From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 13 Feb 2018 21:39:03 +0000 (-0800)
Subject: Merge branch 'jh/fsck-promisors'
X-Git-Tag: v2.17.0-rc0~133
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/f3d618d2bf4099abe99babc8b56dcd483c5eec71?hp=-c

Merge branch 'jh/fsck-promisors'

In preparation for implementing narrow/partial clone, the machinery
for checking object connectivity used by gc and fsck has been
taught that a missing object is OK when it is referenced by a
packfile specially marked as coming from trusted repository that
promises to make them available on-demand and lazily.

* jh/fsck-promisors:
gc: do not repack promisor packfiles
rev-list: support termination at promisor objects
sha1_file: support lazily fetching missing objects
introduce fetch-object: fetch one promisor object
index-pack: refactor writing of .keep files
fsck: support promisor objects as CLI argument
fsck: support referenced promisor objects
fsck: support refs pointing to promisor objects
fsck: introduce partialclone extension
extension.partialclone: introduce partial clone extension
---

f3d618d2bf4099abe99babc8b56dcd483c5eec71
diff --combined Documentation/rev-list-options.txt
index 22f5c9b43d,0ce8ccdd43..7b273635de
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@@ -686,11 -686,6 +686,11 @@@ ifdef::git-rev-list[
  	all object IDs which I need to download if I have the commit
  	object _bar_ but not _foo_''.
  
 +--in-commit-order::
 +	Print tree and blob ids in order of the commits. The tree
 +	and blob ids are printed after they are first referenced
 +	by a commit.
 +
  --objects-edge::
  	Similar to `--objects`, but also print the IDs of excluded
  	commits prefixed with a ``-'' character.  This is used by
@@@ -750,10 -745,21 +750,21 @@@ The form '--missing=allow-any' will all
  if a missing object is encountered.  Missing objects will silently be
  omitted from the results.
  +
+ The form '--missing=allow-promisor' is like 'allow-any', but will only
+ allow object traversal to continue for EXPECTED promisor missing objects.
+ Unexpected missing objects will raise an error.
+ +
  The form '--missing=print' is like 'allow-any', but will also print a
  list of the missing objects.  Object IDs are prefixed with a ``?'' character.
  endif::git-rev-list[]
  
+ --exclude-promisor-objects::
+ 	(For internal use only.)  Prefilter object traversal at
+ 	promisor boundary.  This is used with partial clone.  This is
+ 	stronger than `--missing=allow-promisor` because it limits the
+ 	traversal, rather than just silencing errors about missing
+ 	objects.
+ 
  --no-walk[=(sorted|unsorted)]::
  	Only show the given commits, but do not traverse their ancestors.
  	This has no effect if a range is specified. If the argument
diff --combined Makefile
index 37e02cec1b,795e0c7cb5..eb74e6cf3c
--- a/Makefile
+++ b/Makefile
@@@ -23,6 -23,7 +23,6 @@@ all:
  # it at all).
  #
  # Define NO_OPENSSL environment variable if you do not have OpenSSL.
 -# This also implies BLK_SHA1.
  #
  # Define USE_LIBPCRE if you have and want to use libpcre. Various
  # commands such as log and grep offer runtime options to use
@@@ -294,6 -295,9 +294,6 @@@
  #
  # Define PERL_PATH to the path of your Perl binary (usually /usr/bin/perl).
  #
 -# Define NO_PERL_MAKEMAKER if you cannot use Makefiles generated by perl's
 -# MakeMaker (e.g. using ActiveState under Cygwin).
 -#
  # Define NO_PERL if you do not want Perl scripts or libraries at all.
  #
  # Define PYTHON_PATH to the path of your Python binary (often /usr/bin/python
@@@ -421,13 -425,6 +421,13 @@@
  #
  # to say "export LESS=FRX (and LV=-c) if the environment variable
  # LESS (and LV) is not set, respectively".
 +#
 +# Define TEST_SHELL_PATH if you want to use a shell besides SHELL_PATH for
 +# running the test scripts (e.g., bash has better support for "set -x"
 +# tracing).
 +#
 +# When cross-compiling, define HOST_CPU as the canonical name of the CPU on
 +# which the built Git will run (for instance "x86_64").
  
  GIT-VERSION-FILE: FORCE
  	@$(SHELL_PATH) ./GIT-VERSION-GEN
@@@ -476,7 -473,6 +476,7 @@@ gitexecdir = libexec/git-cor
  mergetoolsdir = $(gitexecdir)/mergetools
  sharedir = $(prefix)/share
  gitwebdir = $(sharedir)/gitweb
 +perllibdir = $(sharedir)/perl5
  localedir = $(sharedir)/locale
  template_dir = share/git-core/templates
  htmldir = $(prefix)/share/doc/git-doc
@@@ -490,7 -486,7 +490,7 @@@ mandir_relative = $(patsubst $(prefix)/
  infodir_relative = $(patsubst $(prefix)/%,%,$(infodir))
  htmldir_relative = $(patsubst $(prefix)/%,%,$(htmldir))
  
 -export prefix bindir sharedir sysconfdir gitwebdir localedir
 +export prefix bindir sharedir sysconfdir gitwebdir perllibdir localedir
  
  CC = cc
  AR = ar
@@@ -650,12 -646,9 +650,12 @@@ TEST_PROGRAMS_NEED_X += test-ctyp
  TEST_PROGRAMS_NEED_X += test-config
  TEST_PROGRAMS_NEED_X += test-date
  TEST_PROGRAMS_NEED_X += test-delta
 +TEST_PROGRAMS_NEED_X += test-drop-caches
  TEST_PROGRAMS_NEED_X += test-dump-cache-tree
 +TEST_PROGRAMS_NEED_X += test-dump-fsmonitor
  TEST_PROGRAMS_NEED_X += test-dump-split-index
  TEST_PROGRAMS_NEED_X += test-dump-untracked-cache
 +TEST_PROGRAMS_NEED_X += test-example-decorate
  TEST_PROGRAMS_NEED_X += test-fake-ssh
  TEST_PROGRAMS_NEED_X += test-genrandom
  TEST_PROGRAMS_NEED_X += test-hashmap
@@@ -734,8 -727,6 +734,8 @@@ endi
  export PERL_PATH
  export PYTHON_PATH
  
 +TEST_SHELL_PATH = $(SHELL_PATH)
 +
  LIB_FILE = libgit.a
  XDIFF_LIB = xdiff/lib.a
  VCSSVN_LIB = vcs-svn/lib.a
@@@ -766,7 -757,6 +766,7 @@@ LIB_OBJS += branch.
  LIB_OBJS += bulk-checkin.o
  LIB_OBJS += bundle.o
  LIB_OBJS += cache-tree.o
 +LIB_OBJS += checkout.o
  LIB_OBJS += color.o
  LIB_OBJS += column.o
  LIB_OBJS += combine-diff.o
@@@ -802,9 -792,9 +802,10 @@@ LIB_OBJS += ewah/ewah_bitmap.
  LIB_OBJS += ewah/ewah_io.o
  LIB_OBJS += ewah/ewah_rlw.o
  LIB_OBJS += exec_cmd.o
+ LIB_OBJS += fetch-object.o
  LIB_OBJS += fetch-pack.o
  LIB_OBJS += fsck.o
 +LIB_OBJS += fsmonitor.o
  LIB_OBJS += gettext.o
  LIB_OBJS += gpg-interface.o
  LIB_OBJS += graph.o
@@@ -859,7 -849,6 +860,7 @@@ LIB_OBJS += pretty.
  LIB_OBJS += prio-queue.o
  LIB_OBJS += progress.o
  LIB_OBJS += prompt.o
 +LIB_OBJS += protocol.o
  LIB_OBJS += quote.o
  LIB_OBJS += reachable.o
  LIB_OBJS += read-cache.o
@@@ -1105,12 -1094,6 +1106,12 @@@ els
  BROKEN_PATH_FIX = '/^\# @@BROKEN_PATH_FIX@@$$/d'
  endif
  
