Adding upstream version 1:2.43.0.upstream/1%2.43.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

10 files changed, 3589 insertions, 0 deletions

diff --git a/contrib/subtree/.gitignore b/contrib/subtree/.gitignore
new file mode 100644
index 0000000..0b9381a
--- /dev/null
+++ b/contrib/subtree/.gitignore
@@ -0,0 +1,7 @@
+*~
+git-subtree
+git-subtree.1
+git-subtree.html
+git-subtree.xml
+mainline
+subproj
diff --git a/contrib/subtree/COPYING b/contrib/subtree/COPYING
new file mode 100644
index 0000000..d511905
--- /dev/null
+++ b/contrib/subtree/COPYING
@@ -0,0 +1,339 @@
+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+			    Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+		    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
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+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
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+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
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+distribute the same sections as part of a whole which is a work based
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+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
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+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
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+  6. Each time you redistribute the Program (or any work based on the
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+
+This section is intended to make thoroughly clear what is believed to
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+
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+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
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+
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+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
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+			    NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
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+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+		     END OF TERMS AND CONDITIONS
+
+	    How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) year name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.
diff --git a/contrib/subtree/INSTALL b/contrib/subtree/INSTALL
new file mode 100644
index 0000000..7ab0cf4
--- /dev/null
+++ b/contrib/subtree/INSTALL
@@ -0,0 +1,28 @@
+HOW TO INSTALL git-subtree
+==========================
+
+First, build from the top source directory.
+
+Then, in contrib/subtree, run:
+
+  make
+  make install
+  make install-doc
+
+If you used configure to do the main build the git-subtree build will
+pick up those settings.  If not, you will likely have to provide a
+value for prefix:
+
+  make prefix=<some dir>
+  make prefix=<some dir> install
+  make prefix=<some dir> install-doc
+
+To run tests first copy git-subtree to the main build area so the
+newly-built git can find it:
+
+  cp git-subtree ../..
+
+Then:
+
+  make test
+
diff --git a/contrib/subtree/Makefile b/contrib/subtree/Makefile
new file mode 100644
index 0000000..6fa7496
--- /dev/null
+++ b/contrib/subtree/Makefile
@@ -0,0 +1,103 @@
+# The default target of this Makefile is...
+all::
+
+-include ../../config.mak.autogen
+-include ../../config.mak
+
+prefix ?= /usr/local
+gitexecdir ?= $(prefix)/libexec/git-core
+mandir ?= $(prefix)/share/man
+man1dir ?= $(mandir)/man1
+htmldir ?= $(prefix)/share/doc/git-doc
+
+../../GIT-VERSION-FILE: FORCE
+	$(MAKE) -C ../../ GIT-VERSION-FILE
+
+-include ../../GIT-VERSION-FILE
+
+# this should be set to a 'standard' bsd-type install program
+INSTALL  ?= install
+RM       ?= rm -f
+
+ASCIIDOC         = asciidoc
+ASCIIDOC_CONF    = -f ../../Documentation/asciidoc.conf
+ASCIIDOC_HTML    = xhtml11
+ASCIIDOC_DOCBOOK = docbook
+ASCIIDOC_EXTRA   =
+XMLTO            = xmlto
+XMLTO_EXTRA      =
+
+ifdef USE_ASCIIDOCTOR
+ASCIIDOC         = asciidoctor
+ASCIIDOC_CONF    =
+ASCIIDOC_HTML    = xhtml5
+ASCIIDOC_DOCBOOK = docbook
+ASCIIDOC_EXTRA  += -I../../Documentation -rasciidoctor-extensions
+ASCIIDOC_EXTRA  += -alitdd='&\#x2d;&\#x2d;'
+XMLTO_EXTRA     += --skip-validation
+endif
+
+ifndef SHELL_PATH
+	SHELL_PATH = /bin/sh
+endif
+SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
+
+MANPAGE_XSL   = ../../Documentation/manpage-normal.xsl
+
+GIT_SUBTREE_SH := git-subtree.sh
+GIT_SUBTREE    := git-subtree
+
+GIT_SUBTREE_DOC := git-subtree.1
+GIT_SUBTREE_XML := git-subtree.xml
+GIT_SUBTREE_TXT := git-subtree.txt
+GIT_SUBTREE_HTML := git-subtree.html
+GIT_SUBTREE_TEST := ../../git-subtree
+
+all:: $(GIT_SUBTREE)
+
+$(GIT_SUBTREE): $(GIT_SUBTREE_SH)
+	sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' $< >$@
+	chmod +x $@
+
+doc: $(GIT_SUBTREE_DOC) $(GIT_SUBTREE_HTML)
+
+man: $(GIT_SUBTREE_DOC)
+
+html: $(GIT_SUBTREE_HTML)
+
+install: $(GIT_SUBTREE)
+	$(INSTALL) -d -m 755 $(DESTDIR)$(gitexecdir)
+	$(INSTALL) -m 755 $(GIT_SUBTREE) $(DESTDIR)$(gitexecdir)
+
+install-doc: install-man install-html
+
+install-man: $(GIT_SUBTREE_DOC)
+	$(INSTALL) -d -m 755 $(DESTDIR)$(man1dir)
+	$(INSTALL) -m 644 $^ $(DESTDIR)$(man1dir)
+
+install-html: $(GIT_SUBTREE_HTML)
+	$(INSTALL) -d -m 755 $(DESTDIR)$(htmldir)
+	$(INSTALL) -m 644 $^ $(DESTDIR)$(htmldir)
+
+$(GIT_SUBTREE_DOC): $(GIT_SUBTREE_XML)
+	$(XMLTO) -m $(MANPAGE_XSL) $(XMLTO_EXTRA) man $^
+
+$(GIT_SUBTREE_XML): $(GIT_SUBTREE_TXT)
+	$(ASCIIDOC) -b $(ASCIIDOC_DOCBOOK) -d manpage $(ASCIIDOC_CONF) \
+		-agit_version=$(GIT_VERSION) $(ASCIIDOC_EXTRA) $^
+
+$(GIT_SUBTREE_HTML): $(GIT_SUBTREE_TXT)
+	$(ASCIIDOC) -b $(ASCIIDOC_HTML) -d manpage $(ASCIIDOC_CONF) \
+		-agit_version=$(GIT_VERSION) $(ASCIIDOC_EXTRA) $^
+
+$(GIT_SUBTREE_TEST): $(GIT_SUBTREE)
+	cp $< $@
+
+test: $(GIT_SUBTREE_TEST)
+	$(MAKE) -C t/ test
+
+clean:
+	$(RM) $(GIT_SUBTREE)
+	$(RM) *.xml *.html *.1
+
+.PHONY: FORCE
diff --git a/contrib/subtree/README b/contrib/subtree/README
new file mode 100644
index 0000000..c686b4a
--- /dev/null
+++ b/contrib/subtree/README
@@ -0,0 +1,8 @@
+
+Please read git-subtree.txt for documentation.
+
+Please don't contact me using github mail; it's slow, ugly, and worst of
+all, redundant. Email me instead at apenwarr@gmail.com and I'll be happy to
+help.
+
+Avery
diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
new file mode 100755
index 0000000..e0c5d3b
--- /dev/null
+++ b/contrib/subtree/git-subtree.sh
@@ -0,0 +1,1092 @@
+#!/bin/sh
+#
+# git-subtree.sh: split/join git repositories in subdirectories of this one
+#
+# Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>
+#
+
+if test -z "$GIT_EXEC_PATH" || ! test -f "$GIT_EXEC_PATH/git-sh-setup" || {
+	test "${PATH#"${GIT_EXEC_PATH}:"}" = "$PATH" &&
+	test ! "$GIT_EXEC_PATH" -ef "${PATH%%:*}" 2>/dev/null
+}
+then
+	basename=${0##*[/\\]}
+	echo >&2 'It looks like either your git installation or your'
+	echo >&2 'git-subtree installation is broken.'
+	echo >&2
+	echo >&2 "Tips:"
+	echo >&2 " - If \`git --exec-path\` does not print the correct path to"
+	echo >&2 "   your git install directory, then set the GIT_EXEC_PATH"
+	echo >&2 "   environment variable to the correct directory."
+	echo >&2 " - Make sure that your \`$basename\` file is either in your"
+	echo >&2 "   PATH or in your git exec path (\`$(git --exec-path)\`)."
+	echo >&2 " - You should run git-subtree as \`git ${basename#git-}\`,"
+	echo >&2 "   not as \`$basename\`." >&2
+	exit 126
+fi
+
+OPTS_SPEC="\
+git subtree add   --prefix=<prefix> <commit>
+git subtree add   --prefix=<prefix> <repository> <ref>
+git subtree merge --prefix=<prefix> <commit>
+git subtree split --prefix=<prefix> [<commit>]
+git subtree pull  --prefix=<prefix> <repository> <ref>
+git subtree push  --prefix=<prefix> <repository> <refspec>
+--
+h,help!       show the help
+q,quiet!      quiet
+d,debug!      show debug messages
+P,prefix=     the name of the subdir to split out
+ options for 'split' (also: 'push')
+annotate=     add a prefix to commit message of new commits
+b,branch!=    create a new branch from the split subtree
+ignore-joins  ignore prior --rejoin commits
+onto=         try connecting new tree to an existing one
+rejoin        merge the new branch back into HEAD
+ options for 'add' and 'merge' (also: 'pull', 'split --rejoin', and 'push --rejoin')
+squash        merge subtree changes as a single commit
+m,message!=   use the given message as the commit message for the merge commit
+"
+
+indent=0
+
+# Usage: say [MSG...]
+say () {
+	if test -z "$arg_quiet"
+	then
+		printf '%s\n' "$*"
+	fi
+}
+
+# Usage: debug [MSG...]
+debug () {
+	if test -n "$arg_debug"
+	then
+		printf "%$(($indent * 2))s%s\n" '' "$*" >&2
+	fi
+}
+
+# Usage: progress [MSG...]
+progress () {
+	if test -z "$arg_quiet"
+	then
+		if test -z "$arg_debug"
+		then
+			# Debug mode is off.
+			#
+			# Print one progress line that we keep updating (use
+			# "\r" to return to the beginning of the line, rather
+			# than "\n" to start a new line).  This only really
+			# works when stderr is a terminal.
+			printf "%s\r" "$*" >&2
+		else
+			# Debug mode is on.  The `debug` function is regularly
+			# printing to stderr.
+			#
+			# Don't do the one-line-with-"\r" thing, because on a
+			# terminal the debug output would overwrite and hide the
+			# progress output.  Add a "progress:" prefix to make the
+			# progress output and the debug output easy to
+			# distinguish.  This ensures maximum readability whether
+			# stderr is a terminal or a file.
+			printf "progress: %s\n" "$*" >&2
+		fi
+	fi
+}
+
+# Usage: assert CMD...
+assert () {
+	if ! "$@"
+	then
+		die "fatal: assertion failed: $*"
+	fi
+}
+
+# Usage: die_incompatible_opt OPTION COMMAND
+die_incompatible_opt () {
+	assert test "$#" = 2
+	opt="$1"
+	arg_command="$2"
+	die "fatal: the '$opt' flag does not make sense with 'git subtree $arg_command'."
