is there a specific way surrogate pairs
 need to be handled?

 Sounds odd. Can you provide actual queries showing the problem (and
 server version).

Surrogate pairs are illegal in UTF-8, per its specification at
http://www.faqs.org/rfcs/rfc3629.html
You're supposed to encode the underlying code point, not a surrogate pair
(those are a UTF-16ism).  So if what you passed in was actually a
surrogate pair, it should have failed encoding validity check, or possibly
have gotten converted to the underlying single Unicode character depending
on exactly what code path is involved.

regards, tom lane


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Re: [GENERAL] Surrogate pairs in UTF-8

2015-01-18 Thread Martijn van Oosterhout
On Fri, Jan 16, 2015 at 08:16:47AM -0600, Dave Rosckes wrote:
 I have written a test program using postgres that creates a string with a
 surrogate pair.  I then insert that string into a varchar property in a
 table.
 
 I then execute a select statement to pull the string out.  But when I
 evaluate the string the lead char of the pair is correct, but the following
 pair value is mangled.  I run this exact same code using DB2 and it works
 just fine.
 
 Is this a postgres limitation, or is there a specific way surrogate pairs
 need to be handled?

Sounds odd. Can you provide actual queries showing the problem (and
server version).

Have a nice day,
-- 
Martijn van Oosterhout   klep...@svana.org   http://svana.org/kleptog/
 He who writes carelessly confesses thereby at the very outset that he does
 not attach much importance to his own thoughts.
   -- Arthur Schopenhauer


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