 +ifeq (,$(HOST_CPU))
 +	BASIC_CFLAGS += -DGIT_HOST_CPU="\"$(firstword $(subst -, ,$(uname_M)))\""
 +else
 +	BASIC_CFLAGS += -DGIT_HOST_CPU="\"$(HOST_CPU)\""
 +endif
 +
  ifneq (,$(INLINE))
  	BASIC_CFLAGS += -Dinline=$(INLINE)
  endif
@@@ -1272,6 -1255,7 +1273,6 @@@ ifndef NO_OPENSS
  	endif
  else
  	BASIC_CFLAGS += -DNO_OPENSSL
 -	BLK_SHA1 = 1
  	OPENSSL_LIBSSL =
  endif
  ifdef NO_OPENSSL
@@@ -1541,6 -1525,9 +1542,6 @@@ ifdef SHA1_MAX_BLOCK_SIZ
  	LIB_OBJS += compat/sha1-chunked.o
  	BASIC_CFLAGS += -DSHA1_MAX_BLOCK_SIZE="$(SHA1_MAX_BLOCK_SIZE)"
  endif
 -ifdef NO_PERL_MAKEMAKER
 -	export NO_PERL_MAKEMAKER
 -endif
  ifdef NO_HSTRERROR
  	COMPAT_CFLAGS += -DNO_HSTRERROR
  	COMPAT_OBJS += compat/hstrerror.o
@@@ -1727,10 -1714,8 +1728,10 @@@ ETC_GITATTRIBUTES_SQ = $(subst ','\'',$
  DESTDIR_SQ = $(subst ','\'',$(DESTDIR))
  bindir_SQ = $(subst ','\'',$(bindir))
  bindir_relative_SQ = $(subst ','\'',$(bindir_relative))
 +mandir_SQ = $(subst ','\'',$(mandir))
  mandir_relative_SQ = $(subst ','\'',$(mandir_relative))
  infodir_relative_SQ = $(subst ','\'',$(infodir_relative))
 +perllibdir_SQ = $(subst ','\'',$(perllibdir))
  localedir_SQ = $(subst ','\'',$(localedir))
  gitexecdir_SQ = $(subst ','\'',$(gitexecdir))
  template_dir_SQ = $(subst ','\'',$(template_dir))
@@@ -1739,7 -1724,6 +1740,7 @@@ prefix_SQ = $(subst ','\'',$(prefix)
  gitwebdir_SQ = $(subst ','\'',$(gitwebdir))
  
  SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
 +TEST_SHELL_PATH_SQ = $(subst ','\'',$(TEST_SHELL_PATH))
  PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
  PYTHON_PATH_SQ = $(subst ','\'',$(PYTHON_PATH))
  TCLTK_PATH_SQ = $(subst ','\'',$(TCLTK_PATH))
@@@ -1840,6 -1824,9 +1841,6 @@@ all:
  ifndef NO_TCLTK
  	$(QUIET_SUBDIR0)git-gui $(QUIET_SUBDIR1) gitexecdir='$(gitexec_instdir_SQ)' all
  	$(QUIET_SUBDIR0)gitk-git $(QUIET_SUBDIR1) all
 -endif
 -ifndef NO_PERL
 -	$(QUIET_SUBDIR0)perl $(QUIET_SUBDIR1) PERL_PATH='$(PERL_PATH_SQ)' prefix='$(prefix_SQ)' localedir='$(localedir_SQ)' all
  endif
  	$(QUIET_SUBDIR0)templates $(QUIET_SUBDIR1) SHELL_PATH='$(SHELL_PATH_SQ)' PERL_PATH='$(PERL_PATH_SQ)'
  
@@@ -1905,9 -1892,7 +1906,9 @@@ builtin/help.sp builtin/help.s builtin/
  version.sp version.s version.o: GIT-VERSION-FILE GIT-USER-AGENT
  version.sp version.s version.o: EXTRA_CPPFLAGS = \
  	'-DGIT_VERSION="$(GIT_VERSION)"' \
 -	'-DGIT_USER_AGENT=$(GIT_USER_AGENT_CQ_SQ)'
 +	'-DGIT_USER_AGENT=$(GIT_USER_AGENT_CQ_SQ)' \
 +	'-DGIT_BUILT_FROM_COMMIT="$(shell GIT_CEILING_DIRECTORIES=\"$(CURDIR)/..\" \
 +		git rev-parse -q --verify HEAD || :)"'
  
  $(BUILT_INS): git$X
  	$(QUIET_BUILT_IN)$(RM) $@ && \
@@@ -1922,8 -1907,7 +1923,8 @@@ common-cmds.h: $(wildcard Documentation
  
  SCRIPT_DEFINES = $(SHELL_PATH_SQ):$(DIFF_SQ):$(GIT_VERSION):\
  	$(localedir_SQ):$(NO_CURL):$(USE_GETTEXT_SCHEME):$(SANE_TOOL_PATH_SQ):\
 -	$(gitwebdir_SQ):$(PERL_PATH_SQ):$(SANE_TEXT_GREP):$(PAGER_ENV)
 +	$(gitwebdir_SQ):$(PERL_PATH_SQ):$(SANE_TEXT_GREP):$(PAGER_ENV):\
 +	$(perllibdir_SQ)
  define cmd_munge_script
  $(RM) $@ $@+ && \
  sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
@@@ -1959,20 -1943,30 +1960,20 @@@ $(SCRIPT_LIB) : % : %.sh GIT-SCRIPT-DEF
  
  git.res: git.rc GIT-VERSION-FILE
  	$(QUIET_RC)$(RC) \
 -	  $(join -DMAJOR= -DMINOR=, $(wordlist 1,2,$(subst -, ,$(subst ., ,$(GIT_VERSION))))) \
 +	  $(join -DMAJOR= -DMINOR= -DMICRO= -DPATCHLEVEL=, $(wordlist 1, 4, \
 +	    $(shell echo $(GIT_VERSION) 0 0 0 0 | tr '.a-zA-Z-' ' '))) \
  	  -DGIT_VERSION="\\\"$(GIT_VERSION)\\\"" -i $< -o $@
  
  # This makes sure we depend on the NO_PERL setting itself.
  $(SCRIPT_PERL_GEN): GIT-BUILD-OPTIONS
  
  ifndef NO_PERL
 -$(SCRIPT_PERL_GEN): perl/perl.mak
 +$(SCRIPT_PERL_GEN):
  
 -perl/perl.mak: perl/PM.stamp
 -
 -perl/PM.stamp: FORCE
 -	@$(FIND) perl -type f -name '*.pm' | sort >$@+ && \
 -	$(PERL_PATH) -V >>$@+ && \
 -	{ cmp $@+ $@ >/dev/null 2>/dev/null || mv $@+ $@; } && \
 -	$(RM) $@+
 -
 -perl/perl.mak: GIT-CFLAGS GIT-PREFIX perl/Makefile perl/Makefile.PL
 -	$(QUIET_SUBDIR0)perl $(QUIET_SUBDIR1) PERL_PATH='$(PERL_PATH_SQ)' prefix='$(prefix_SQ)' $(@F)
 -
 -PERL_DEFINES = $(PERL_PATH_SQ):$(PERLLIB_EXTRA_SQ)
 -$(SCRIPT_PERL_GEN): % : %.perl perl/perl.mak GIT-PERL-DEFINES GIT-VERSION-FILE
 +PERL_DEFINES = $(PERL_PATH_SQ):$(PERLLIB_EXTRA_SQ):$(perllibdir_SQ)
 +$(SCRIPT_PERL_GEN): % : %.perl GIT-PERL-DEFINES GIT-VERSION-FILE
  	$(QUIET_GEN)$(RM) $@ $@+ && \
 -	INSTLIBDIR=`MAKEFLAGS= $(MAKE) -C perl -s --no-print-directory instlibdir` && \
 +	INSTLIBDIR='$(perllibdir_SQ)' && \
  	INSTLIBDIR_EXTRA='$(PERLLIB_EXTRA_SQ)' && \
  	INSTLIBDIR="$$INSTLIBDIR$${INSTLIBDIR_EXTRA:+:$$INSTLIBDIR_EXTRA}" && \
  	sed -e '1{' \
@@@ -2296,21 -2290,6 +2297,21 @@@ endi
  po/build/locale/%/LC_MESSAGES/git.mo: po/%.po
  	$(QUIET_MSGFMT)mkdir -p $(dir $@) && $(MSGFMT) -o $@ $<
  