+}
+
+main () {
+	if test $# -eq 0
+	then
+		set -- -h
+	fi
+	set_args="$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
+	eval "$set_args"
+	. git-sh-setup
+	require_work_tree
+
+	# First figure out the command and whether we use --rejoin, so
+	# that we can provide more helpful validation when we do the
+	# "real" flag parsing.
+	arg_split_rejoin=
+	allow_split=
+	allow_addmerge=
+	while test $# -gt 0
+	do
+		opt="$1"
+		shift
+		case "$opt" in
+			--annotate|-b|-P|-m|--onto)
+				shift
+				;;
+			--rejoin)
+				arg_split_rejoin=1
+				;;
+			--no-rejoin)
+				arg_split_rejoin=
+				;;
+			--)
+				break
+				;;
+		esac
+	done
+	arg_command=$1
+	case "$arg_command" in
+	add|merge|pull)
+		allow_addmerge=1
+		;;
+	split|push)
+		allow_split=1
+		allow_addmerge=$arg_split_rejoin
+		;;
+	*)
+		die "fatal: unknown command '$arg_command'"
+		;;
+	esac
+	# Reset the arguments array for "real" flag parsing.
+	eval "$set_args"
+
+	# Begin "real" flag parsing.
+	arg_quiet=
+	arg_debug=
+	arg_prefix=
+	arg_split_branch=
+	arg_split_onto=
+	arg_split_ignore_joins=
+	arg_split_annotate=
+	arg_addmerge_squash=
+	arg_addmerge_message=
+	while test $# -gt 0
+	do
+		opt="$1"
+		shift
+
+		case "$opt" in
+		-q)
+			arg_quiet=1
+			;;
+		-d)
+			arg_debug=1
+			;;
+		--annotate)
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
+			arg_split_annotate="$1"
+			shift
+			;;
+		--no-annotate)
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
+			arg_split_annotate=
+			;;
+		-b)
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
+			arg_split_branch="$1"
+			shift
+			;;
+		-P)
+			arg_prefix="${1%/}"
+			shift
+			;;
+		-m)
+			test -n "$allow_addmerge" || die_incompatible_opt "$opt" "$arg_command"
+			arg_addmerge_message="$1"
+			shift
+			;;
+		--no-prefix)
+			arg_prefix=
+			;;
+		--onto)
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
+			arg_split_onto="$1"
+			shift
+			;;
+		--no-onto)
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
+			arg_split_onto=
+			;;
+		--rejoin)
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
+			;;
+		--no-rejoin)
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
+			;;
+		--ignore-joins)
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
+			arg_split_ignore_joins=1
+			;;
+		--no-ignore-joins)
+			test -n "$allow_split" || die_incompatible_opt "$opt" "$arg_command"
+			arg_split_ignore_joins=
+			;;
+		--squash)
+			test -n "$allow_addmerge" || die_incompatible_opt "$opt" "$arg_command"
+			arg_addmerge_squash=1
+			;;
+		--no-squash)
+			test -n "$allow_addmerge" || die_incompatible_opt "$opt" "$arg_command"
+			arg_addmerge_squash=
+			;;
+		--)
+			break
+			;;
+		*)
+			die "fatal: unexpected option: $opt"
+			;;
+		esac
+	done
+	shift
+
+	if test -z "$arg_prefix"
+	then
+		die "fatal: you must provide the --prefix option."
+	fi
+
+	case "$arg_command" in
+	add)
+		test -e "$arg_prefix" &&
+			die "fatal: prefix '$arg_prefix' already exists."
+		;;
+	*)
+		test -e "$arg_prefix" ||
+			die "fatal: '$arg_prefix' does not exist; use 'git subtree add'"
+		;;
+	esac
+
+	dir="$(dirname "$arg_prefix/.")"
+
+	debug "command: {$arg_command}"
+	debug "quiet: {$arg_quiet}"
+	debug "dir: {$dir}"
+	debug "opts: {$*}"
+	debug
+
+	"cmd_$arg_command" "$@"
+}
+
+# Usage: cache_setup
+cache_setup () {
+	assert test $# = 0
+	cachedir="$GIT_DIR/subtree-cache/$$"
+	rm -rf "$cachedir" ||
+		die "fatal: can't delete old cachedir: $cachedir"
+	mkdir -p "$cachedir" ||
+		die "fatal: can't create new cachedir: $cachedir"
+	mkdir -p "$cachedir/notree" ||
+		die "fatal: can't create new cachedir: $cachedir/notree"
+	debug "Using cachedir: $cachedir" >&2
+}
+
+# Usage: cache_get [REVS...]
+cache_get () {
+	for oldrev in "$@"
+	do
+		if test -r "$cachedir/$oldrev"
+		then
+			read newrev <"$cachedir/$oldrev"
+			echo $newrev
+		fi
+	done
+}
+
+# Usage: cache_miss [REVS...]
+cache_miss () {
+	for oldrev in "$@"
+	do
+		if ! test -r "$cachedir/$oldrev"
+		then
+			echo $oldrev
+		fi
+	done
+}
+
+# Usage: check_parents [REVS...]
+check_parents () {
+	missed=$(cache_miss "$@") || exit $?
+	local indent=$(($indent + 1))
+	for miss in $missed
+	do
+		if ! test -r "$cachedir/notree/$miss"
+		then
+			debug "incorrect order: $miss"
+			process_split_commit "$miss" ""
+		fi
+	done
+}
+
+# Usage: set_notree REV
+set_notree () {
+	assert test $# = 1
+	echo "1" > "$cachedir/notree/$1"
+}
+
+# Usage: cache_set OLDREV NEWREV
+cache_set () {
+	assert test $# = 2
+	oldrev="$1"
+	newrev="$2"
+	if test "$oldrev" != "latest_old" &&
+		test "$oldrev" != "latest_new" &&
+		test -e "$cachedir/$oldrev"
+	then
+		die "fatal: cache for $oldrev already exists!"
+	fi
+	echo "$newrev" >"$cachedir/$oldrev"
+}
+
+# Usage: rev_exists REV
+rev_exists () {
+	assert test $# = 1
+	if git rev-parse "$1" >/dev/null 2>&1
+	then
+		return 0
+	else
+		return 1
+	fi
+}
+
+# Usage: try_remove_previous REV
+#
+# If a commit doesn't have a parent, this might not work.  But we only want
+# to remove the parent from the rev-list, and since it doesn't exist, it won't
+# be there anyway, so do nothing in that case.
+try_remove_previous () {
+	assert test $# = 1
+	if rev_exists "$1^"
+	then
+		echo "^$1^"
+	fi
+}
+
+# Usage: process_subtree_split_trailer SPLIT_HASH MAIN_HASH [REPOSITORY]
+process_subtree_split_trailer () {
+	assert test $# = 2 -o $# = 3
+	b="$1"
+	sq="$2"
+	repository=""
+	if test "$#" = 3
+	then
+		repository="$3"
+	fi
+	fail_msg="fatal: could not rev-parse split hash $b from commit $sq"
+	if ! sub="$(git rev-parse --verify --quiet "$b^{commit}")"
+	then
+		# if 'repository' was given, try to fetch the 'git-subtree-split' hash
+		# before 'rev-parse'-ing it again, as it might be a tag that we do not have locally
+		if test -n "${repository}"
+		then
+			git fetch "$repository" "$b"
+			sub="$(git rev-parse --verify --quiet "$b^{commit}")" ||
+				die "$fail_msg"
+		else
+			hint1=$(printf "hint: hash might be a tag, try fetching it from the subtree repository:")
+			hint2=$(printf "hint:    git fetch <subtree-repository> $b")
+			fail_msg=$(printf "$fail_msg\n$hint1\n$hint2")
+			die "$fail_msg"
+		fi
+	fi
+}
+
+# Usage: find_latest_squash DIR [REPOSITORY]
+find_latest_squash () {
+	assert test $# = 1 -o $# = 2
+	dir="$1"
+	repository=""
+	if test "$#" = 2
+	then
+		repository="$2"
+	fi
+	debug "Looking for latest squash (dir=$dir, repository=$repository)..."
+	local indent=$(($indent + 1))
+
+	sq=
+	main=
+	sub=
+	git log --grep="^git-subtree-dir: $dir/*\$" \
+		--no-show-signature --pretty=format:'START %H%n%s%n%n%b%nEND%n' HEAD |
+	while read a b junk
+	do
+		debug "$a $b $junk"
+		debug "{{$sq/$main/$sub}}"
+		case "$a" in
+		START)
+			sq="$b"
+			;;
+		git-subtree-mainline:)
+			main="$b"
+			;;
+		git-subtree-split:)
+			process_subtree_split_trailer "$b" "$sq" "$repository"
+			;;
+		END)
+			if test -n "$sub"
+			then
+				if test -n "$main"
+				then
+					# a rejoin commit?
+					# Pretend its sub was a squash.
+					sq=$(git rev-parse --verify "$sq^2") ||
+						die
+				fi
+				debug "Squash found: $sq $sub"
+				echo "$sq" "$sub"
+				break
+			fi
+			sq=
+			main=
+			sub=
+			;;
+		esac
+	done || exit $?
+}
+
+# Usage: find_existing_splits DIR REV [REPOSITORY]
+find_existing_splits () {
+	assert test $# = 2 -o $# = 3
+	debug "Looking for prior splits..."
+	local indent=$(($indent + 1))
+
+	dir="$1"
+	rev="$2"
+	repository=""
+	if test "$#" = 3
+	then
+		repository="$3"
+	fi
+	main=
+	sub=
+	local grep_format="^git-subtree-dir: $dir/*\$"
+	if test -n "$arg_split_ignore_joins"
+	then
+		grep_format="^Add '$dir/' from commit '"
+	fi
+	git log --grep="$grep_format" \
+		--no-show-signature --pretty=format:'START %H%n%s%n%n%b%nEND%n' "$rev" |
+	while read a b junk
+	do
+		case "$a" in
+		START)
+			sq="$b"
+			;;
+		git-subtree-mainline:)
+			main="$b"
+			;;
+		git-subtree-split:)
+			process_subtree_split_trailer "$b" "$sq" "$repository"
+			;;
+		END)
+			debug "Main is: '$main'"
+			if test -z "$main" -a -n "$sub"
+			then
+				# squash commits refer to a subtree
+				debug "  Squash: $sq from $sub"
+				cache_set "$sq" "$sub"
+			fi
+			if test -n "$main" -a -n "$sub"
+			then
+				debug "  Prior: $main -> $sub"
+				cache_set $main $sub
+				cache_set $sub $sub
+				try_remove_previous "$main"
+				try_remove_previous "$sub"
+			fi
+			main=
+			sub=
+			;;
+		esac
+	done || exit $?
