[THRIFT-2870] C++ TJSONProtocol using locale dependent formatting

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9
• Fix Version/s: 0.9.3
• Component/s: C++ - Library

Environment

Linux, Boost 1.51

• Assignee: Konrad Grochowski
• Reporter: Simon Falsig
• Created: 02/Dec/14 14:58
• Updated: 21/Jul/15 02:21
• Resolved: 23/Feb/15 17:24

Description

I'm using Thrift for serializing objects (in C++) into JSON strings, which I then store as files. This usually works fine, but if the locale of my system is set to a locale where the decimal separator is ',' instead of '.' (for instance in Denmark), then the TJSONProtocol (specifically the writeJSONDouble function that does the double to string conversion through a boost::lexical_cast) will also use this separator when serializing doubles.

This kinda plays havoc with the JSON specification, which does not allow for localized formatting, and depends on always using '.' as a decimal separator. I could imagine that there may be other more subtle places where the local can have an effect, but this is currently the only place I've been having trouble with.

I can see that the same problem has been fixed for C# (commit
3da317bda100130b2f615034c46b0944888f0f14 / THRIFT-1245 C# JSON Protocol uses culture-dependant decimal separator for double) but it doesn't seem as if there's a similarly easy way to fix boost::lexical_cast...

Note that I'm using Thrift 0.9.0, but as far as I can see there hasn't been any relevant changes to TJSONProtocol.cpp since.

Relevant thread on thrift-user mailing list can be found here: http://mail-archives.apache.org/mod_mbox/thrift-user/201412.mbox/[e-mail]%3e

I've also attached a quick patch that works on my setup (see the patch file comments for more information).