 +LIB_PERL := $(wildcard perl/Git.pm perl/Git/*.pm perl/Git/*/*.pm perl/Git/*/*/*.pm)
 +LIB_PERL_GEN := $(patsubst perl/%.pm,perl/build/lib/%.pm,$(LIB_PERL))
 +
 +ifndef NO_PERL
 +all:: $(LIB_PERL_GEN)
 +endif
 +
 +perl/build/lib/%.pm: perl/%.pm
 +	$(QUIET_GEN)mkdir -p $(dir $@) && \
 +	sed -e 's|@@LOCALEDIR@@|$(localedir_SQ)|g' < $< > $@
 +
 +perl/build/man/man3/Git.3pm: perl/Git.pm
 +	$(QUIET_GEN)mkdir -p $(dir $@) && \
 +	pod2man $< $@
 +
  FIND_SOURCE_FILES = ( \
  	git ls-files \
  		'*.[hcS]' \
@@@ -2374,7 -2353,6 +2375,7 @@@ GIT-LDFLAGS: FORC
  # and the first level quoting from the shell that runs "echo".
  GIT-BUILD-OPTIONS: FORCE
  	@echo SHELL_PATH=\''$(subst ','\'',$(SHELL_PATH_SQ))'\' >$@+
 +	@echo TEST_SHELL_PATH=\''$(subst ','\'',$(TEST_SHELL_PATH_SQ))'\' >>$@+
  	@echo PERL_PATH=\''$(subst ','\'',$(PERL_PATH_SQ))'\' >>$@+
  	@echo DIFF=\''$(subst ','\'',$(subst ','\'',$(DIFF)))'\' >>$@+
  	@echo PYTHON_PATH=\''$(subst ','\'',$(PYTHON_PATH_SQ))'\' >>$@+
@@@ -2571,9 -2549,7 +2572,9 @@@ ifndef NO_GETTEX
  	(cd '$(DESTDIR_SQ)$(localedir_SQ)' && umask 022 && $(TAR) xof -)
  endif
  ifndef NO_PERL
 -	$(MAKE) -C perl prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' install
 +	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perllibdir_SQ)'
 +	(cd perl/build/lib && $(TAR) cf - .) | \
 +	(cd '$(DESTDIR_SQ)$(perllibdir_SQ)' && umask 022 && $(TAR) xof -)
  	$(MAKE) -C gitweb install
  endif
  ifndef NO_TCLTK
@@@ -2623,17 -2599,12 +2624,17 @@@ endi
  install-gitweb:
  	$(MAKE) -C gitweb install
  
 -install-doc:
 +install-doc: install-man-perl
  	$(MAKE) -C Documentation install
  
 -install-man:
 +install-man: install-man-perl
  	$(MAKE) -C Documentation install-man
  
 +install-man-perl: perl/build/man/man3/Git.3pm
 +	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(mandir_SQ)/man3'
 +	(cd perl/build/man/man3 && $(TAR) cf - .) | \
 +	(cd '$(DESTDIR_SQ)$(mandir_SQ)/man3' && umask 022 && $(TAR) xof -)
 +
  install-html:
  	$(MAKE) -C Documentation install-html
  
@@@ -2725,7 -2696,7 +2726,7 @@@ clean: profile-clean coverage-clea
  	$(MAKE) -C Documentation/ clean
  ifndef NO_PERL
  	$(MAKE) -C gitweb clean
 -	$(MAKE) -C perl clean
 +	$(RM) -r perl/build/
  endif
  	$(MAKE) -C templates/ clean
  	$(MAKE) -C t/ clean
diff --combined builtin/fsck.c
index 04846d46f9,3b76c0ef0f..7a8a679d4f
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@@ -149,6 -149,15 +149,15 @@@ static int mark_object(struct object *o
  	if (obj->flags & REACHABLE)
  		return 0;
  	obj->flags |= REACHABLE;
+ 
+ 	if (is_promisor_object(&obj->oid))
+ 		/*
+ 		 * Further recursion does not need to be performed on this
+ 		 * object since it is a promisor object (so it does not need to
+ 		 * be added to "pending").
+ 		 */
+ 		return 0;
+ 
  	if (!(obj->flags & HAS_OBJ)) {
  		if (parent && !has_object_file(&obj->oid)) {
  			printf("broken link from %7s %s\n",
@@@ -208,6 -217,8 +217,8 @@@ static void check_reachable_object(stru
  	 * do a full fsck
  	 */
  	if (!(obj->flags & HAS_OBJ)) {
+ 		if (is_promisor_object(&obj->oid))
+ 			return;
  		if (has_sha1_pack(obj->oid.hash))
  			return; /* it is in pack - forget about it */
  		printf("missing %s %s\n", printable_type(obj),
@@@ -398,7 -409,7 +409,7 @@@ static void fsck_handle_reflog_oid(cons
  					xstrfmt("%s@{%"PRItime"}", refname, timestamp));
  			obj->flags |= USED;
  			mark_object_reachable(obj);
- 		} else {
+ 		} else if (!is_promisor_object(oid)) {
  			error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
  			errors_found |= ERROR_REACHABLE;
  		}
@@@ -434,6 -445,14 +445,14 @@@ static int fsck_handle_ref(const char *
  
  	obj = parse_object(oid);
  	if (!obj) {
+ 		if (is_promisor_object(oid)) {
+ 			/*
+ 			 * Increment default_refs anyway, because this is a
+ 			 * valid ref.
+ 			 */
+ 			 default_refs++;
+ 			 return 0;
+ 		}
  		error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
  		errors_found |= ERROR_REACHABLE;
  		/* We'll continue with the rest despite the error.. */
@@@ -555,7 -574,7 +574,7 @@@ static int fsck_head_link(void
  	if (verbose)
  		fprintf(stderr, "Checking HEAD link\n");
  
 -	head_points_at = resolve_ref_unsafe("HEAD", 0, head_oid.hash, NULL);
 +	head_points_at = resolve_ref_unsafe("HEAD", 0, &head_oid, NULL);
  	if (!head_points_at) {
  		errors_found |= ERROR_REFS;
  		return error("Invalid HEAD");
@@@ -659,6 -678,9 +678,9 @@@ int cmd_fsck(int argc, const char **arg
  	int i;
  	struct alternate_object_database *alt;
  
+ 	/* fsck knows how to handle missing promisor objects */
+ 	fetch_if_missing = 0;
+ 
  	errors_found = 0;
  	check_replace_refs = 0;
  
@@@ -731,6 -753,8 +753,8 @@@
  			struct object *obj = lookup_object(oid.hash);
  
  			if (!obj || !(obj->flags & HAS_OBJ)) {
+ 				if (is_promisor_object(&oid))
+ 					continue;
  				error("%s: object missing", oid_to_hex(&oid));
  				errors_found |= ERROR_OBJECT;
  				continue;
@@@ -759,7 -783,6 +783,7 @@@
  
  	if (keep_cache_objects) {
  		verify_index_checksum = 1;
 +		verify_ce_order = 1;
  		read_cache();
  		for (i = 0; i < active_nr; i++) {
  			unsigned int mode;
diff --combined builtin/index-pack.c
index 4c51aec81f,a0a35e69c0..5ebd370c56
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@@ -1389,15 -1389,60 +1389,60 @@@ static void fix_unresolved_deltas(struc
  	free(sorted_by_pos);
  }
  