+}
+
+# Usage: copy_commit REV TREE FLAGS_STR
+copy_commit () {
+	assert test $# = 3
+	# We're going to set some environment vars here, so
+	# do it in a subshell to get rid of them safely later
+	debug copy_commit "{$1}" "{$2}" "{$3}"
+	git log -1 --no-show-signature --pretty=format:'%an%n%ae%n%aD%n%cn%n%ce%n%cD%n%B' "$1" |
+	(
+		read GIT_AUTHOR_NAME
+		read GIT_AUTHOR_EMAIL
+		read GIT_AUTHOR_DATE
+		read GIT_COMMITTER_NAME
+		read GIT_COMMITTER_EMAIL
+		read GIT_COMMITTER_DATE
+		export  GIT_AUTHOR_NAME \
+			GIT_AUTHOR_EMAIL \
+			GIT_AUTHOR_DATE \
+			GIT_COMMITTER_NAME \
+			GIT_COMMITTER_EMAIL \
+			GIT_COMMITTER_DATE
+		(
+			printf "%s" "$arg_split_annotate"
+			cat
+		) |
+		git commit-tree "$2" $3  # reads the rest of stdin
+	) || die "fatal: can't copy commit $1"
+}
+
+# Usage: add_msg DIR LATEST_OLD LATEST_NEW
+add_msg () {
+	assert test $# = 3
+	dir="$1"
+	latest_old="$2"
+	latest_new="$3"
+	if test -n "$arg_addmerge_message"
+	then
+		commit_message="$arg_addmerge_message"
+	else
+		commit_message="Add '$dir/' from commit '$latest_new'"
+	fi
+	if test -n "$arg_split_rejoin"
+	then
+		# If this is from a --rejoin, then rejoin_msg has
+		# already inserted the `git-subtree-xxx:` tags
+		echo "$commit_message"
+		return
+	fi
+	cat <<-EOF
+		$commit_message
+
+		git-subtree-dir: $dir
+		git-subtree-mainline: $latest_old
+		git-subtree-split: $latest_new
+	EOF
+}
+
+# Usage: add_squashed_msg REV DIR
+add_squashed_msg () {
+	assert test $# = 2
+	if test -n "$arg_addmerge_message"
+	then
+		echo "$arg_addmerge_message"
+	else
+		echo "Merge commit '$1' as '$2'"
+	fi
+}
+
+# Usage: rejoin_msg DIR LATEST_OLD LATEST_NEW
+rejoin_msg () {
+	assert test $# = 3
+	dir="$1"
+	latest_old="$2"
+	latest_new="$3"
+	if test -n "$arg_addmerge_message"
+	then
+		commit_message="$arg_addmerge_message"
+	else
+		commit_message="Split '$dir/' into commit '$latest_new'"
+	fi
+	cat <<-EOF
+		$commit_message
+
+		git-subtree-dir: $dir
+		git-subtree-mainline: $latest_old
+		git-subtree-split: $latest_new
+	EOF
+}
+
+# Usage: squash_msg DIR OLD_SUBTREE_COMMIT NEW_SUBTREE_COMMIT
+squash_msg () {
+	assert test $# = 3
+	dir="$1"
+	oldsub="$2"
+	newsub="$3"
+	newsub_short=$(git rev-parse --short "$newsub")
+
+	if test -n "$oldsub"
+	then
+		oldsub_short=$(git rev-parse --short "$oldsub")
+		echo "Squashed '$dir/' changes from $oldsub_short..$newsub_short"
+		echo
+		git log --no-show-signature --pretty=tformat:'%h %s' "$oldsub..$newsub"
+		git log --no-show-signature --pretty=tformat:'REVERT: %h %s' "$newsub..$oldsub"
+	else
+		echo "Squashed '$dir/' content from commit $newsub_short"
+	fi
+
+	echo
+	echo "git-subtree-dir: $dir"
+	echo "git-subtree-split: $newsub"
+}
+
+# Usage: toptree_for_commit COMMIT
+toptree_for_commit () {
+	assert test $# = 1
+	commit="$1"
+	git rev-parse --verify "$commit^{tree}" || exit $?
+}
+
+# Usage: subtree_for_commit COMMIT DIR
+subtree_for_commit () {
+	assert test $# = 2
+	commit="$1"
+	dir="$2"
+	git ls-tree "$commit" -- "$dir" |
+	while read mode type tree name
+	do
+		assert test "$name" = "$dir"
+		assert test "$type" = "tree" -o "$type" = "commit"
+		test "$type" = "commit" && continue  # ignore submodules
+		echo $tree
+		break
+	done || exit $?
+}
+
+# Usage: tree_changed TREE [PARENTS...]
+tree_changed () {
+	assert test $# -gt 0
+	tree=$1
+	shift
+	if test $# -ne 1
+	then
+		return 0   # weird parents, consider it changed
+	else
+		ptree=$(toptree_for_commit $1) || exit $?
+		if test "$ptree" != "$tree"
+		then
+			return 0   # changed
+		else
+			return 1   # not changed
+		fi
+	fi
+}
+
+# Usage: new_squash_commit OLD_SQUASHED_COMMIT OLD_NONSQUASHED_COMMIT NEW_NONSQUASHED_COMMIT
+new_squash_commit () {
+	assert test $# = 3
+	old="$1"
+	oldsub="$2"
+	newsub="$3"
+	tree=$(toptree_for_commit $newsub) || exit $?
+	if test -n "$old"
+	then
+		squash_msg "$dir" "$oldsub" "$newsub" |
+		git commit-tree "$tree" -p "$old" || exit $?
+	else
+		squash_msg "$dir" "" "$newsub" |
+		git commit-tree "$tree" || exit $?
+	fi
+}
+
+# Usage: copy_or_skip REV TREE NEWPARENTS
+copy_or_skip () {
+	assert test $# = 3
+	rev="$1"
+	tree="$2"
+	newparents="$3"
+	assert test -n "$tree"
+
+	identical=
+	nonidentical=
+	p=
+	gotparents=
+	copycommit=
+	for parent in $newparents
+	do
+		ptree=$(toptree_for_commit $parent) || exit $?
+		test -z "$ptree" && continue
+		if test "$ptree" = "$tree"
+		then
+			# an identical parent could be used in place of this rev.
+			if test -n "$identical"
+			then
+				# if a previous identical parent was found, check whether
+				# one is already an ancestor of the other
+				mergebase=$(git merge-base $identical $parent)
+				if test "$identical" = "$mergebase"
+				then
+					# current identical commit is an ancestor of parent
+					identical="$parent"
+				elif test "$parent" != "$mergebase"
+				then
+					# no common history; commit must be copied
+					copycommit=1
+				fi
+			else
+				# first identical parent detected
+				identical="$parent"
+			fi
+		else
+			nonidentical="$parent"
+		fi
+
+		# sometimes both old parents map to the same newparent;
+		# eliminate duplicates
+		is_new=1
+		for gp in $gotparents
+		do
+			if test "$gp" = "$parent"
+			then
+				is_new=
+				break
+			fi
+		done
+		if test -n "$is_new"
+		then
+			gotparents="$gotparents $parent"
+			p="$p -p $parent"
+		fi
+	done
+
+	if test -n "$identical" && test -n "$nonidentical"
+	then
+		extras=$(git rev-list --count $identical..$nonidentical)
+		if test "$extras" -ne 0
+		then
+			# we need to preserve history along the other branch
+			copycommit=1
+		fi
+	fi
+	if test -n "$identical" && test -z "$copycommit"
+	then
+		echo $identical
+	else
+		copy_commit "$rev" "$tree" "$p" || exit $?
+	fi
+}
+
+# Usage: ensure_clean
+ensure_clean () {
+	assert test $# = 0
+	if ! git diff-index HEAD --exit-code --quiet 2>&1
+	then
+		die "fatal: working tree has modifications.  Cannot add."
+	fi
+	if ! git diff-index --cached HEAD --exit-code --quiet 2>&1
+	then
+		die "fatal: index has modifications.  Cannot add."
+	fi
+}
+
+# Usage: ensure_valid_ref_format REF
+ensure_valid_ref_format () {
+	assert test $# = 1
+	git check-ref-format "refs/heads/$1" ||
+		die "fatal: '$1' does not look like a ref"
+}
+
+# Usage: process_split_commit REV PARENTS
+process_split_commit () {
+	assert test $# = 2
+	local rev="$1"
+	local parents="$2"
+
+	if test $indent -eq 0
+	then
+		revcount=$(($revcount + 1))
+	else
+		# processing commit without normal parent information;
+		# fetch from repo
+		parents=$(git rev-parse "$rev^@")
+		extracount=$(($extracount + 1))
+	fi
+
+	progress "$revcount/$revmax ($createcount) [$extracount]"
+
+	debug "Processing commit: $rev"
+	local indent=$(($indent + 1))
+	exists=$(cache_get "$rev") || exit $?
+	if test -n "$exists"
+	then
+		debug "prior: $exists"
+		return
+	fi
+	createcount=$(($createcount + 1))
+	debug "parents: $parents"
+	check_parents $parents
+	newparents=$(cache_get $parents) || exit $?
+	debug "newparents: $newparents"
+
+	tree=$(subtree_for_commit "$rev" "$dir") || exit $?
+	debug "tree is: $tree"
+
+	# ugly.  is there no better way to tell if this is a subtree
+	# vs. a mainline commit?  Does it matter?
+	if test -z "$tree"
+	then
+		set_notree "$rev"
+		if test -n "$newparents"
+		then
+			cache_set "$rev" "$rev"
+		fi
+		return
+	fi
+
+	newrev=$(copy_or_skip "$rev" "$tree" "$newparents") || exit $?
+	debug "newrev is: $newrev"
+	cache_set "$rev" "$newrev"
+	cache_set latest_new "$newrev"
+	cache_set latest_old "$rev"
+}
+
+# Usage: cmd_add REV
+#    Or: cmd_add REPOSITORY REF
+cmd_add () {
+
+	ensure_clean
+
+	if test $# -eq 1
+	then
+		git rev-parse -q --verify "$1^{commit}" >/dev/null ||
+			die "fatal: '$1' does not refer to a commit"
+
+		cmd_add_commit "$@"
+
+	elif test $# -eq 2
+	then
+		# Technically we could accept a refspec here but we're
+		# just going to turn around and add FETCH_HEAD under the
+		# specified directory.  Allowing a refspec might be
+		# misleading because we won't do anything with any other
+		# branches fetched via the refspec.
+		ensure_valid_ref_format "$2"
+
+		cmd_add_repository "$@"
+	else
+		say >&2 "fatal: parameters were '$*'"
+		die "Provide either a commit or a repository and commit."
+	fi
+}
+
+# Usage: cmd_add_repository REPOSITORY REFSPEC
+cmd_add_repository () {
+	assert test $# = 2
+	echo "git fetch" "$@"
+	repository=$1
+	refspec=$2
+	git fetch "$@" || exit $?
+	cmd_add_commit FETCH_HEAD
+}
+
+# Usage: cmd_add_commit REV
+cmd_add_commit () {
+	# The rev has already been validated by cmd_add(), we just
+	# need to normalize it.
+	assert test $# = 1
+	rev=$(git rev-parse --verify "$1^{commit}") || exit $?
+
+	debug "Adding $dir as '$rev'..."
+	if test -z "$arg_split_rejoin"
+	then
+		# Only bother doing this if this is a genuine 'add',
+		# not a synthetic 'add' from '--rejoin'.
+		git read-tree --prefix="$dir" $rev || exit $?
+	fi
+	git checkout -- "$dir" || exit $?
+	tree=$(git write-tree) || exit $?
+
+	headrev=$(git rev-parse --verify HEAD) || exit $?
+	if test -n "$headrev" && test "$headrev" != "$rev"
+	then
+		headp="-p $headrev"
+	else
+		headp=
+	fi
+
+	if test -n "$arg_addmerge_squash"
+	then
+		rev=$(new_squash_commit "" "" "$rev") || exit $?
