drop vcs-svn experiment

The code in vcs-svn was started in 2010 as an attempt to build a
remote-helper for interacting with svn repositories (as opposed to
git-svn). However, we never got as far as shipping a mature remote
helper, and the last substantive commit was e99d012a6bc in 2012.

We do have a git-remote-testsvn, and it is even installed as part of
"make install". But given the name, it seems unlikely to be used by
anybody (you'd have to explicitly "git clone testsvn::$url", and there
have been zero mentions of that on the mailing list since 2013, and even
that includes the phrase "you might need to hack a bit to get it working
properly"[1]).

We also ship contrib/svn-fe, which builds on the vcs-svn work. However,
it does not seem to build out of the box for me, as the link step misses
some required libraries for using libgit.a. Curiously, the original
build breakage bisects for me to eff80a9fd9 (Allow custom "comment
char", 2013-01-16), which seems unrelated. There was an attempt to fix
it in da011cb0e7 (contrib/svn-fe: fix Makefile, 2014-08-28), but on my
system that only switches the error message.

So it seems like the result is not really usable by anybody in practice.
It would be wonderful if somebody wanted to pick up the topic again, and
potentially it's worth carrying around for that reason. But the flip
side is that people doing tree-wide operations have to deal with this
code.  And you can see the list with (replace "HEAD" with this commit as
appropriate):

  {
    echo "--"
    git diff-tree --diff-filter=D -r --name-only HEAD^ HEAD
  } |
  git log --no-merges --oneline e99d012a6bc.. --stdin

which shows 58 times somebody had to deal with the code, generally due
to a compile or test failure, or a tree-wide style fix or API change.
Let's drop it and let anybody who wants to pick it up do so by
resurrecting it from the git history.

As a bonus, this also reduces the size of a stripped installation of Git
from 21MB to 19MB.

[1] https://lore.kernel.org/git/CALkWK0mPHzKfzFKKpZkfAus3YVC9NFYDbFnt+5JQYVKipk3bQQ@mail.gmail.com/

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

6 files changed, 5 insertions, 287 deletions

diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index 4a6f135b16..5007f173f1 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -502,7 +502,7 @@ unset(CMAKE_REQUIRED_INCLUDES)
 #programs
 set(PROGRAMS_BUILT
 	git git-daemon git-http-backend git-sh-i18n--envsubst
-	git-shell git-remote-testsvn)
+	git-shell)
 
 if(NOT CURL_FOUND)
 	list(APPEND excluded_progs git-http-fetch git-http-push)
@@ -568,12 +568,6 @@ parse_makefile_for_sources(libxdiff_SOURCES "XDIFF_OBJS")
 list(TRANSFORM libxdiff_SOURCES PREPEND "${CMAKE_SOURCE_DIR}/")
 add_library(xdiff STATIC ${libxdiff_SOURCES})
 
-#libvcs-svn
-parse_makefile_for_sources(libvcs-svn_SOURCES "VCSSVN_OBJS")
-
-list(TRANSFORM libvcs-svn_SOURCES PREPEND "${CMAKE_SOURCE_DIR}/")
-add_library(vcs-svn STATIC ${libvcs-svn_SOURCES})
-
 if(WIN32)
 	if(NOT MSVC)#use windres when compiling with gcc and clang
 		add_custom_command(OUTPUT ${CMAKE_BINARY_DIR}/git.res
@@ -654,9 +648,6 @@ if(CURL_FOUND)
 	endif()
 endif()
 
-add_executable(git-remote-testsvn ${CMAKE_SOURCE_DIR}/remote-testsvn.c)
-target_link_libraries(git-remote-testsvn common-main vcs-svn)
-
 set(git_builtin_extra
 	cherry cherry-pick format-patch fsck-objects
 	init merge-subtree restore show
@@ -832,12 +823,6 @@ if(BUILD_TESTING)
 add_executable(test-fake-ssh ${CMAKE_SOURCE_DIR}/t/helper/test-fake-ssh.c)
 target_link_libraries(test-fake-ssh common-main)
 
-add_executable(test-line-buffer ${CMAKE_SOURCE_DIR}/t/helper/test-line-buffer.c)
-target_link_libraries(test-line-buffer common-main vcs-svn)
-
-add_executable(test-svn-fe ${CMAKE_SOURCE_DIR}/t/helper/test-svn-fe.c)
-target_link_libraries(test-svn-fe common-main vcs-svn)
-
 #test-tool
 parse_makefile_for_sources(test-tool_SOURCES "TEST_BUILTINS_OBJS")
 