+ static const char *derive_filename(const char *pack_name, const char *suffix,
+ 				   struct strbuf *buf)
+ {
+ 	size_t len;
+ 	if (!strip_suffix(pack_name, ".pack", &len))
+ 		die(_("packfile name '%s' does not end with '.pack'"),
+ 		    pack_name);
+ 	strbuf_add(buf, pack_name, len);
+ 	strbuf_addch(buf, '.');
+ 	strbuf_addstr(buf, suffix);
+ 	return buf->buf;
+ }
+ 
+ static void write_special_file(const char *suffix, const char *msg,
+ 			       const char *pack_name, const unsigned char *sha1,
+ 			       const char **report)
+ {
+ 	struct strbuf name_buf = STRBUF_INIT;
+ 	const char *filename;
+ 	int fd;
+ 	int msg_len = strlen(msg);
+ 
+ 	if (pack_name)
+ 		filename = derive_filename(pack_name, suffix, &name_buf);
+ 	else
+ 		filename = odb_pack_name(&name_buf, sha1, suffix);
+ 
+ 	fd = odb_pack_keep(filename);
+ 	if (fd < 0) {
+ 		if (errno != EEXIST)
+ 			die_errno(_("cannot write %s file '%s'"),
+ 				  suffix, filename);
+ 	} else {
+ 		if (msg_len > 0) {
+ 			write_or_die(fd, msg, msg_len);
+ 			write_or_die(fd, "\n", 1);
+ 		}
+ 		if (close(fd) != 0)
+ 			die_errno(_("cannot close written %s file '%s'"),
+ 				  suffix, filename);
+ 		if (report)
+ 			*report = suffix;
+ 	}
+ 	strbuf_release(&name_buf);
+ }
+ 
  static void final(const char *final_pack_name, const char *curr_pack_name,
  		  const char *final_index_name, const char *curr_index_name,
- 		  const char *keep_name, const char *keep_msg,
+ 		  const char *keep_msg, const char *promisor_msg,
  		  unsigned char *sha1)
  {
  	const char *report = "pack";
  	struct strbuf pack_name = STRBUF_INIT;
  	struct strbuf index_name = STRBUF_INIT;
- 	struct strbuf keep_name_buf = STRBUF_INIT;
  	int err;
  
  	if (!from_stdin) {
@@@ -1409,28 -1454,12 +1454,12 @@@
  			die_errno(_("error while closing pack file"));
  	}
  
- 	if (keep_msg) {
- 		int keep_fd, keep_msg_len = strlen(keep_msg);
- 
- 		if (!keep_name)
- 			keep_name = odb_pack_name(&keep_name_buf, sha1, "keep");
- 
- 		keep_fd = odb_pack_keep(keep_name);
- 		if (keep_fd < 0) {
- 			if (errno != EEXIST)
- 				die_errno(_("cannot write keep file '%s'"),
- 					  keep_name);
- 		} else {
- 			if (keep_msg_len > 0) {
- 				write_or_die(keep_fd, keep_msg, keep_msg_len);
- 				write_or_die(keep_fd, "\n", 1);
- 			}
- 			if (close(keep_fd) != 0)
- 				die_errno(_("cannot close written keep file '%s'"),
- 					  keep_name);
- 			report = "keep";
- 		}
- 	}
+ 	if (keep_msg)
+ 		write_special_file("keep", keep_msg, final_pack_name, sha1,
+ 				   &report);
+ 	if (promisor_msg)
+ 		write_special_file("promisor", promisor_msg, final_pack_name,
+ 				   sha1, NULL);
  
  	if (final_pack_name != curr_pack_name) {
  		if (!final_pack_name)
@@@ -1472,7 -1501,6 +1501,6 @@@
  
  	strbuf_release(&index_name);
  	strbuf_release(&pack_name);
- 	strbuf_release(&keep_name_buf);
  }
  
  static int git_index_pack_config(const char *k, const char *v, void *cb)
@@@ -1615,32 -1643,26 +1643,26 @@@ static void show_pack_info(int stat_onl
  	}
  }
  
- static const char *derive_filename(const char *pack_name, const char *suffix,
- 				   struct strbuf *buf)
- {
- 	size_t len;
- 	if (!strip_suffix(pack_name, ".pack", &len))
- 		die(_("packfile name '%s' does not end with '.pack'"),
- 		    pack_name);
- 	strbuf_add(buf, pack_name, len);
- 	strbuf_addstr(buf, suffix);
- 	return buf->buf;
- }
- 
  int cmd_index_pack(int argc, const char **argv, const char *prefix)
  {
  	int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
  	const char *curr_index;
  	const char *index_name = NULL, *pack_name = NULL;
- 	const char *keep_name = NULL, *keep_msg = NULL;
- 	struct strbuf index_name_buf = STRBUF_INIT,
- 		      keep_name_buf = STRBUF_INIT;
+ 	const char *keep_msg = NULL;
+ 	const char *promisor_msg = NULL;
+ 	struct strbuf index_name_buf = STRBUF_INIT;
  	struct pack_idx_entry **idx_objects;
  	struct pack_idx_option opts;
  	unsigned char pack_sha1[20];
  	unsigned foreign_nr = 1;	/* zero is a "good" value, assume bad */
  	int report_end_of_input = 0;
  
+ 	/*
+ 	 * index-pack never needs to fetch missing objects, since it only
+ 	 * accesses the repo to do hash collision checks
+ 	 */
+ 	fetch_if_missing = 0;
+ 
  	if (argc == 2 && !strcmp(argv[1], "-h"))
  		usage(index_pack_usage);
  
@@@ -1660,7 -1682,10 +1682,7 @@@
  				from_stdin = 1;
  			} else if (!strcmp(arg, "--fix-thin")) {
  				fix_thin_pack = 1;
 -			} else if (!strcmp(arg, "--strict")) {
 -				strict = 1;
 -				do_fsck_object = 1;
 -			} else if (skip_prefix(arg, "--strict=", &arg)) {
 +			} else if (skip_to_optional_arg(arg, "--strict", &arg)) {
  				strict = 1;
  				do_fsck_object = 1;
  				fsck_set_msg_types(&fsck_options, arg);
@@@ -1676,8 -1701,14 +1698,10 @@@
  				verify = 1;
  				show_stat = 1;
  				stat_only = 1;
 -			} else if (!strcmp(arg, "--keep")) {
 -				keep_msg = "";
 -			} else if (starts_with(arg, "--keep=")) {
 -				keep_msg = arg + 7;
 -			} else if (!strcmp(arg, "--promisor")) {
 -				promisor_msg = "";
 -			} else if (starts_with(arg, "--promisor=")) {
 -				promisor_msg = arg + strlen("--promisor=");
 +			} else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
 +				; /* nothing to do */
++			} else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
++				; /* already parsed */
  			} else if (starts_with(arg, "--threads=")) {
  				char *end;
  				nr_threads = strtoul(arg+10, &end, 0);
@@@ -1740,9 -1771,7 +1764,7 @@@
  	if (from_stdin && !startup_info->have_repository)
  		die(_("--stdin requires a git repository"));
  	if (!index_name && pack_name)
- 		index_name = derive_filename(pack_name, ".idx", &index_name_buf);
- 	if (keep_msg && !keep_name && pack_name)
- 		keep_name = derive_filename(pack_name, ".keep", &keep_name_buf);
+ 		index_name = derive_filename(pack_name, "idx", &index_name_buf);
  
  	if (verify) {
  		if (!index_name)
@@@ -1790,13 -1819,12 +1812,12 @@@
  	if (!verify)
  		final(pack_name, curr_pack,
  		      index_name, curr_index,
- 		      keep_name, keep_msg,
+ 		      keep_msg, promisor_msg,
  		      pack_sha1);
  	else
  		close(input_fd);
  	free(objects);
  	strbuf_release(&index_name_buf);
- 	strbuf_release(&keep_name_buf);
  	if (pack_name == NULL)
  		free((void *) curr_pack);
  	if (index_name == NULL)
diff --combined builtin/pack-objects.c
index 6b9cfc289d,f5fc40177c..6c71552cdf
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@@ -75,6 -75,8 +75,8 @@@ static int use_bitmap_index = -1
  static int write_bitmap_index;
  static uint16_t write_bitmap_options;
  