+		commit=$(add_squashed_msg "$rev" "$dir" |
+			git commit-tree "$tree" $headp -p "$rev") || exit $?
+	else
+		revp=$(peel_committish "$rev") || exit $?
+		commit=$(add_msg "$dir" $headrev "$rev" |
+			git commit-tree "$tree" $headp -p "$revp") || exit $?
+	fi
+	git reset "$commit" || exit $?
+
+	say >&2 "Added dir '$dir'"
+}
+
+# Usage: cmd_split [REV] [REPOSITORY]
+cmd_split () {
+	if test $# -eq 0
+	then
+		rev=$(git rev-parse HEAD)
+	elif test $# -eq 1 -o $# -eq 2
+	then
+		rev=$(git rev-parse -q --verify "$1^{commit}") ||
+			die "fatal: '$1' does not refer to a commit"
+	else
+		die "fatal: you must provide exactly one revision, and optionnally a repository.  Got: '$*'"
+	fi
+	repository=""
+	if test "$#" = 2
+	then
+		repository="$2"
+	fi
+
+	if test -n "$arg_split_rejoin"
+	then
+		ensure_clean
+	fi
+
+	debug "Splitting $dir..."
+	cache_setup || exit $?
+
+	if test -n "$arg_split_onto"
+	then
+		debug "Reading history for --onto=$arg_split_onto..."
+		git rev-list $arg_split_onto |
+		while read rev
+		do
+			# the 'onto' history is already just the subdir, so
+			# any parent we find there can be used verbatim
+			debug "cache: $rev"
+			cache_set "$rev" "$rev"
+		done || exit $?
+	fi
+
+	unrevs="$(find_existing_splits "$dir" "$rev" "$repository")" || exit $?
+
+	# We can't restrict rev-list to only $dir here, because some of our
+	# parents have the $dir contents the root, and those won't match.
+	# (and rev-list --follow doesn't seem to solve this)
+	grl='git rev-list --topo-order --reverse --parents $rev $unrevs'
+	revmax=$(eval "$grl" | wc -l)
+	revcount=0
+	createcount=0
+	extracount=0
+	eval "$grl" |
+	while read rev parents
+	do
+		process_split_commit "$rev" "$parents"
+	done || exit $?
+
+	latest_new=$(cache_get latest_new) || exit $?
+	if test -z "$latest_new"
+	then
+		die "fatal: no new revisions were found"
+	fi
+
+	if test -n "$arg_split_rejoin"
+	then
+		debug "Merging split branch into HEAD..."
+		latest_old=$(cache_get latest_old) || exit $?
+		arg_addmerge_message="$(rejoin_msg "$dir" "$latest_old" "$latest_new")" || exit $?
+		if test -z "$(find_latest_squash "$dir")"
+		then
+			cmd_add "$latest_new" >&2 || exit $?
+		else
+			cmd_merge "$latest_new" >&2 || exit $?
+		fi
+	fi
+	if test -n "$arg_split_branch"
+	then
+		if rev_exists "refs/heads/$arg_split_branch"
+		then
+			if ! git merge-base --is-ancestor "$arg_split_branch" "$latest_new"
+			then
+				die "fatal: branch '$arg_split_branch' is not an ancestor of commit '$latest_new'."
+			fi
+			action='Updated'
+		else
+			action='Created'
+		fi
+		git update-ref -m 'subtree split' \
+			"refs/heads/$arg_split_branch" "$latest_new" || exit $?
+		say >&2 "$action branch '$arg_split_branch'"
+	fi
+	echo "$latest_new"
+	exit 0
+}
+
+# Usage: cmd_merge REV [REPOSITORY]
+cmd_merge () {
+	test $# -eq 1 -o $# -eq 2 ||
+		die "fatal: you must provide exactly one revision, and optionally a repository. Got: '$*'"
+	rev=$(git rev-parse -q --verify "$1^{commit}") ||
+		die "fatal: '$1' does not refer to a commit"
+	repository=""
+	if test "$#" = 2
+	then
+		repository="$2"
+	fi
+	ensure_clean
+
+	if test -n "$arg_addmerge_squash"
+	then
+		first_split="$(find_latest_squash "$dir" "$repository")" || exit $?
+		if test -z "$first_split"
+		then
+			die "fatal: can't squash-merge: '$dir' was never added."
+		fi
+		set $first_split
+		old=$1
+		sub=$2
+		if test "$sub" = "$rev"
+		then
+			say >&2 "Subtree is already at commit $rev."
+			exit 0
+		fi
+		new=$(new_squash_commit "$old" "$sub" "$rev") || exit $?
+		debug "New squash commit: $new"
+		rev="$new"
+	fi
+
+	if test -n "$arg_addmerge_message"
+	then
+		git merge --no-ff -Xsubtree="$arg_prefix" \
+			--message="$arg_addmerge_message" "$rev"
+	else
+		git merge --no-ff -Xsubtree="$arg_prefix" $rev
+	fi
+}
+
+# Usage: cmd_pull REPOSITORY REMOTEREF
+cmd_pull () {
+	if test $# -ne 2
+	then
+		die "fatal: you must provide <repository> <ref>"
+	fi
+	repository="$1"
+	ref="$2"
+	ensure_clean
+	ensure_valid_ref_format "$ref"
+	git fetch "$repository" "$ref" || exit $?
+	cmd_merge FETCH_HEAD "$repository"
+}
+
+# Usage: cmd_push REPOSITORY [+][LOCALREV:]REMOTEREF
+cmd_push () {
+	if test $# -ne 2
+	then
+		die "fatal: you must provide <repository> <refspec>"
+	fi
+	if test -e "$dir"
+	then
+		repository=$1
+		refspec=${2#+}
+		remoteref=${refspec#*:}
+		if test "$remoteref" = "$refspec"
+		then
+			localrevname_presplit=HEAD
+		else
+			localrevname_presplit=${refspec%%:*}
+		fi
+		ensure_valid_ref_format "$remoteref"
+		localrev_presplit=$(git rev-parse -q --verify "$localrevname_presplit^{commit}") ||
+			die "fatal: '$localrevname_presplit' does not refer to a commit"
+
+		echo "git push using: " "$repository" "$refspec"
+		localrev=$(cmd_split "$localrev_presplit" "$repository") || die
+		git push "$repository" "$localrev":"refs/heads/$remoteref"
+	else
+		die "fatal: '$dir' must already exist. Try 'git subtree add'."
+	fi
+}
+
+main "$@"
diff --git a/contrib/subtree/git-subtree.txt b/contrib/subtree/git-subtree.txt
new file mode 100644
index 0000000..004abf4
--- /dev/null
+++ b/contrib/subtree/git-subtree.txt
@@ -0,0 +1,353 @@
+git-subtree(1)
+==============
+
+NAME
+----
+git-subtree - Merge subtrees together and split repository into subtrees
+
+
+SYNOPSIS
+--------
+[verse]
+'git subtree' [<options>] -P <prefix> add <local-commit>
+'git subtree' [<options>] -P <prefix> add <repository> <remote-ref>
+'git subtree' [<options>] -P <prefix> merge <local-commit> [<repository>]
+'git subtree' [<options>] -P <prefix> split [<local-commit>]
+
+[verse]
+'git subtree' [<options>] -P <prefix> pull <repository> <remote-ref>
+'git subtree' [<options>] -P <prefix> push <repository> <refspec>
+
+DESCRIPTION
+-----------
+Subtrees allow subprojects to be included within a subdirectory
+of the main project, optionally including the subproject's
+entire history.
+
+For example, you could include the source code for a library
+as a subdirectory of your application.
+
+Subtrees are not to be confused with submodules, which are meant for
+the same task. Unlike submodules, subtrees do not need any special
+constructions (like '.gitmodules' files or gitlinks) be present in
+your repository, and do not force end-users of your
+repository to do anything special or to understand how subtrees
+work. A subtree is just a subdirectory that can be
+committed to, branched, and merged along with your project in
+any way you want.
+
+They are also not to be confused with using the subtree merge
+strategy. The main difference is that, besides merging
+the other project as a subdirectory, you can also extract the
+entire history of a subdirectory from your project and make it
+into a standalone project. Unlike the subtree merge strategy
+you can alternate back and forth between these
+two operations. If the standalone library gets updated, you can
+automatically merge the changes into your project; if you
+update the library inside your project, you can "split" the
+changes back out again and merge them back into the library
+project.
+
+For example, if a library you made for one application ends up being
+useful elsewhere, you can extract its entire history and publish
+that as its own git repository, without accidentally
+intermingling the history of your application project.
+
+[TIP]
+In order to keep your commit messages clean, we recommend that
+people split their commits between the subtrees and the main
+project as much as possible.  That is, if you make a change that
+affects both the library and the main application, commit it in
+two pieces.  That way, when you split the library commits out
+later, their descriptions will still make sense.  But if this
+isn't important to you, it's not *necessary*.  'git subtree' will
+simply leave out the non-library-related parts of the commit
+when it splits it out into the subproject later.
+
+
+COMMANDS
+--------
+add <local-commit>::
+add <repository> <remote-ref>::
+	Create the <prefix> subtree by importing its contents
+	from the given <local-commit> or <repository> and <remote-ref>.
+	A new commit is created	automatically, joining the imported
+	project's history with your own.  With '--squash', import
+	only a single commit from the subproject, rather than its
+	entire history.
+
+merge <local-commit> [<repository>]::
+	Merge recent changes up to <local-commit> into the <prefix>
+	subtree.  As with normal 'git merge', this doesn't
+	remove your own local changes; it just merges those
+	changes into the latest <local-commit>.  With '--squash',
+	create only one commit that contains all the changes,
+	rather than merging in the entire history.
++
+If you use '--squash', the merge direction doesn't always have to be
+forward; you can use this command to go back in time from v2.5 to v2.4,
+for example.  If your merge introduces a conflict, you can resolve it in
+the usual ways.
++
+When using '--squash', and the previous merge with '--squash' merged an
+annotated tag of the subtree repository, that tag needs to be available locally.
+If <repository> is given, a missing tag will automatically be fetched from that
+repository.
+
+split [<local-commit>] [<repository>]::
+	Extract a new, synthetic project history from the
+	history of the <prefix> subtree of <local-commit>, or of
+	HEAD if no <local-commit> is given.  The new history
+	includes only the commits (including merges) that
+	affected <prefix>, and each of those commits now has the
+	contents of <prefix> at the root of the project instead
+	of in a subdirectory.  Thus, the newly created history
+	is suitable for export as a separate git repository.
++
+After splitting successfully, a single commit ID is printed to stdout.
+This corresponds to the HEAD of the newly created tree, which you can
+manipulate however you want.
++
+Repeated splits of exactly the same history are guaranteed to be
+identical (i.e. to produce the same commit IDs) as long as the
+settings passed to 'split' (such as '--annotate') are the same.
+Because of this, if you add new commits and then re-split, the new
+commits will be attached as commits on top of the history you
+generated last time, so 'git merge' and friends will work as expected.
++
+When a previous merge with '--squash' merged an annotated tag of the
+subtree repository, that tag needs to be available locally.
+If <repository> is given, a missing tag will automatically be fetched from that
+repository.
