[Git] 'git svn dcommit' failed with big-size file.

When using 'git svn dcommit' (PortableGit-1.7.4-preview20110204.7z) to commit a large file, e.g. larger than 200MB, it shows some errors like:

Out of memory during "large" request for 268439552 bytes, total sbrk() is 141363200 bytes at /usr/lib/perl5/site_perl/Git.pm line 899, <GEN1> line 5.

by Googling, here is a patch and seems to work.