+ static int exclude_promisor_objects;
+ 
  static unsigned long delta_cache_size = 0;
  static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
  static unsigned long cache_max_small_delta_size = 1000;
@@@ -84,8 -86,9 +86,9 @@@ static unsigned long window_memory_limi
  static struct list_objects_filter_options filter_options;
  
  enum missing_action {
- 	MA_ERROR = 0,    /* fail if any missing objects are encountered */
- 	MA_ALLOW_ANY,    /* silently allow ALL missing objects */
+ 	MA_ERROR = 0,      /* fail if any missing objects are encountered */
+ 	MA_ALLOW_ANY,      /* silently allow ALL missing objects */
+ 	MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
  };
  static enum missing_action arg_missing_action;
  static show_object_fn fn_show_object;
@@@ -162,7 -165,7 +165,7 @@@ static unsigned long do_compress(void *
  }
  
  static unsigned long write_large_blob_data(struct git_istream *st, struct sha1file *f,
 -					   const unsigned char *sha1)
 +					   const struct object_id *oid)
  {
  	git_zstream stream;
  	unsigned char ibuf[1024 * 16];
@@@ -176,7 -179,7 +179,7 @@@
  		int zret = Z_OK;
  		readlen = read_istream(st, ibuf, sizeof(ibuf));
  		if (readlen == -1)
 -			die(_("unable to read %s"), sha1_to_hex(sha1));
 +			die(_("unable to read %s"), oid_to_hex(oid));
  
  		stream.next_in = ibuf;
  		stream.avail_in = readlen;
@@@ -350,7 -353,7 +353,7 @@@ static unsigned long write_no_reuse_obj
  		sha1write(f, header, hdrlen);
  	}
  	if (st) {
 -		datalen = write_large_blob_data(st, f, entry->idx.oid.hash);
 +		datalen = write_large_blob_data(st, f, &entry->idx.oid);
  		close_istream(st);
  	} else {
  		sha1write(f, buf, datalen);
@@@ -568,13 -571,13 +571,13 @@@ static enum write_one_status write_one(
  static int mark_tagged(const char *path, const struct object_id *oid, int flag,
  		       void *cb_data)
  {
 -	unsigned char peeled[20];
 +	struct object_id peeled;
  	struct object_entry *entry = packlist_find(&to_pack, oid->hash, NULL);
  
  	if (entry)
  		entry->tagged = 1;
 -	if (!peel_ref(path, peeled)) {
 -		entry = packlist_find(&to_pack, peeled, NULL);
 +	if (!peel_ref(path, &peeled)) {
 +		entry = packlist_find(&to_pack, peeled.hash, NULL);
  		if (entry)
  			entry->tagged = 1;
  	}
@@@ -803,7 -806,7 +806,7 @@@ static void write_pack_file(void
  	write_order = compute_write_order();
  
  	do {
 -		unsigned char sha1[20];
 +		struct object_id oid;
  		char *pack_tmp_name = NULL;
  
  		if (pack_to_stdout)
@@@ -834,13 -837,13 +837,13 @@@
  		 * If so, rewrite it like in fast-import
  		 */
  		if (pack_to_stdout) {
 -			sha1close(f, sha1, CSUM_CLOSE);
 +			sha1close(f, oid.hash, CSUM_CLOSE);
  		} else if (nr_written == nr_remaining) {
 -			sha1close(f, sha1, CSUM_FSYNC);
 +			sha1close(f, oid.hash, CSUM_FSYNC);
  		} else {
 -			int fd = sha1close(f, sha1, 0);
 -			fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 -						 nr_written, sha1, offset);
 +			int fd = sha1close(f, oid.hash, 0);
 +			fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 +						 nr_written, oid.hash, offset);
  			close(fd);
  			if (write_bitmap_index) {
  				warning(_(no_split_warning));
@@@ -874,16 -877,16 +877,16 @@@
  			strbuf_addf(&tmpname, "%s-", base_name);
  
  			if (write_bitmap_index) {
 -				bitmap_writer_set_checksum(sha1);
 +				bitmap_writer_set_checksum(oid.hash);
  				bitmap_writer_build_type_index(written_list, nr_written);
  			}
  
  			finish_tmp_packfile(&tmpname, pack_tmp_name,
  					    written_list, nr_written,
 -					    &pack_idx_opts, sha1);
 +					    &pack_idx_opts, oid.hash);
  
  			if (write_bitmap_index) {
 -				strbuf_addf(&tmpname, "%s.bitmap", sha1_to_hex(sha1));
 +				strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
  
  				stop_progress(&progress_state);
  
@@@ -898,7 -901,7 +901,7 @@@
  
  			strbuf_release(&tmpname);
  			free(pack_tmp_name);
 -			puts(sha1_to_hex(sha1));
 +			puts(oid_to_hex(&oid));
  		}
  
  		/* mark written objects as written to previous pack */
@@@ -939,13 -942,13 +942,13 @@@ static int no_try_delta(const char *pat
   * found the item, since that saves us from having to look it up again a
   * few lines later when we want to add the new entry.
   */
 -static int have_duplicate_entry(const unsigned char *sha1,
 +static int have_duplicate_entry(const struct object_id *oid,
  				int exclude,
  				uint32_t *index_pos)
  {
  	struct object_entry *entry;
  
 -	entry = packlist_find(&to_pack, sha1, index_pos);
 +	entry = packlist_find(&to_pack, oid->hash, index_pos);
  	if (!entry)
  		return 0;
  
@@@ -1001,7 -1004,7 +1004,7 @@@ static int want_found_object(int exclud
   * function finds if there is any pack that has the object and returns the pack
   * and its offset in these variables.
   */
 -static int want_object_in_pack(const unsigned char *sha1,
 +static int want_object_in_pack(const struct object_id *oid,
  			       int exclude,
  			       struct packed_git **found_pack,
  			       off_t *found_offset)
@@@ -1009,7 -1012,7 +1012,7 @@@
  	struct mru_entry *entry;
  	int want;
  
 -	if (!exclude && local && has_loose_object_nonlocal(sha1))
 +	if (!exclude && local && has_loose_object_nonlocal(oid->hash))
  		return 0;
  
  	/*
@@@ -1030,7 -1033,7 +1033,7 @@@
  		if (p == *found_pack)
  			offset = *found_offset;
  		else
 -			offset = find_pack_entry_one(sha1, p);
 +			offset = find_pack_entry_one(oid->hash, p);
  
  		if (offset) {
  			if (!*found_pack) {
@@@ -1050,7 -1053,7 +1053,7 @@@
  	return 1;
  }
  
 -static void create_object_entry(const unsigned char *sha1,
 +static void create_object_entry(const struct object_id *oid,
  				enum object_type type,
  				uint32_t hash,
  				int exclude,
@@@ -1061,7 -1064,7 +1064,7 @@@
  {
  	struct object_entry *entry;
  
 -	entry = packlist_alloc(&to_pack, sha1, index_pos);
 +	entry = packlist_alloc(&to_pack, oid->hash, index_pos);
  	entry->hash = hash;
  	if (type)
  		entry->type = type;
@@@ -1081,17 -1084,17 +1084,17 @@@ static const char no_closure_warning[] 
  "disabling bitmap writing, as some objects are not being packed"
  );
  