+
+pull <repository> <remote-ref>::
+	Exactly like 'merge', but parallels 'git pull' in that
+	it fetches the given ref from the specified remote
+	repository.
+
+push <repository> [+][<local-commit>:]<remote-ref>::
+	Does a 'split' using the <prefix> subtree of <local-commit>
+	and then does a 'git push' to push the result to the
+	<repository> and <remote-ref>.  This can be used to push your
+	subtree to different branches of the remote repository.  Just
+	as with 'split', if no <local-commit> is given, then HEAD is
+	used.  The optional leading '+' is ignored.
+
+OPTIONS FOR ALL COMMANDS
+------------------------
+-q::
+--quiet::
+	Suppress unnecessary output messages on stderr.
+
+-d::
+--debug::
+	Produce even more unnecessary output messages on stderr.
+
+-P <prefix>::
+--prefix=<prefix>::
+	Specify the path in the repository to the subtree you
+	want to manipulate.  This option is mandatory
+	for all commands.
+
+OPTIONS FOR 'add' AND 'merge' (ALSO: 'pull', 'split --rejoin', AND 'push --rejoin')
+-----------------------------------------------------------------------------------
+These options for 'add' and 'merge' may also be given to 'pull' (which
+wraps 'merge'), 'split --rejoin' (which wraps either 'add' or 'merge'
+as appropriate), and 'push --rejoin' (which wraps 'split --rejoin').
+
+--squash::
+	Instead of merging the entire history from the subtree project, produce
+	only a single commit that contains all the differences you want to
+	merge, and then merge that new commit into your project.
++
+Using this option helps to reduce log clutter. People rarely want to see
+every change that happened between v1.0 and v1.1 of the library they're
+using, since none of the interim versions were ever included in their
+application.
++
+Using '--squash' also helps avoid problems when the same subproject is
+included multiple times in the same project, or is removed and then
+re-added.  In such a case, it doesn't make sense to combine the
+histories anyway, since it's unclear which part of the history belongs
+to which subtree.
++
+Furthermore, with '--squash', you can switch back and forth between
+different versions of a subtree, rather than strictly forward.  'git
+subtree merge --squash' always adjusts the subtree to match the exactly
+specified commit, even if getting to that commit would require undoing
+some changes that were added earlier.
++
+Whether or not you use '--squash', changes made in your local repository
+remain intact and can be later split and send upstream to the
+subproject.
+
+-m <message>::
+--message=<message>::
+	Specify <message> as the commit message for the merge commit.
+
+OPTIONS FOR 'split' (ALSO: 'push')
+----------------------------------
+These options for 'split' may also be given to 'push' (which wraps
+'split').
+
+--annotate=<annotation>::
+	When generating synthetic history, add <annotation> as a prefix to each
+	commit message.  Since we're creating new commits with the same commit
+	message, but possibly different content, from the original commits, this
+	can help to differentiate them and avoid confusion.
++
+Whenever you split, you need to use the same <annotation>, or else you
+don't have a guarantee that the new re-created history will be identical
+to the old one.  That will prevent merging from working correctly.  git
+subtree tries to make it work anyway, particularly if you use '--rejoin',
+but it may not always be effective.
+
+-b <branch>::
+--branch=<branch>::
+	After generating the synthetic history, create a new branch called
+	<branch> that contains the new history.  This is suitable for immediate
+	pushing upstream.  <branch> must not already exist.
+
+--ignore-joins::
+	If you use '--rejoin', git subtree attempts to optimize its history
+	reconstruction to generate only the new commits since the last
+	'--rejoin'.  '--ignore-joins' disables this behavior, forcing it to
+	regenerate the entire history.  In a large project, this can take a long
+	time.
+
+--onto=<onto>::
+	If your subtree was originally imported using something other than git
+	subtree, its history may not match what git subtree is expecting.  In
+	that case, you can specify the commit ID <onto> that corresponds to the
+	first revision of the subproject's history that was imported into your
+	project, and git subtree will attempt to build its history from there.
++
+If you used 'git subtree add', you should never need this option.
+
+--rejoin::
+	After splitting, merge the newly created synthetic history back into
+	your main project.  That way, future splits can search only the part of
+	history that has been added since the most recent '--rejoin'.
++
+If your split commits end up merged into the upstream subproject, and
+then you want to get the latest upstream version, this will allow git's
+merge algorithm to more intelligently avoid conflicts (since it knows
+these synthetic commits are already part of the upstream repository).
++
+Unfortunately, using this option results in 'git log' showing an extra
+copy of every new commit that was created (the original, and the
+synthetic one).
++
+If you do all your merges with '--squash', make sure you also use
+'--squash' when you 'split --rejoin'.
+
+
+EXAMPLE 1. 'add' command
+------------------------
+Let's assume that you have a local repository that you would like
+to add an external vendor library to. In this case we will add the
+git-subtree repository as a subdirectory of your already existing
+git-extensions repository in ~/git-extensions/:
+
+	$ git subtree add --prefix=git-subtree --squash \
+		git://github.com/apenwarr/git-subtree.git master
+
+'master' needs to be a valid remote ref and can be a different branch
+name
+
+You can omit the '--squash' flag, but doing so will increase the number
+of commits that are included in your local repository.
+
+We now have a ~/git-extensions/git-subtree directory containing code
+from the master branch of git://github.com/apenwarr/git-subtree.git
+in our git-extensions repository.
+
+EXAMPLE 2. Extract a subtree using 'commit', 'merge' and 'pull'
+---------------------------------------------------------------
+Let's use the repository for the git source code as an example.
+First, get your own copy of the git.git repository:
+
+	$ git clone git://git.kernel.org/pub/scm/git/git.git test-git
+	$ cd test-git
+
+gitweb (commit 1130ef3) was merged into git as of commit
+0a8f4f0, after which it was no longer maintained separately.
+But imagine it had been maintained separately, and we wanted to
+extract git's changes to gitweb since that time, to share with
+the upstream.  You could do this:
+
+	$ git subtree split --prefix=gitweb --annotate='(split) ' \
+        	0a8f4f0^.. --onto=1130ef3 --rejoin \
+        	--branch gitweb-latest
+        $ gitk gitweb-latest
+        $ git push git@github.com:whatever/gitweb.git gitweb-latest:master
+
+(We use '0a8f4f0^..' because that means "all the changes from
+0a8f4f0 to the current version, including 0a8f4f0 itself.")
+
+If gitweb had originally been merged using 'git subtree add' (or
+a previous split had already been done with '--rejoin' specified)
+then you can do all your splits without having to remember any
+weird commit IDs:
+
+	$ git subtree split --prefix=gitweb --annotate='(split) ' --rejoin \
+		--branch gitweb-latest2
+
+And you can merge changes back in from the upstream project just
+as easily:
+
+	$ git subtree pull --prefix=gitweb \
+		git@github.com:whatever/gitweb.git master
+
+Or, using '--squash', you can actually rewind to an earlier
+version of gitweb:
+
+	$ git subtree merge --prefix=gitweb --squash gitweb-latest~10
+
+Then make some changes:
+
+	$ date >gitweb/myfile
+	$ git add gitweb/myfile
+	$ git commit -m 'created myfile'
+
+And fast forward again:
+
+	$ git subtree merge --prefix=gitweb --squash gitweb-latest
+
+And notice that your change is still intact:
+
+	$ ls -l gitweb/myfile
+
+And you can split it out and look at your changes versus
+the standard gitweb:
+
+	git log gitweb-latest..$(git subtree split --prefix=gitweb)
+
+EXAMPLE 3. Extract a subtree using a branch
+-------------------------------------------
+Suppose you have a source directory with many files and
+subdirectories, and you want to extract the lib directory to its own
+git project. Here's a short way to do it:
+
+First, make the new repository wherever you want:
+
+	$ <go to the new location>
+	$ git init --bare
+
+Back in your original directory:
+
+	$ git subtree split --prefix=lib --annotate="(split)" -b split
+
+Then push the new branch onto the new empty repository:
+
+	$ git push <new-repo> split:master
+
+
+AUTHOR
+------
+Written by Avery Pennarun <apenwarr@gmail.com>
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/contrib/subtree/t/Makefile b/contrib/subtree/t/Makefile
new file mode 100644
index 0000000..093399c
--- /dev/null
+++ b/contrib/subtree/t/Makefile
@@ -0,0 +1,85 @@
+# Run tests
+#
+# Copyright (c) 2005 Junio C Hamano
+#
+
+-include ../../../config.mak.autogen
+-include ../../../config.mak
+
+#GIT_TEST_OPTS=--verbose --debug
+SHELL_PATH ?= $(SHELL)
+PERL_PATH ?= /usr/bin/perl
+TAR ?= $(TAR)
+RM ?= rm -f
+PROVE ?= prove
+DEFAULT_TEST_TARGET ?= test
+TEST_LINT ?= test-lint
+
+ifdef TEST_OUTPUT_DIRECTORY
+TEST_RESULTS_DIRECTORY = $(TEST_OUTPUT_DIRECTORY)/test-results
+else
+TEST_RESULTS_DIRECTORY = ../../../t/test-results
+endif
+
+# Shell quote;
+SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
+PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
+TEST_RESULTS_DIRECTORY_SQ = $(subst ','\'',$(TEST_RESULTS_DIRECTORY))
+
+T = $(sort $(wildcard t[0-9][0-9][0-9][0-9]-*.sh))
+TSVN = $(sort $(wildcard t91[0-9][0-9]-*.sh))
+TGITWEB = $(sort $(wildcard t95[0-9][0-9]-*.sh))
+THELPERS = $(sort $(filter-out $(T),$(wildcard *.sh)))
+
+all: $(DEFAULT_TEST_TARGET)
+
+test: pre-clean $(TEST_LINT)
+	$(MAKE) aggregate-results-and-cleanup
+
+prove: pre-clean $(TEST_LINT)
+	@echo "*** prove ***"; GIT_CONFIG=.git/config $(PROVE) --exec '$(SHELL_PATH_SQ)' $(GIT_PROVE_OPTS) $(T) :: $(GIT_TEST_OPTS)
+	$(MAKE) clean-except-prove-cache
+
+$(T):
+	@echo "*** $@ ***"; GIT_CONFIG=.git/config '$(SHELL_PATH_SQ)' $@ $(GIT_TEST_OPTS)
+
+pre-clean:
+	$(RM) -r '$(TEST_RESULTS_DIRECTORY_SQ)'
+
+clean-except-prove-cache:
+	$(RM) -r 'trash directory'.*
+	$(RM) -r valgrind/bin
+
+clean: clean-except-prove-cache
+	$(RM) -r '$(TEST_RESULTS_DIRECTORY_SQ)'
+	$(RM) .prove
+
+test-lint: test-lint-duplicates test-lint-executable test-lint-shell-syntax
+
+test-lint-duplicates:
+	@dups=`echo $(T) | tr ' ' '\n' | sed 's/-.*//' | sort | uniq -d` && \
+		test -z "$$dups" || { \
+		echo >&2 "duplicate test numbers:" $$dups; exit 1; }
+
+test-lint-executable:
+	@bad=`for i in $(T); do test -x "$$i" || echo $$i; done` && \
+		test -z "$$bad" || { \
+		echo >&2 "non-executable tests:" $$bad; exit 1; }
+
+test-lint-shell-syntax:
+	@'$(PERL_PATH_SQ)' ../../../t/check-non-portable-shell.pl $(T) $(THELPERS)
+
+aggregate-results-and-cleanup: $(T)
+	$(MAKE) aggregate-results
+	$(MAKE) clean
+
+aggregate-results:
+	@'$(SHELL_PATH_SQ)' ../../../t/aggregate-results.sh '$(TEST_RESULTS_DIRECTORY_SQ)'
+
+valgrind:
+	$(MAKE) GIT_TEST_OPTS="$(GIT_TEST_OPTS) --valgrind"
+
+test-results:
+	mkdir -p test-results
+
+.PHONY: pre-clean $(T) aggregate-results clean valgrind
diff --git a/contrib/subtree/t/t7900-subtree.sh b/contrib/subtree/t/t7900-subtree.sh
new file mode 100755
index 0000000..49a21dd
--- /dev/null
+++ b/contrib/subtree/t/t7900-subtree.sh
@@ -0,0 +1,1526 @@
+#!/bin/sh
+#
+# Copyright (c) 2012 Avery Pennaraum
+# Copyright (c) 2015 Alexey Shumkin
+#
+test_description='Basic porcelain support for subtrees
+
+This test verifies the basic operation of the add, merge, split, pull,
+and push subcommands of git subtree.
