Merge branch 'js/range-diff-noprefix'

"git range-diff" segfaulted when diff.noprefix configuration was
used, as it blindly expected the patch it internally generates to
have the standard a/ and b/ prefixes.  The command now forces the
internal patch to be built without any prefix, not to be affected
by any end-user configuration.

* js/range-diff-noprefix:
  range-diff: internally force `diff.noprefix=true`

diff --cc t/t3206-range-diff.sh
Simple merge