 -static int add_object_entry(const unsigned char *sha1, enum object_type type,
 +static int add_object_entry(const struct object_id *oid, enum object_type type,
  			    const char *name, int exclude)
  {
  	struct packed_git *found_pack = NULL;
  	off_t found_offset = 0;
  	uint32_t index_pos;
  
 -	if (have_duplicate_entry(sha1, exclude, &index_pos))
 +	if (have_duplicate_entry(oid, exclude, &index_pos))
  		return 0;
  
 -	if (!want_object_in_pack(sha1, exclude, &found_pack, &found_offset)) {
 +	if (!want_object_in_pack(oid, exclude, &found_pack, &found_offset)) {
  		/* The pack is missing an object, so it will not have closure */
  		if (write_bitmap_index) {
  			warning(_(no_closure_warning));
@@@ -1100,7 -1103,7 +1103,7 @@@
  		return 0;
  	}
  
 -	create_object_entry(sha1, type, pack_name_hash(name),
 +	create_object_entry(oid, type, pack_name_hash(name),
  			    exclude, name && no_try_delta(name),
  			    index_pos, found_pack, found_offset);
  
@@@ -1108,27 -1111,27 +1111,27 @@@
  	return 1;
  }
  
 -static int add_object_entry_from_bitmap(const unsigned char *sha1,
 +static int add_object_entry_from_bitmap(const struct object_id *oid,
  					enum object_type type,
  					int flags, uint32_t name_hash,
  					struct packed_git *pack, off_t offset)
  {
  	uint32_t index_pos;
  
 -	if (have_duplicate_entry(sha1, 0, &index_pos))
 +	if (have_duplicate_entry(oid, 0, &index_pos))
  		return 0;
  
 -	if (!want_object_in_pack(sha1, 0, &pack, &offset))
 +	if (!want_object_in_pack(oid, 0, &pack, &offset))
  		return 0;
  
 -	create_object_entry(sha1, type, name_hash, 0, 0, index_pos, pack, offset);
 +	create_object_entry(oid, type, name_hash, 0, 0, index_pos, pack, offset);
  
  	display_progress(progress_state, nr_result);
  	return 1;
  }
  
  struct pbase_tree_cache {
 -	unsigned char sha1[20];
 +	struct object_id oid;
  	int ref;
  	int temporary;
  	void *tree_data;
@@@ -1136,9 -1139,9 +1139,9 @@@
  };
  
  static struct pbase_tree_cache *(pbase_tree_cache[256]);
 -static int pbase_tree_cache_ix(const unsigned char *sha1)
 +static int pbase_tree_cache_ix(const struct object_id *oid)
  {
 -	return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 +	return oid->hash[0] % ARRAY_SIZE(pbase_tree_cache);
  }
  static int pbase_tree_cache_ix_incr(int ix)
  {
@@@ -1155,14 -1158,14 +1158,14 @@@ static struct pbase_tree 
  	struct pbase_tree_cache pcache;
  } *pbase_tree;
  
 -static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 +static struct pbase_tree_cache *pbase_tree_get(const struct object_id *oid)
  {
  	struct pbase_tree_cache *ent, *nent;
  	void *data;
  	unsigned long size;
  	enum object_type type;
  	int neigh;
 -	int my_ix = pbase_tree_cache_ix(sha1);
 +	int my_ix = pbase_tree_cache_ix(oid);
  	int available_ix = -1;
  
  	/* pbase-tree-cache acts as a limited hashtable.
@@@ -1171,7 -1174,7 +1174,7 @@@
  	 */
  	for (neigh = 0; neigh < 8; neigh++) {
  		ent = pbase_tree_cache[my_ix];
 -		if (ent && !hashcmp(ent->sha1, sha1)) {
 +		if (ent && !oidcmp(&ent->oid, oid)) {
  			ent->ref++;
  			return ent;
  		}
@@@ -1187,7 -1190,7 +1190,7 @@@
  	/* Did not find one.  Either we got a bogus request or
  	 * we need to read and perhaps cache.
  	 */
 -	data = read_sha1_file(sha1, &type, &size);
 +	data = read_sha1_file(oid->hash, &type, &size);
  	if (!data)
  		return NULL;
  	if (type != OBJ_TREE) {
@@@ -1213,7 -1216,7 +1216,7 @@@
  		free(ent->tree_data);
  		nent = ent;
  	}
 -	hashcpy(nent->sha1, sha1);
 +	oidcpy(&nent->oid, oid);
  	nent->tree_data = data;
  	nent->tree_size = size;
  	nent->ref = 1;
@@@ -1258,7 -1261,7 +1261,7 @@@ static void add_pbase_object(struct tre
  		if (cmp < 0)
  			return;
  		if (name[cmplen] != '/') {
 -			add_object_entry(entry.oid->hash,
 +			add_object_entry(entry.oid,
  					 object_type(entry.mode),
  					 fullname, 1);
  			return;
@@@ -1269,7 -1272,7 +1272,7 @@@
  			const char *down = name+cmplen+1;
  			int downlen = name_cmp_len(down);
  
 -			tree = pbase_tree_get(entry.oid->hash);
 +			tree = pbase_tree_get(entry.oid);
  			if (!tree)
  				return;
  			init_tree_desc(&sub, tree->tree_data, tree->tree_size);
@@@ -1328,7 -1331,7 +1331,7 @@@ static void add_preferred_base_object(c
  	cmplen = name_cmp_len(name);
  	for (it = pbase_tree; it; it = it->next) {
  		if (cmplen == 0) {
 -			add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 +			add_object_entry(&it->pcache.oid, OBJ_TREE, NULL, 1);
  		}
  		else {
  			struct tree_desc tree;
@@@ -1338,22 -1341,22 +1341,22 @@@
  	}
  }
  
 -static void add_preferred_base(unsigned char *sha1)
 +static void add_preferred_base(struct object_id *oid)
  {
  	struct pbase_tree *it;
  	void *data;
  	unsigned long size;
 -	unsigned char tree_sha1[20];
 +	struct object_id tree_oid;
  
  	if (window <= num_preferred_base++)
  		return;
  
 -	data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 +	data = read_object_with_reference(oid->hash, tree_type, &size, tree_oid.hash);
  	if (!data)
  		return;
  
  	for (it = pbase_tree; it; it = it->next) {
 -		if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 +		if (!oidcmp(&it->pcache.oid, &tree_oid)) {
  			free(data);
  			return;
  		}
@@@ -1363,7 -1366,7 +1366,7 @@@
  	it->next = pbase_tree;
  	pbase_tree = it;
  
 -	hashcpy(it->pcache.sha1, tree_sha1);
 +	oidcpy(&it->pcache.oid, &tree_oid);
  	it->pcache.tree_data = data;
  	it->pcache.tree_size = size;
  }
@@@ -2368,7 -2371,7 +2371,7 @@@ static void add_tag_chain(const struct 
  			die("unable to pack objects reachable from tag %s",
  			    oid_to_hex(oid));
  
 -		add_object_entry(tag->object.oid.hash, OBJ_TAG, NULL, 0);
 +		add_object_entry(&tag->object.oid, OBJ_TAG, NULL, 0);
  
  		if (tag->tagged->type != OBJ_TAG)
  			return;
@@@ -2382,7 -2385,7 +2385,7 @@@ static int add_ref_tag(const char *path
  	struct object_id peeled;
  
  	if (starts_with(path, "refs/tags/") && /* is a tag? */
 -	    !peel_ref(path, peeled.hash)    && /* peelable? */
 +	    !peel_ref(path, &peeled)    && /* peelable? */
  	    packlist_find(&to_pack, peeled.hash, NULL))      /* object packed? */
  		add_tag_chain(oid);
  	return 0;
@@@ -2516,9 -2519,8 +2519,9 @@@ static int git_pack_config(const char *
  
  static void read_object_list_from_stdin(void)
  {
 -	char line[40 + 1 + PATH_MAX + 2];
 -	unsigned char sha1[20];
 +	char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
 +	struct object_id oid;
 +	const char *p;
  
  	for (;;) {
  		if (!fgets(line, sizeof(line), stdin)) {
@@@ -2532,17 -2534,17 +2535,17 @@@
  			continue;
  		}
  		if (line[0] == '-') {
 -			if (get_sha1_hex(line+1, sha1))
 -				die("expected edge sha1, got garbage:\n %s",
 +			if (get_oid_hex(line+1, &oid))
 +				die("expected edge object ID, got garbage:\n %s",
  				    line);
 -			add_preferred_base(sha1);
 +			add_preferred_base(&oid);
  			continue;
  		}
 -		if (get_sha1_hex(line, sha1))
 -			die("expected sha1, got garbage:\n %s", line);
 +		if (parse_oid_hex(line, &oid, &p))
 +			die("expected object ID, got garbage:\n %s", line);
  