+'
+
+TEST_DIRECTORY=$(pwd)/../../../t
+. "$TEST_DIRECTORY"/test-lib.sh
+
+# Use our own wrapper around test-lib.sh's test_create_repo, in order
+# to set log.date=relative.  `git subtree` parses the output of `git
+# log`, and so it must be careful to not be affected by settings that
+# change the `git log` output.  We test this by setting
+# log.date=relative for every repo in the tests.
+subtree_test_create_repo () {
+	test_create_repo "$1" &&
+	git -C "$1" config log.date relative
+}
+
+test_create_commit () (
+	repo=$1 &&
+	commit=$2 &&
+	cd "$repo" &&
+	mkdir -p "$(dirname "$commit")" \
+	|| error "Could not create directory for commit"
+	echo "$commit" >"$commit" &&
+	git add "$commit" || error "Could not add commit"
+	git commit -m "$commit" || error "Could not commit"
+)
+
+test_wrong_flag() {
+	test_must_fail "$@" >out 2>err &&
+	test_must_be_empty out &&
+	grep "flag does not make sense with" err
+}
+
+last_commit_subject () {
+	git log --pretty=format:%s -1
+}
+
+# Upon 'git subtree add|merge --squash' of an annotated tag,
+# pre-2.32.0 versions of 'git subtree' would write the hash of the tag
+# (sub1 below), instead of the commit (sub1^{commit}) in the
+# "git-subtree-split" trailer.
+# We immitate this behaviour below using a replace ref.
+# This function creates 3 repositories:
+# - $1
+# - $1-sub (added as subtree "sub" in $1)
+# - $1-clone (clone of $1)
+test_create_pre2_32_repo () {
+	subtree_test_create_repo "$1" &&
+	subtree_test_create_repo "$1-sub" &&
+	test_commit -C "$1" main1 &&
+	test_commit -C "$1-sub" --annotate sub1 &&
+	git -C "$1" subtree add --prefix="sub" --squash "../$1-sub" sub1 &&
+	tag=$(git -C "$1" rev-parse FETCH_HEAD) &&
+	commit=$(git -C "$1" rev-parse FETCH_HEAD^{commit}) &&
+	git -C "$1" log -1 --format=%B HEAD^2 >msg &&
+	test_commit -C "$1-sub" --annotate sub2 &&
+	git clone --no-local "$1" "$1-clone" &&
+	new_commit=$(cat msg | sed -e "s/$commit/$tag/" | git -C "$1-clone" commit-tree HEAD^2^{tree}) &&
+	git -C "$1-clone" replace HEAD^2 $new_commit
+}
+
+test_expect_success 'shows short help text for -h' '
+	test_expect_code 129 git subtree -h >out 2>err &&
+	test_must_be_empty err &&
+	grep -e "^ *or: git subtree pull" out &&
+	grep -F -e "--[no-]annotate" out
+'
+
+#
+# Tests for 'git subtree add'
+#
+
+test_expect_success 'no merge from non-existent subtree' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		test_must_fail git subtree merge --prefix="sub dir" FETCH_HEAD
+	)
+'
+
+test_expect_success 'no pull from non-existent subtree' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		test_must_fail git subtree pull --prefix="sub dir" ./"sub proj" HEAD
+	)
+'
+
+test_expect_success 'add rejects flags for split' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --annotate=foo FETCH_HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --branch=foo FETCH_HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --ignore-joins FETCH_HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --onto=foo FETCH_HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --rejoin FETCH_HEAD
+	)
+'
+
+test_expect_success 'add subproj as subtree into sub dir/ with --prefix' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD &&
+		test "$(last_commit_subject)" = "Add '\''sub dir/'\'' from commit '\''$(git rev-parse FETCH_HEAD)'\''"
+	)
+'
+
+test_expect_success 'add subproj as subtree into sub dir/ with --prefix and --message' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" --message="Added subproject" FETCH_HEAD &&
+		test "$(last_commit_subject)" = "Added subproject"
+	)
+'
+
+test_expect_success 'add subproj as subtree into sub dir/ with --prefix as -P and --message as -m' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add -P "sub dir" -m "Added subproject" FETCH_HEAD &&
+		test "$(last_commit_subject)" = "Added subproject"
+	)
+'
+
+test_expect_success 'add subproj as subtree into sub dir/ with --squash and --prefix and --message' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" --message="Added subproject with squash" --squash FETCH_HEAD &&
+		test "$(last_commit_subject)" = "Added subproject with squash"
+	)
+'
+
+#
+# Tests for 'git subtree merge'
+#
+
+test_expect_success 'merge rejects flags for split' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --annotate=foo FETCH_HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --branch=foo FETCH_HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --ignore-joins FETCH_HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --onto=foo FETCH_HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --rejoin FETCH_HEAD
+	)
+'
+
+test_expect_success 'merge new subproj history into sub dir/ with --prefix' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		test "$(last_commit_subject)" = "Merge commit '\''$(git rev-parse FETCH_HEAD)'\''"
+	)
+'
+
+test_expect_success 'merge new subproj history into sub dir/ with --prefix and --message' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" --message="Merged changes from subproject" FETCH_HEAD &&
+		test "$(last_commit_subject)" = "Merged changes from subproject"
+	)
+'
+
+test_expect_success 'merge new subproj history into sub dir/ with --squash and --prefix and --message' '
+	subtree_test_create_repo "$test_count/sub proj" &&
+	subtree_test_create_repo "$test_count" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" --message="Merged changes from subproject using squash" --squash FETCH_HEAD &&
+		test "$(last_commit_subject)" = "Merged changes from subproject using squash"
+	)
+'
+
+test_expect_success 'merge the added subproj again, should do nothing' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD &&
+		# this shouldn not actually do anything, since FETCH_HEAD
+		# is already a parent
+		result=$(git merge -s ours -m "merge -s -ours" FETCH_HEAD) &&
+		test "${result}" = "Already up to date."
+	)
+'
+
+test_expect_success 'merge new subproj history into subdir/ with a slash appended to the argument of --prefix' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/subproj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/subproj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./subproj HEAD &&
+		git subtree add --prefix=subdir/ FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/subproj" sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./subproj HEAD &&
+		git subtree merge --prefix=subdir/ FETCH_HEAD &&
+		test "$(last_commit_subject)" = "Merge commit '\''$(git rev-parse FETCH_HEAD)'\''"
+	)
+'
+
+test_expect_success 'merge with --squash after annotated tag was added/merged with --squash pre-v2.32.0 ' '
+	test_create_pre2_32_repo "$test_count" &&
+	git -C "$test_count-clone" fetch "../$test_count-sub" sub2  &&
+	test_must_fail git -C "$test_count-clone" subtree merge --prefix="sub" --squash FETCH_HEAD &&
+	git -C "$test_count-clone" subtree merge --prefix="sub" --squash FETCH_HEAD  "../$test_count-sub"
+'
+
+#
+# Tests for 'git subtree split'
+#
+
+test_expect_success 'split requires option --prefix' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD &&
+		echo "fatal: you must provide the --prefix option." >expected &&
+		test_must_fail git subtree split >actual 2>&1 &&
+		test_debug "printf '"expected: "'" &&
+		test_debug "cat expected" &&
+		test_debug "printf '"actual: "'" &&
+		test_debug "cat actual" &&
+		test_cmp expected actual
+	)
+'
+
+test_expect_success 'split requires path given by option --prefix must exist' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD &&
+		echo "fatal: '\''non-existent-directory'\'' does not exist; use '\''git subtree add'\''" >expected &&
+		test_must_fail git subtree split --prefix=non-existent-directory >actual 2>&1 &&
+		test_debug "printf '"expected: "'" &&
+		test_debug "cat expected" &&
+		test_debug "printf '"actual: "'" &&
+		test_debug "cat actual" &&
+		test_cmp expected actual
+	)
+'
+
+test_expect_success 'split rejects flags for add' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		test_wrong_flag git subtree split --prefix="sub dir" --squash &&
+		test_wrong_flag git subtree split --prefix="sub dir" --message=foo
+	)
+'
+
+test_expect_success 'split sub dir/ with --rejoin' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		git subtree split --prefix="sub dir" --annotate="*" --rejoin &&
+		test "$(last_commit_subject)" = "Split '\''sub dir/'\'' into commit '\''$split_hash'\''"
+	)
+'
+
+test_expect_success 'split sub dir/ with --rejoin from scratch' '
+	subtree_test_create_repo "$test_count" &&
+	test_create_commit "$test_count" main1 &&
+	(
+		cd "$test_count" &&
+		mkdir "sub dir" &&
+		echo file >"sub dir"/file &&
+		git add "sub dir/file" &&
+		git commit -m"sub dir file" &&
+		split_hash=$(git subtree split --prefix="sub dir" --rejoin) &&
+		git subtree split --prefix="sub dir" --rejoin &&
+		test "$(last_commit_subject)" = "Split '\''sub dir/'\'' into commit '\''$split_hash'\''"
+	)
+'
+
+test_expect_success 'split sub dir/ with --rejoin and --message' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		git subtree split --prefix="sub dir" --message="Split & rejoin" --annotate="*" --rejoin &&
+		test "$(last_commit_subject)" = "Split & rejoin"
+	)
+'
+
+test_expect_success 'split "sub dir"/ with --rejoin and --squash' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" --squash FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git subtree pull --prefix="sub dir" --squash ./"sub proj" HEAD &&
+		MAIN=$(git rev-parse --verify HEAD) &&
+		SUB=$(git -C "sub proj" rev-parse --verify HEAD) &&
+
+		SPLIT=$(git subtree split --prefix="sub dir" --annotate="*" --rejoin --squash) &&
+
+		test_must_fail git merge-base --is-ancestor $SUB HEAD &&
+		test_must_fail git merge-base --is-ancestor $SPLIT HEAD &&
+		git rev-list HEAD ^$MAIN >commit-list &&
+		test_line_count = 2 commit-list &&
+		test "$(git rev-parse --verify HEAD:)"           = "$(git rev-parse --verify $MAIN:)" &&
+		test "$(git rev-parse --verify HEAD:"sub dir")"  = "$(git rev-parse --verify $SPLIT:)" &&
+		test "$(git rev-parse --verify HEAD^1)"          = $MAIN &&
+		test "$(git rev-parse --verify HEAD^2)"         != $SPLIT &&
+		test "$(git rev-parse --verify HEAD^2:)"         = "$(git rev-parse --verify $SPLIT:)" &&
+		test "$(last_commit_subject)" = "Split '\''sub dir/'\'' into commit '\''$SPLIT'\''"
+	)
+'
+
+test_expect_success 'split then pull "sub dir"/ with --rejoin and --squash' '
+	# 1. "add"
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	git -C "$test_count" subtree --prefix="sub dir" add --squash ./"sub proj" HEAD &&
+
+	# 2. commit from parent
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+
+	# 3. "split --rejoin --squash"
+	git -C "$test_count" subtree --prefix="sub dir" split --rejoin --squash &&
+
+	# 4. "pull --squash"
+	test_create_commit "$test_count/sub proj" sub2 &&
+	git -C "$test_count" subtree -d --prefix="sub dir" pull --squash ./"sub proj" HEAD &&
+
+	test_must_fail git merge-base HEAD FETCH_HEAD
+'
+
+test_expect_success 'split "sub dir"/ with --branch' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br &&
+		test "$(git rev-parse subproj-br)" = "$split_hash"
+	)
+'
+
+test_expect_success 'check hash of split' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br &&
+		test "$(git rev-parse subproj-br)" = "$split_hash" &&
+		# Check hash of split
+		new_hash=$(git rev-parse subproj-br^2) &&
+		(
+			cd ./"sub proj" &&
+			subdir_hash=$(git rev-parse HEAD) &&
+			test "$new_hash" = "$subdir_hash"
+		)
+	)
+'
+
+test_expect_success 'split "sub dir"/ with --branch for an existing branch' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git branch subproj-br FETCH_HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br &&
+		test "$(git rev-parse subproj-br)" = "$split_hash"
+	)
+'
+
