Description of problem:
Here are the steps:

1. I have fileA in both svn and my local git-svn repo
2. Make some changed to fileA
3. Create fileB, which is exact copy of the (modified) file A and git add it to the repo
4. commit both the (modified) fileA and the newly added (and identical) fileB, i.e., do a git commit on both
5. Try to push the commit to svn with "git svn dcommit"

git svn now complains similar to this:

Committing to blah ...
	C	fileA => fileB
perl: subversion/libsvn_subr/dirent_uri.c:2491: svn_fspath__skip_ancestor: Assertion `svn_fspath__is_canonical(child_fspath)' failed.
error: git-svn died of signal 6

Version-Release number of selected component:
git-svn-1.8.5.3-2.fc20

Additional info:
reporter:       libreport-2.1.12
backtrace_rating: 4
cmdline:        /usr/bin/perl /usr/libexec/git-core/git-svn dcommit
crash_function: svn_fspath__skip_ancestor
executable:     /usr/bin/perl
kernel:         3.12.9-301.fc20.x86_64
runlevel:       N 5
type:           CCpp
uid:            500

Truncated backtrace:
Thread no. 1 (10 frames)
 #4 svn_fspath__skip_ancestor at subversion/libsvn_subr/dirent_uri.c:2491
 #5 svn_ra_serf__get_relative_path at subversion/libsvn_ra_serf/util.c:2459
 #6 svn_ra_serf__get_stable_url at subversion/libsvn_ra_serf/property.c:1193
 #7 close_file at subversion/libsvn_ra_serf/commit.c:2100
 #8 svn_delta_editor_invoke_close_file at svn_delta.c:2047
 #9 _wrap_svn_delta_editor_invoke_close_file at svn_delta.c:7075
 #10 Perl_pp_entersub at pp_hot.c:2888
 #11 Perl_runops_standard at run.c:42
 #12 S_run_body at perl.c:2462
 #13 perl_run at perl.c:2383