 -		add_preferred_base_object(line+41);
 -		add_object_entry(sha1, 0, line+41, 0);
 +		add_preferred_base_object(p + 1);
 +		add_object_entry(&oid, 0, p + 1, 0);
  	}
  }
  
@@@ -2550,7 -2552,7 +2553,7 @@@
  
  static void show_commit(struct commit *commit, void *data)
  {
 -	add_object_entry(commit->object.oid.hash, OBJ_COMMIT, NULL, 0);
 +	add_object_entry(&commit->object.oid, OBJ_COMMIT, NULL, 0);
  	commit->object.flags |= OBJECT_ADDED;
  
  	if (write_bitmap_index)
@@@ -2560,7 -2562,7 +2563,7 @@@
  static void show_object(struct object *obj, const char *name, void *data)
  {
  	add_preferred_base_object(name);
 -	add_object_entry(obj->oid.hash, obj->type, name, 0);
 +	add_object_entry(&obj->oid, obj->type, name, 0);
  	obj->flags |= OBJECT_ADDED;
  }
  
@@@ -2578,6 -2580,20 +2581,20 @@@ static void show_object__ma_allow_any(s
  	show_object(obj, name, data);
  }
  
+ static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
+ {
+ 	assert(arg_missing_action == MA_ALLOW_PROMISOR);
+ 
+ 	/*
+ 	 * Quietly ignore EXPECTED missing objects.  This avoids problems with
+ 	 * staging them now and getting an odd error later.
+ 	 */
+ 	if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
+ 		return;
+ 
+ 	show_object(obj, name, data);
+ }
+ 
  static int option_parse_missing_action(const struct option *opt,
  				       const char *arg, int unset)
  {
@@@ -2592,17 -2608,25 +2609,25 @@@
  
  	if (!strcmp(arg, "allow-any")) {
  		arg_missing_action = MA_ALLOW_ANY;
+ 		fetch_if_missing = 0;
  		fn_show_object = show_object__ma_allow_any;
  		return 0;
  	}
  
+ 	if (!strcmp(arg, "allow-promisor")) {
+ 		arg_missing_action = MA_ALLOW_PROMISOR;
+ 		fetch_if_missing = 0;
+ 		fn_show_object = show_object__ma_allow_promisor;
+ 		return 0;
+ 	}
+ 
  	die(_("invalid value for --missing"));
  	return 0;
  }
  
  static void show_edge(struct commit *commit)
  {
 -	add_preferred_base(commit->object.oid.hash);
 +	add_preferred_base(&commit->object.oid);
  }
  
  struct in_pack_object {
@@@ -2649,7 -2673,7 +2674,7 @@@ static void add_objects_in_unpacked_pac
  	memset(&in_pack, 0, sizeof(in_pack));
  
  	for (p = packed_git; p; p = p->next) {
 -		const unsigned char *sha1;
 +		struct object_id oid;
  		struct object *o;
  
  		if (!p->pack_local || p->pack_keep)
@@@ -2662,8 -2686,8 +2687,8 @@@
  			   in_pack.alloc);
  
  		for (i = 0; i < p->num_objects; i++) {
 -			sha1 = nth_packed_object_sha1(p, i);
 -			o = lookup_unknown_object(sha1);
 +			nth_packed_object_oid(&oid, p, i);
 +			o = lookup_unknown_object(oid.hash);
  			if (!(o->flags & OBJECT_ADDED))
  				mark_in_pack_object(o, p, &in_pack);
  			o->flags |= OBJECT_ADDED;
@@@ -2674,7 -2698,7 +2699,7 @@@
  		QSORT(in_pack.array, in_pack.nr, ofscmp);
  		for (i = 0; i < in_pack.nr; i++) {
  			struct object *o = in_pack.array[i].object;
 -			add_object_entry(o->oid.hash, o->type, "", 0);
 +			add_object_entry(&o->oid, o->type, "", 0);
  		}
  	}
  	free(in_pack.array);
@@@ -2690,7 -2714,7 +2715,7 @@@ static int add_loose_object(const struc
  		return 0;
  	}
  
 -	add_object_entry(oid->hash, type, "", 0);
 +	add_object_entry(oid, type, "", 0);
  	return 0;
  }
  
@@@ -2706,7 -2730,7 +2731,7 @@@ static void add_unreachable_loose_objec
  				      NULL, NULL, NULL);
  }
  
 -static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
 +static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
  {
  	static struct packed_git *last_found = (void *)1;
  	struct packed_git *p;
@@@ -2715,7 -2739,7 +2740,7 @@@
  
  	while (p) {
  		if ((!p->pack_local || p->pack_keep) &&
 -			find_pack_entry_one(sha1, p)) {
 +			find_pack_entry_one(oid->hash, p)) {
  			last_found = p;
  			return 1;
  		}
@@@ -2766,7 -2790,7 +2791,7 @@@ static void loosen_unused_packed_object
  		for (i = 0; i < p->num_objects; i++) {
  			nth_packed_object_oid(&oid, p, i);
  			if (!packlist_find(&to_pack, oid.hash, NULL) &&
 -			    !has_sha1_pack_kept_or_nonlocal(oid.hash) &&
 +			    !has_sha1_pack_kept_or_nonlocal(&oid) &&
  			    !loosened_object_can_be_discarded(&oid, p->mtime))
  				if (force_object_loose(oid.hash, p->mtime))
  					die("unable to force loose object");
@@@ -3009,6 -3033,8 +3034,8 @@@ int cmd_pack_objects(int argc, const ch
  		{ OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
  		  N_("handling for missing objects"), PARSE_OPT_NONEG,
  		  option_parse_missing_action },
+ 		OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
+ 			 N_("do not pack objects in promisor packfiles")),
  		OPT_END(),
  	};
  
@@@ -3054,6 -3080,12 +3081,12 @@@
  		argv_array_push(&rp, "--unpacked");
  	}
  
+ 	if (exclude_promisor_objects) {
+ 		use_internal_rev_list = 1;
+ 		fetch_if_missing = 0;
+ 		argv_array_push(&rp, "--exclude-promisor-objects");
+ 	}
+ 
  	if (!reuse_object)
  		reuse_delta = 0;
  	if (pack_compression_level == -1)
diff --combined builtin/prune.c
index d2fdae680a,be34645dcf..4cfec82f40
--- a/builtin/prune.c
+++ b/builtin/prune.c
@@@ -8,7 -8,7 +8,7 @@@
  #include "progress.h"
  
