"git format-patch" honors the src/dst prefixes set to nonstandard
values with configuration variables like "diff.noprefix", causing
receiving end of the patch that expects the standard -p1 format to
break. Teach "format-patch" to ignore end-user configuration and
always use the standard prefixes.
This is a backward compatibility breaking change.
* jk/format-patch-ignore-noprefix:
rebase: prefer --default-prefix to --{src,dst}-prefix for format-patch
format-patch: add format.noprefix option
format-patch: do not respect diff.noprefix
diff: add --default-prefix option
t4013: add tests for diff prefix options
diff: factor out src/dst prefix setup
15108de2fa