Introduce vcs-svn lib

Teach the build system to build a separate library for the
upcoming subversion interop support.

The resulting vcs-svn/lib.a does not contain any code, nor is
it built during a normal build.  This is just scaffolding for
later changes.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NRamkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Makefile

@@ -468,6 +468,7 @@ export PYTHON_PATH
 
 LIB_FILE=libgit.a
 XDIFF_LIB=xdiff/lib.a
+VCSSVN_LIB=vcs-svn/lib.a
 
 LIB_H += advice.h
 LIB_H += archive.h
@@ -1739,7 +1740,8 @@ ifndef NO_CURL
 endif
 XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
-OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS)
+VCSSVN_OBJS =
+OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS) $(VCSSVN_OBJS)
 
 dep_files := $(foreach f,$(OBJECTS),$(dir $f).depend/$(notdir $f).d)
 dep_dirs := $(addsuffix .depend,$(sort $(dir $(OBJECTS))))
@@ -1861,6 +1863,8 @@ http.o http-walker.o http-push.o http-fetch.o remote-curl.o: http.h
 xdiff-interface.o $(XDIFF_OBJS): \
 	xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
 	xdiff/xutils.h xdiff/xprepare.h xdiff/xdiffi.h xdiff/xemit.h
+
+$(VCSSVN_OBJS):
 endif
 
 exec_cmd.s exec_cmd.o: EXTRA_CPPFLAGS = \
@@ -1909,6 +1913,8 @@ $(LIB_FILE): $(LIB_OBJS)
 $(XDIFF_LIB): $(XDIFF_OBJS)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(XDIFF_OBJS)
 
+$(VCSSVN_LIB): $(VCSSVN_OBJS)
+	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(VCSSVN_OBJS)
 
 doc:
 	$(MAKE) -C Documentation all

vcs-svn/LICENSE

+Copyright (C) 2010 David Barr <david.barr@cordelta.com>.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice(s), this list of conditions and the following disclaimer
+   unmodified other than the allowable addition of one or more
+   copyright notices.
+2. Redistributions in binary form must reproduce the above copyright
+   notice(s), this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.