+test_expect_success 'split "sub dir"/ with --branch for an incompatible branch' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git branch init HEAD &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		test_must_fail git subtree split --prefix="sub dir" --branch init
+	)
+'
+
+test_expect_success 'split after annotated tag was added/merged with --squash pre-v2.32.0' '
+	test_create_pre2_32_repo "$test_count" &&
+	test_must_fail git -C "$test_count-clone" subtree split --prefix="sub" HEAD &&
+	git -C "$test_count-clone" subtree split --prefix="sub" HEAD "../$test_count-sub"
+'
+
+#
+# Tests for 'git subtree pull'
+#
+
+test_expect_success 'pull requires option --prefix' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		test_must_fail git subtree pull ./"sub proj" HEAD >out 2>err &&
+
+		echo "fatal: you must provide the --prefix option." >expected &&
+		test_must_be_empty out &&
+		test_cmp expected err
+	)
+'
+
+test_expect_success 'pull requires path given by option --prefix must exist' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		test_must_fail git subtree pull --prefix="sub dir" ./"sub proj" HEAD >out 2>err &&
+
+		echo "fatal: '\''sub dir'\'' does not exist; use '\''git subtree add'\''" >expected &&
+		test_must_be_empty out &&
+		test_cmp expected err
+	)
+'
+
+test_expect_success 'pull basic operation' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		exp=$(git -C "sub proj" rev-parse --verify HEAD:) &&
+		git subtree pull --prefix="sub dir" ./"sub proj" HEAD &&
+		act=$(git rev-parse --verify HEAD:"sub dir") &&
+		test "$act" = "$exp"
+	)
+'
+
+test_expect_success 'pull rejects flags for split' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		test_must_fail git subtree pull --prefix="sub dir" --annotate=foo ./"sub proj" HEAD &&
+		test_must_fail git subtree pull --prefix="sub dir" --branch=foo ./"sub proj" HEAD &&
+		test_must_fail git subtree pull --prefix="sub dir" --ignore-joins ./"sub proj" HEAD &&
+		test_must_fail git subtree pull --prefix="sub dir" --onto=foo ./"sub proj" HEAD &&
+		test_must_fail git subtree pull --prefix="sub dir" --rejoin ./"sub proj" HEAD
+	)
+'
+
+test_expect_success 'pull with --squash after annotated tag was added/merged with --squash pre-v2.32.0 ' '
+	test_create_pre2_32_repo "$test_count" &&
+	git -C "$test_count-clone" subtree -d pull --prefix="sub" --squash "../$test_count-sub" sub2
+'
+
+#
+# Tests for 'git subtree push'
+#
+
+test_expect_success 'push requires option --prefix' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD &&
+		echo "fatal: you must provide the --prefix option." >expected &&
+		test_must_fail git subtree push "./sub proj" from-mainline >actual 2>&1 &&
+		test_debug "printf '"expected: "'" &&
+		test_debug "cat expected" &&
+		test_debug "printf '"actual: "'" &&
+		test_debug "cat actual" &&
+		test_cmp expected actual
+	)
+'
+
+test_expect_success 'push requires path given by option --prefix must exist' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD &&
+		echo "fatal: '\''non-existent-directory'\'' does not exist; use '\''git subtree add'\''" >expected &&
+		test_must_fail git subtree push --prefix=non-existent-directory "./sub proj" from-mainline >actual 2>&1 &&
+		test_debug "printf '"expected: "'" &&
+		test_debug "cat expected" &&
+		test_debug "printf '"actual: "'" &&
+		test_debug "cat actual" &&
+		test_cmp expected actual
+	)
+'
+
+test_expect_success 'push rejects flags for add' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		test_wrong_flag git subtree split --prefix="sub dir" --squash ./"sub proj" from-mainline &&
+		test_wrong_flag git subtree split --prefix="sub dir" --message=foo ./"sub proj" from-mainline
+	)
+'
+
+test_expect_success 'push basic operation' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		before=$(git rev-parse --verify HEAD) &&
+		split_hash=$(git subtree split --prefix="sub dir") &&
+		git subtree push --prefix="sub dir" ./"sub proj" from-mainline &&
+		test "$before" = "$(git rev-parse --verify HEAD)" &&
+		test "$split_hash" = "$(git -C "sub proj" rev-parse --verify refs/heads/from-mainline)"
+	)
+'
+
+test_expect_success 'push sub dir/ with --rejoin' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		git subtree push --prefix="sub dir" --annotate="*" --rejoin ./"sub proj" from-mainline &&
+		test "$(last_commit_subject)" = "Split '\''sub dir/'\'' into commit '\''$split_hash'\''" &&
+		test "$split_hash" = "$(git -C "sub proj" rev-parse --verify refs/heads/from-mainline)"
+	)
+'
+
+test_expect_success 'push sub dir/ with --rejoin from scratch' '
+	subtree_test_create_repo "$test_count" &&
+	test_create_commit "$test_count" main1 &&
+	(
+		cd "$test_count" &&
+		mkdir "sub dir" &&
+		echo file >"sub dir"/file &&
+		git add "sub dir/file" &&
+		git commit -m"sub dir file" &&
+		split_hash=$(git subtree split --prefix="sub dir" --rejoin) &&
+		git init --bare "sub proj.git" &&
+		git subtree push --prefix="sub dir" --rejoin ./"sub proj.git" from-mainline &&
+		test "$(last_commit_subject)" = "Split '\''sub dir/'\'' into commit '\''$split_hash'\''" &&
+		test "$split_hash" = "$(git -C "sub proj.git" rev-parse --verify refs/heads/from-mainline)"
+	)
+'
+
+test_expect_success 'push sub dir/ with --rejoin and --message' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		git subtree push --prefix="sub dir" --message="Split & rejoin" --annotate="*" --rejoin ./"sub proj" from-mainline &&
+		test "$(last_commit_subject)" = "Split & rejoin" &&
+		split_hash="$(git rev-parse --verify HEAD^2)" &&
+		test "$split_hash" = "$(git -C "sub proj" rev-parse --verify refs/heads/from-mainline)"
+	)
+'
+
+test_expect_success 'push "sub dir"/ with --rejoin and --squash' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" --squash FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git subtree pull --prefix="sub dir" --squash ./"sub proj" HEAD &&
+		MAIN=$(git rev-parse --verify HEAD) &&
+		SUB=$(git -C "sub proj" rev-parse --verify HEAD) &&
+
+		SPLIT=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		git subtree push --prefix="sub dir" --annotate="*" --rejoin --squash ./"sub proj" from-mainline &&
+
+		test_must_fail git merge-base --is-ancestor $SUB HEAD &&
+		test_must_fail git merge-base --is-ancestor $SPLIT HEAD &&
+		git rev-list HEAD ^$MAIN >commit-list &&
+		test_line_count = 2 commit-list &&
+		test "$(git rev-parse --verify HEAD:)"           = "$(git rev-parse --verify $MAIN:)" &&
+		test "$(git rev-parse --verify HEAD:"sub dir")"  = "$(git rev-parse --verify $SPLIT:)" &&
+		test "$(git rev-parse --verify HEAD^1)"          = $MAIN &&
+		test "$(git rev-parse --verify HEAD^2)"         != $SPLIT &&
+		test "$(git rev-parse --verify HEAD^2:)"         = "$(git rev-parse --verify $SPLIT:)" &&
+		test "$(last_commit_subject)" = "Split '\''sub dir/'\'' into commit '\''$SPLIT'\''" &&
+		test "$SPLIT" = "$(git -C "sub proj" rev-parse --verify refs/heads/from-mainline)"
+	)
+'
+
+test_expect_success 'push "sub dir"/ with --branch' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		git subtree push --prefix="sub dir" --annotate="*" --branch subproj-br ./"sub proj" from-mainline &&
+		test "$(git rev-parse subproj-br)" = "$split_hash" &&
+		test "$split_hash" = "$(git -C "sub proj" rev-parse --verify refs/heads/from-mainline)"
+	)
+'
+
+test_expect_success 'check hash of push' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		git subtree push --prefix="sub dir" --annotate="*" --branch subproj-br ./"sub proj" from-mainline &&
+		test "$(git rev-parse subproj-br)" = "$split_hash" &&
+		# Check hash of split
+		new_hash=$(git rev-parse subproj-br^2) &&
+		(
+			cd ./"sub proj" &&
+			subdir_hash=$(git rev-parse HEAD) &&
+			test "$new_hash" = "$subdir_hash"
+		) &&
+		test "$split_hash" = "$(git -C "sub proj" rev-parse --verify refs/heads/from-mainline)"
+	)
+'
+
+test_expect_success 'push "sub dir"/ with --branch for an existing branch' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git branch subproj-br FETCH_HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		git subtree push --prefix="sub dir" --annotate="*" --branch subproj-br ./"sub proj" from-mainline &&
+		test "$(git rev-parse subproj-br)" = "$split_hash" &&
+		test "$split_hash" = "$(git -C "sub proj" rev-parse --verify refs/heads/from-mainline)"
+	)
+'
+
+test_expect_success 'push "sub dir"/ with --branch for an incompatible branch' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git branch init HEAD &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		test_must_fail git subtree push --prefix="sub dir" --branch init "./sub proj" from-mainline
+	)
+'
+
+test_expect_success 'push "sub dir"/ with a local rev' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		bad_tree=$(git rev-parse --verify HEAD:"sub dir") &&
+		good_tree=$(git rev-parse --verify HEAD^:"sub dir") &&
+		git subtree push --prefix="sub dir" --annotate="*" ./"sub proj" HEAD^:from-mainline &&
+		split_tree=$(git -C "sub proj" rev-parse --verify refs/heads/from-mainline:) &&
+		test "$split_tree" = "$good_tree"
+	)
+'
+
+test_expect_success 'push after annotated tag was added/merged with --squash pre-v2.32.0' '
+	test_create_pre2_32_repo "$test_count" &&
+	test_create_commit "$test_count-clone" sub/main-sub1 &&
+	git -C "$test_count-clone" subtree push --prefix="sub" "../$test_count-sub" from-mainline
+'
+
+#
+# Validity checking
+#
+
+test_expect_success 'make sure exactly the right set of files ends up in the subproj' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count/sub proj" sub3 &&
+	test_create_commit "$test_count" "sub dir"/main-sub3 &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD &&
+
+		test_write_lines main-sub1 main-sub2 main-sub3 main-sub4 \
+			sub1 sub2 sub3 sub4 >expect &&
+		git ls-files >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'make sure the subproj *only* contains commits that affect the "sub dir"' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count/sub proj" sub3 &&
+	test_create_commit "$test_count" "sub dir"/main-sub3 &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD &&
+
+		test_write_lines main-sub1 main-sub2 main-sub3 main-sub4 \
+			sub1 sub2 sub3 sub4 >expect &&
+		git log --name-only --pretty=format:"" >log &&
+		sort <log | sed "/^\$/ d" >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'make sure exactly the right set of files ends up in the mainline' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count/sub proj" sub3 &&
+	test_create_commit "$test_count" "sub dir"/main-sub3 &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD
+	) &&
+	(
+		cd "$test_count" &&
+		git subtree pull --prefix="sub dir" ./"sub proj" HEAD &&
+
+		test_write_lines main1 main2 >chkm &&
+		test_write_lines main-sub1 main-sub2 main-sub3 main-sub4 >chkms &&
+		sed "s,^,sub dir/," chkms >chkms_sub &&
+		test_write_lines sub1 sub2 sub3 sub4 >chks &&
+		sed "s,^,sub dir/," chks >chks_sub &&
+
+		cat chkm chkms_sub chks_sub >expect &&
+		git ls-files >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'make sure each filename changed exactly once in the entire history' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git config log.date relative &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count/sub proj" sub3 &&
+	test_create_commit "$test_count" "sub dir"/main-sub3 &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD
+	) &&
+	(
+		cd "$test_count" &&
+		git subtree pull --prefix="sub dir" ./"sub proj" HEAD &&
+
+		test_write_lines main1 main2 >chkm &&
+		test_write_lines sub1 sub2 sub3 sub4 >chks &&
+		test_write_lines main-sub1 main-sub2 main-sub3 main-sub4 >chkms &&
+		sed "s,^,sub dir/," chkms >chkms_sub &&
+
+		# main-sub?? and /"sub dir"/main-sub?? both change, because those are the
+		# changes that were split into their own history.  And "sub dir"/sub?? never
+		# change, since they were *only* changed in the subtree branch.