@@ -845,13 +830,13 @@ list(TRANSFORM test-tool_SOURCES PREPEND "${CMAKE_SOURCE_DIR}/t/helper/")
 add_executable(test-tool ${CMAKE_SOURCE_DIR}/t/helper/test-tool.c ${test-tool_SOURCES})
 target_link_libraries(test-tool common-main)
 
-set_target_properties(test-fake-ssh test-line-buffer test-svn-fe test-tool
+set_target_properties(test-fake-ssh test-tool
 			PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/t/helper)
 
 if(MSVC)
-	set_target_properties(test-fake-ssh test-line-buffer test-svn-fe test-tool
+	set_target_properties(test-fake-ssh test-tool
 				PROPERTIES RUNTIME_OUTPUT_DIRECTORY_DEBUG ${CMAKE_BINARY_DIR}/t/helper)
-	set_target_properties(test-fake-ssh test-line-buffer test-svn-fe test-tool
+	set_target_properties(test-fake-ssh test-tool
 				PROPERTIES RUNTIME_OUTPUT_DIRECTORY_RELEASE ${CMAKE_BINARY_DIR}/t/helper)
 endif()
 
@@ -860,7 +845,7 @@ set(wrapper_scripts
 	git git-upload-pack git-receive-pack git-upload-archive git-shell git-remote-ext)
 
 set(wrapper_test_scripts
-	test-fake-ssh test-line-buffer test-svn-fe test-tool)
+	test-fake-ssh test-tool)
 
 
 foreach(script ${wrapper_scripts})
@@ -961,7 +946,6 @@ if(NOT ${CMAKE_BINARY_DIR}/CMakeCache.txt STREQUAL ${CACHE_PATH})
 	file(COPY ${CMAKE_SOURCE_DIR}/mergetools/tkdiff DESTINATION ${CMAKE_BINARY_DIR}/mergetools/)
 	file(COPY ${CMAKE_SOURCE_DIR}/contrib/completion/git-prompt.sh DESTINATION ${CMAKE_BINARY_DIR}/contrib/completion/)
 	file(COPY ${CMAKE_SOURCE_DIR}/contrib/completion/git-completion.bash DESTINATION ${CMAKE_BINARY_DIR}/contrib/completion/)
-	file(COPY ${CMAKE_SOURCE_DIR}/contrib/svn-fe/svnrdump_sim.py DESTINATION ${CMAKE_BINARY_DIR}/contrib/svn-fe/)
 endif()
 
 file(GLOB test_scipts "${CMAKE_SOURCE_DIR}/t/t[0-9]*.sh")
diff --git a/contrib/svn-fe/.gitignore b/contrib/svn-fe/.gitignore
deleted file mode 100644
index 02a7791585..0000000000
--- a/contrib/svn-fe/.gitignore
+++ /dev/null
@@ -1,4 +0,0 @@
-/*.xml
-/*.1
-/*.html
-/svn-fe
diff --git a/contrib/svn-fe/Makefile b/contrib/svn-fe/Makefile
deleted file mode 100644
index e8651aaf4b..0000000000
--- a/contrib/svn-fe/Makefile
+++ /dev/null
@@ -1,105 +0,0 @@
-all:: svn-fe$X
-
-CC = cc
-RM = rm -f
-MV = mv
-
-CFLAGS = -g -O2 -Wall
-LDFLAGS =
-EXTLIBS = -lz
-
-include ../../config.mak.uname
--include ../../config.mak.autogen
--include ../../config.mak
-
-ifeq ($(uname_S),Darwin)
-	ifndef NO_FINK
-		ifeq ($(shell test -d /sw/lib && echo y),y)
-			CFLAGS += -I/sw/include
-			LDFLAGS += -L/sw/lib
-		endif
-	endif
-	ifndef NO_DARWIN_PORTS
-		ifeq ($(shell test -d /opt/local/lib && echo y),y)
-			CFLAGS += -I/opt/local/include
-			LDFLAGS += -L/opt/local/lib
-		endif
-	endif
-endif
-
-ifndef NO_OPENSSL
-	EXTLIBS += -lssl
-	ifdef NEEDS_CRYPTO_WITH_SSL
-		EXTLIBS += -lcrypto
-	endif
-endif
-
-ifndef NO_PTHREADS
-	CFLAGS += $(PTHREADS_CFLAGS)
-	EXTLIBS += $(PTHREAD_LIBS)
-endif
-
-ifdef HAVE_CLOCK_GETTIME
-	CFLAGS += -DHAVE_CLOCK_GETTIME
-	EXTLIBS += -lrt
-endif
-
-ifdef NEEDS_LIBICONV
-	EXTLIBS += -liconv
-endif
-
-GIT_LIB = ../../libgit.a
-VCSSVN_LIB = ../../vcs-svn/lib.a
-XDIFF_LIB = ../../xdiff/lib.a
-
-LIBS = $(VCSSVN_LIB) $(GIT_LIB) $(XDIFF_LIB)
-
-QUIET_SUBDIR0 = +$(MAKE) -C # space to separate -C and subdir
-QUIET_SUBDIR1 =
-
-ifneq ($(findstring $(MAKEFLAGS),w),w)
-PRINT_DIR = --no-print-directory
-else # "make -w"
-NO_SUBDIR = :
-endif
-
-ifneq ($(findstring $(MAKEFLAGS),s),s)
-ifndef V
-	QUIET_CC      = @echo '   ' CC $@;
-	QUIET_LINK    = @echo '   ' LINK $@;
-	QUIET_SUBDIR0 = +@subdir=
-	QUIET_SUBDIR1 = ;$(NO_SUBDIR) echo '   ' SUBDIR $$subdir; \
-	                $(MAKE) $(PRINT_DIR) -C $$subdir
-endif
-endif
-
-svn-fe$X: svn-fe.o $(VCSSVN_LIB) $(XDIFF_LIB) $(GIT_LIB)
-	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $(EXTLIBS) -o $@ svn-fe.o $(LIBS)
-
-svn-fe.o: svn-fe.c ../../vcs-svn/svndump.h
-	$(QUIET_CC)$(CC) $(CFLAGS) -I../../vcs-svn -o $*.o -c $<
-
-svn-fe.html: svn-fe.txt
-	$(QUIET_SUBDIR0)../../Documentation $(QUIET_SUBDIR1) \
-		MAN_TXT=../contrib/svn-fe/svn-fe.txt \
-		../contrib/svn-fe/$@
-
-svn-fe.1: svn-fe.txt
-	$(QUIET_SUBDIR0)../../Documentation $(QUIET_SUBDIR1) \
-		MAN_TXT=../contrib/svn-fe/svn-fe.txt \
-		../contrib/svn-fe/$@
-	$(MV) ../../Documentation/svn-fe.1 .
-
-../../vcs-svn/lib.a: FORCE
-	$(QUIET_SUBDIR0)../.. $(QUIET_SUBDIR1) vcs-svn/lib.a
-
-../../xdiff/lib.a: FORCE
-	$(QUIET_SUBDIR0)../.. $(QUIET_SUBDIR1) xdiff/lib.a
-
-../../libgit.a: FORCE
-	$(QUIET_SUBDIR0)../.. $(QUIET_SUBDIR1) libgit.a
-
-clean:
-	$(RM) svn-fe$X svn-fe.o svn-fe.html svn-fe.xml svn-fe.1
-
-.PHONY: all clean FORCE
diff --git a/contrib/svn-fe/svn-fe.c b/contrib/svn-fe/svn-fe.c
deleted file mode 100644
index f363505abb..0000000000
--- a/contrib/svn-fe/svn-fe.c
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * This file is in the public domain.
- * You may freely use, modify, distribute, and relicense it.
- */
-
-#include <stdlib.h>
-#include "svndump.h"
-
-int main(int argc, char **argv)
-{
-	if (svndump_init(NULL))
-		return 1;
-	svndump_read((argc > 1) ? argv[1] : NULL, "refs/heads/master",
-			"refs/notes/svn/revs");
-	svndump_deinit();
-	svndump_reset();
-	return 0;
-}
diff --git a/contrib/svn-fe/svn-fe.txt b/contrib/svn-fe/svn-fe.txt
deleted file mode 100644
index 19333fc8df..0000000000
--- a/contrib/svn-fe/svn-fe.txt
+++ /dev/null
@@ -1,71 +0,0 @@
-svn-fe(1)
-=========
-
-NAME
-----
-svn-fe - convert an SVN "dumpfile" to a fast-import stream
-
-SYNOPSIS
---------
-[verse]
-mkfifo backchannel &&
-svnadmin dump --deltas REPO |
-	svn-fe [url] 3<backchannel |
-	git fast-import --cat-blob-fd=3 3>backchannel
-
-DESCRIPTION
------------
-
-Converts a Subversion dumpfile into input suitable for
-git-fast-import(1) and similar importers. REPO is a path to a