+		git log --name-only --pretty=format:"" >log &&
+		sort <log >sorted-log &&
+		sed "/^$/ d" sorted-log >actual &&
+
+		cat chkms chkm chks chkms_sub >expect-unsorted &&
+		sort expect-unsorted >expect &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'make sure the --rejoin commits never make it into subproj' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count/sub proj" sub3 &&
+	test_create_commit "$test_count" "sub dir"/main-sub3 &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD
+	) &&
+	(
+		cd "$test_count" &&
+		git subtree pull --prefix="sub dir" ./"sub proj" HEAD &&
+		test "$(git log --pretty=format:"%s" HEAD^2 | grep -i split)" = ""
+	)
+'
+
+test_expect_success 'make sure no "git subtree" tagged commits make it into subproj' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count/sub proj" sub3 &&
+	test_create_commit "$test_count" "sub dir"/main-sub3 &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		 git merge FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub4 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --annotate="*" --branch subproj-br --rejoin
+	) &&
+	(
+		cd "$test_count/sub proj" &&
+		git fetch .. subproj-br &&
+		git merge FETCH_HEAD
+	) &&
+	(
+		cd "$test_count" &&
+		git subtree pull --prefix="sub dir" ./"sub proj" HEAD &&
+
+		# They are meaningless to subproj since one side of the merge refers to the mainline
+		test "$(git log --pretty=format:"%s%n%b" HEAD^2 | grep "git-subtree.*:")" = ""
+	)
+'
+
+#
+# A new set of tests
+#
+
+test_expect_success 'make sure "git subtree split" find the correct parent' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git branch subproj-ref FETCH_HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --branch subproj-br &&
+
+		# at this point, the new commit parent should be subproj-ref, if it is
+		# not, something went wrong (the "newparent" of "HEAD~" commit should
+		# have been sub2, but it was not, because its cache was not set to
+		# itself)
+		test "$(git log --pretty=format:%P -1 subproj-br)" = "$(git rev-parse subproj-ref)"
+	)
+'
+
+test_expect_success 'split a new subtree without --onto option' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --branch subproj-br
+	) &&
+	mkdir "$test_count"/"sub dir2" &&
+	test_create_commit "$test_count" "sub dir2"/main-sub2 &&
+	(
+		cd "$test_count" &&
+
+		# also test that we still can split out an entirely new subtree
+		# if the parent of the first commit in the tree is not empty,
+		# then the new subtree has accidentally been attached to something
+		git subtree split --prefix="sub dir2" --branch subproj2-br &&
+		test "$(git log --pretty=format:%P -1 subproj2-br)" = ""
+	)
+'
+
+test_expect_success 'verify one file change per commit' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git branch sub1 FETCH_HEAD &&
+		git subtree add --prefix="sub dir" sub1
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir" --branch subproj-br
+	) &&
+	mkdir "$test_count"/"sub dir2" &&
+	test_create_commit "$test_count" "sub dir2"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git subtree split --prefix="sub dir2" --branch subproj2-br &&
+
+		git log --format="%H" >commit-list &&
+		while read commit
+		do
+			git log -n1 --format="" --name-only "$commit" >file-list &&
+			test_line_count -le 1 file-list || return 1
+		done <commit-list
+	)
+'
+
+test_expect_success 'push split to subproj' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd $test_count/"sub proj" &&
+		git branch sub-branch-1 &&
+		cd .. &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub3 &&
+	(
+		cd "$test_count" &&
+		git subtree push ./"sub proj" --prefix "sub dir" sub-branch-1 &&
+		cd ./"sub proj" &&
+		git checkout sub-branch-1 &&
+		test "$(last_commit_subject)" = "sub dir/main-sub3"
+	)
+'
+
+#
+# This test covers 2 cases in subtree split copy_or_skip code
+# 1) Merges where one parent is a superset of the changes of the other
+#    parent regarding changes to the subtree, in this case the merge
+#    commit should be copied
+# 2) Merges where only one parent operate on the subtree, and the merge
+#    commit should be skipped
+#
+# (1) is checked by ensuring subtree_tip is a descendent of subtree_branch
+# (2) should have a check added (not_a_subtree_change shouldn't be present
+#     on the produced subtree)
+#
+# Other related cases which are not tested (or currently handled correctly)
+# - Case (1) where there are more than 2 parents, it will sometimes correctly copy
+#   the merge, and sometimes not
+# - Merge commit where both parents have same tree as the merge, currently
+#   will always be skipped, even if they reached that state via different
+#   set of commits.
+#
+
+test_expect_success 'subtree descendant check' '
+	subtree_test_create_repo "$test_count" &&
+	defaultBranch=$(sed "s,ref: refs/heads/,," "$test_count/.git/HEAD") &&
+	test_create_commit "$test_count" folder_subtree/a &&
+	(
+		cd "$test_count" &&
+		git branch branch
+	) &&
+	test_create_commit "$test_count" folder_subtree/0 &&
+	test_create_commit "$test_count" folder_subtree/b &&
+	cherry=$(cd "$test_count" && git rev-parse HEAD) &&
+	(
+		cd "$test_count" &&
+		git checkout branch
+	) &&
+	test_create_commit "$test_count" commit_on_branch &&
+	(
+		cd "$test_count" &&
+		git cherry-pick $cherry &&
+		git checkout $defaultBranch &&
+		git merge -m "merge should be kept on subtree" branch &&
+		git branch no_subtree_work_branch
+	) &&
+	test_create_commit "$test_count" folder_subtree/d &&
+	(
+		cd "$test_count" &&
+		git checkout no_subtree_work_branch
+	) &&
+	test_create_commit "$test_count" not_a_subtree_change &&
+	(
+		cd "$test_count" &&
+		git checkout $defaultBranch &&
+		git merge -m "merge should be skipped on subtree" no_subtree_work_branch &&
+
+		git subtree split --prefix folder_subtree/ --branch subtree_tip $defaultBranch &&
+		git subtree split --prefix folder_subtree/ --branch subtree_branch branch &&
+		test $(git rev-list --count subtree_tip..subtree_branch) = 0
+	)
+'
+
+test_done
diff --git a/contrib/subtree/todo b/contrib/subtree/todo
new file mode 100644
index 0000000..32d2ce3
--- /dev/null
+++ b/contrib/subtree/todo
@@ -0,0 +1,48 @@
+
+	delete tempdir
+
+	'git subtree rejoin' option to do the same as --rejoin, eg. after a
+	  rebase
+
+	--prefix doesn't force the subtree correctly in merge/pull:
+	"-s subtree" should be given an explicit subtree option?
+		There doesn't seem to be a way to do this.  We'd have to
+		patch git-merge-subtree.  Ugh.
+		(but we could avoid this problem by generating squashes with
+		exactly the right subtree structure, rather than using
+		subtree merge...)
+
+	add a 'log' subcommand to see what's new in a subtree?
+
+	add to-submodule and from-submodule commands
+
+	automated tests for --squash stuff
+
+	"add" command non-obviously requires a commitid; would be easier if
+		it had a "pull" sort of mode instead
+
+	"pull" and "merge" commands should fail if you've never merged
+		that --prefix before
+
+	docs should provide an example of "add"
+
+	note that the initial split doesn't *have* to have a commitid
+		specified... that's just an optimization
+
+	if you try to add (or maybe merge?) with an invalid commitid, you
+		get a misleading "prefix must end with /" message from
+		one of the other git tools that git-subtree calls.  Should
+		detect this situation and print the *real* problem.
+
+	"pull --squash" should do fetch-synthesize-merge, but instead just
+		does "pull" directly, which doesn't work at all.
+
+	make a 'force-update' that does what 'add' does even if the subtree
+		already exists.  That way we can help people who imported
+		subtrees "incorrectly" (eg. by just copying in the files) in
+		the past.
+
+	guess --prefix automatically if possible based on pwd
+
+	make a 'git subtree grafts' that automatically expands --squash'd
+		commits so you can see the full history if you want it.