-Subversion repository mirrored on the local disk. Remote Subversion
-repositories can be mirrored on local disk using the `svnsync`
-command.
-
-Note: this tool is very young.  The details of its commandline
-interface may change in backward incompatible ways.
-
-INPUT FORMAT
-------------
-Subversion's repository dump format is documented in full in
-`notes/dump-load-format.txt` from the Subversion source tree.
-Files in this format can be generated using the 'svnadmin dump' or
-'svk admin dump' command.
-
-OUTPUT FORMAT
--------------
-The fast-import format is documented by the git-fast-import(1)
-manual page.
-
-NOTES
------
-Subversion dumps do not record a separate author and committer for
-each revision, nor do they record a separate display name and email
-address for each author.  Like git-svn(1), 'svn-fe' will use the name
-
----------
-user <user@UUID>
----------
-
-as committer, where 'user' is the value of the `svn:author` property
-and 'UUID' the repository's identifier.
-
-To support incremental imports, 'svn-fe' puts a `git-svn-id` line at
-the end of each commit log message if passed a URL on the command
-line.  This line has the form `git-svn-id: URL@REVNO UUID`.
-
-The resulting repository will generally require further processing
-to put each project in its own repository and to separate the history
-of each branch.  The 'git filter-repo --subdirectory-filter' command
-may be useful for this purpose.
-
-BUGS
-----
-Empty directories and unknown properties are silently discarded.
-
-The exit status does not reflect whether an error was detected.
-
-SEE ALSO
---------
-git-svn(1), svn2git(1), svk(1), git-filter-repo(1), git-fast-import(1),
-https://svn.apache.org/repos/asf/subversion/trunk/notes/dump-load-format.txt
diff --git a/contrib/svn-fe/svnrdump_sim.py b/contrib/svn-fe/svnrdump_sim.py
deleted file mode 100755
index 8a3cee6175..0000000000
--- a/contrib/svn-fe/svnrdump_sim.py
+++ /dev/null
@@ -1,68 +0,0 @@
-#!/usr/bin/env python
-"""
-Simulates svnrdump by replaying an existing dump from a file, taking care
-of the specified revision range.
-To simulate incremental imports the environment variable SVNRMAX can be set
-to the highest revision that should be available.
-"""
-import sys
-import os
-
-if sys.hexversion < 0x02040000:
-    # The limiter is the ValueError() calls. This may be too conservative
-    sys.stderr.write("svnrdump-sim.py: requires Python 2.4 or later.\n")
-    sys.exit(1)
-
-
-def getrevlimit():
-    var = 'SVNRMAX'
-    if var in os.environ:
-        return os.environ[var]
-    return None
-
-
-def writedump(url, lower, upper):
-    if url.startswith('sim://'):
-        filename = url[6:]
-        if filename[-1] == '/':
-            filename = filename[:-1]  # remove terminating slash
-    else:
-        raise ValueError('sim:// url required')
-    f = open(filename, 'r')
-    state = 'header'
-    wroterev = False
-    while(True):
-        l = f.readline()
-        if l == '':
-            break
-        if state == 'header' and l.startswith('Revision-number: '):
-            state = 'prefix'
-        if state == 'prefix' and l == 'Revision-number: %s\n' % lower:
-            state = 'selection'
-        if not upper == 'HEAD' and state == 'selection' and \
-                l == 'Revision-number: %s\n' % upper:
-            break
-
-        if state == 'header' or state == 'selection':
-            if state == 'selection':
-                wroterev = True
-            sys.stdout.write(l)
-    return wroterev
-
-if __name__ == "__main__":
-    if not (len(sys.argv) in (3, 4, 5)):
-        print("usage: %s dump URL -rLOWER:UPPER")
-        sys.exit(1)
-    if not sys.argv[1] == 'dump':
-        raise NotImplementedError('only "dump" is supported.')
-    url = sys.argv[2]
-    r = ('0', 'HEAD')
-    if len(sys.argv) == 4 and sys.argv[3][0:2] == '-r':
-        r = sys.argv[3][2:].lstrip().split(':')
-    if not getrevlimit() is None:
-        r[1] = getrevlimit()
-    if writedump(url, r[0], r[1]):
-        ret = 0
-    else:
-        ret = 1
-    sys.exit(ret)