  static const char * const prune_usage[] = {
 -	N_("git prune [-n] [-v] [--expire <time>] [--] [<head>...]"),
 +	N_("git prune [-n] [-v] [--progress] [--expire <time>] [--] [<head>...]"),
  	NULL
  };
  static int show_only;
@@@ -101,12 -101,15 +101,15 @@@ int cmd_prune(int argc, const char **ar
  {
  	struct rev_info revs;
  	struct progress *progress = NULL;
+ 	int exclude_promisor_objects = 0;
  	const struct option options[] = {
  		OPT__DRY_RUN(&show_only, N_("do not remove, show only")),
  		OPT__VERBOSE(&verbose, N_("report pruned objects")),
  		OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
  		OPT_EXPIRY_DATE(0, "expire", &expire,
  				N_("expire objects older than <time>")),
+ 		OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
+ 			 N_("limit traversal to objects outside promisor packfiles")),
  		OPT_END()
  	};
  	char *s;
@@@ -139,6 -142,10 +142,10 @@@
  		show_progress = isatty(2);
  	if (show_progress)
  		progress = start_delayed_progress(_("Checking connectivity"), 0);
+ 	if (exclude_promisor_objects) {
+ 		fetch_if_missing = 0;
+ 		revs.exclude_promisor_objects = 1;
+ 	}
  
  	mark_reachable_objects(&revs, 1, expire, progress);
  	stop_progress(&progress);
diff --combined builtin/rev-list.c
index d5345b6a2e,48f922d709..e27aa1fc07
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@@ -15,6 -15,7 +15,7 @@@
  #include "progress.h"
  #include "reflog-walk.h"
  #include "oidset.h"
+ #include "packfile.h"
  
  static const char rev_list_usage[] =
  "git rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
@@@ -67,6 -68,7 +68,7 @@@ enum missing_action 
  	MA_ERROR = 0,    /* fail if any missing objects are encountered */
  	MA_ALLOW_ANY,    /* silently allow ALL missing objects */
  	MA_PRINT,        /* print ALL missing objects in special section */
+ 	MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
  };
  static enum missing_action arg_missing_action;
  
@@@ -197,6 -199,12 +199,12 @@@ static void finish_commit(struct commi
  
  static inline void finish_object__ma(struct object *obj)
  {
+ 	/*
+ 	 * Whether or not we try to dynamically fetch missing objects
+ 	 * from the server, we currently DO NOT have the object.  We
+ 	 * can either print, allow (ignore), or conditionally allow
+ 	 * (ignore) them.
+ 	 */
  	switch (arg_missing_action) {
  	case MA_ERROR:
  		die("missing blob object '%s'", oid_to_hex(&obj->oid));
@@@ -209,25 -217,36 +217,36 @@@
  		oidset_insert(&missing_objects, &obj->oid);
  		return;
  
+ 	case MA_ALLOW_PROMISOR:
+ 		if (is_promisor_object(&obj->oid))
+ 			return;
+ 		die("unexpected missing blob object '%s'",
+ 		    oid_to_hex(&obj->oid));
+ 		return;
+ 
  	default:
  		BUG("unhandled missing_action");
  		return;
  	}
  }
  
- static void finish_object(struct object *obj, const char *name, void *cb_data)
+ static int finish_object(struct object *obj, const char *name, void *cb_data)
  {
  	struct rev_list_info *info = cb_data;
- 	if (obj->type == OBJ_BLOB && !has_object_file(&obj->oid))
+ 	if (obj->type == OBJ_BLOB && !has_object_file(&obj->oid)) {
  		finish_object__ma(obj);
+ 		return 1;
+ 	}
  	if (info->revs->verify_objects && !obj->parsed && obj->type != OBJ_COMMIT)
  		parse_object(&obj->oid);
+ 	return 0;
  }
  
  static void show_object(struct object *obj, const char *name, void *cb_data)
  {
  	struct rev_list_info *info = cb_data;
- 	finish_object(obj, name, cb_data);
+ 	if (finish_object(obj, name, cb_data))
+ 		return;
  	display_progress(progress, ++progress_counter);
  	if (info->flags & REV_LIST_QUIET)
  		return;
@@@ -295,14 -314,14 +314,14 @@@ static int show_bisect_vars(struct rev_
  }
  
  static int show_object_fast(
 -	const unsigned char *sha1,
 +	const struct object_id *oid,
  	enum object_type type,
  	int exclude,
  	uint32_t name_hash,
  	struct packed_git *found_pack,
  	off_t found_offset)
  {
 -	fprintf(stdout, "%s\n", sha1_to_hex(sha1));
 +	fprintf(stdout, "%s\n", oid_to_hex(oid));
  	return 1;
  }
  
@@@ -315,11 -334,19 +334,19 @@@ static inline int parse_missing_action_
  
  	if (!strcmp(value, "allow-any")) {
  		arg_missing_action = MA_ALLOW_ANY;
+ 		fetch_if_missing = 0;
  		return 1;
  	}
  
  	if (!strcmp(value, "print")) {
  		arg_missing_action = MA_PRINT;
+ 		fetch_if_missing = 0;
+ 		return 1;
+ 	}
+ 
+ 	if (!strcmp(value, "allow-promisor")) {
+ 		arg_missing_action = MA_ALLOW_PROMISOR;
+ 		fetch_if_missing = 0;
  		return 1;
  	}
  
@@@ -344,6 -371,35 +371,35 @@@ int cmd_rev_list(int argc, const char *
  	init_revisions(&revs, prefix);
  	revs.abbrev = DEFAULT_ABBREV;
  	revs.commit_format = CMIT_FMT_UNSPECIFIED;
+ 
+ 	/*
+ 	 * Scan the argument list before invoking setup_revisions(), so that we
+ 	 * know if fetch_if_missing needs to be set to 0.
+ 	 *
+ 	 * "--exclude-promisor-objects" acts as a pre-filter on missing objects
+ 	 * by not crossing the boundary from realized objects to promisor
+ 	 * objects.
+ 	 *
+ 	 * Let "--missing" to conditionally set fetch_if_missing.
+ 	 */
+ 	for (i = 1; i < argc; i++) {
+ 		const char *arg = argv[i];
+ 		if (!strcmp(arg, "--exclude-promisor-objects")) {
+ 			fetch_if_missing = 0;
+ 			revs.exclude_promisor_objects = 1;
+ 			break;
+ 		}
+ 	}
+ 	for (i = 1; i < argc; i++) {
+ 		const char *arg = argv[i];
+ 		if (skip_prefix(arg, "--missing=", &arg)) {
+ 			if (revs.exclude_promisor_objects)
+ 				die(_("cannot combine --exclude-promisor-objects and --missing"));
+ 			if (parse_missing_action_value(arg))
+ 				break;
+ 		}
+ 	}
+ 
  	argc = setup_revisions(argc, argv, &revs, NULL);
  
  	memset(&info, 0, sizeof(info));
@@@ -351,7 -407,7 +407,7 @@@
  	if (revs.bisect)
  		bisect_list = 1;
  
 -	if (DIFF_OPT_TST(&revs.diffopt, QUICK))
 +	if (revs.diffopt.flags.quick)
  		info.flags |= REV_LIST_QUIET;
  	for (i = 1 ; i < argc; i++) {
  		const char *arg = argv[i];
@@@ -412,9 -468,10 +468,10 @@@
  			continue;
  		}
  
- 		if (skip_prefix(arg, "--missing=", &arg) &&
- 		    parse_missing_action_value(arg))
- 			continue;
+ 		if (!strcmp(arg, "--exclude-promisor-objects"))
+ 			continue; /* already handled above */
+ 		if (skip_prefix(arg, "--missing=", &arg))
+ 			continue; /* already handled above */
  
  		usage(rev_list_usage);
  
@@@ -481,7 -538,8 +538,7 @@@
  	if (bisect_list) {
  		int reaches = reaches, all = all;
  
 -		revs.commits = find_bisection(revs.commits, &reaches, &all,
 -					      bisect_find_all);
 +		find_bisection(&revs.commits, &reaches, &all, bisect_find_all);
  
  		if (bisect_show_vars)
  			return show_bisect_vars(&info, reaches, all);
diff --combined cache.h
index d8b975a571,6980072132..23413fdcb7
--- a/cache.h
+++ b/cache.h
@@@ -14,7 -14,6 +14,7 @@@
  #include "hash.h"
  #include "path.h"
  #include "sha1-array.h"
 +#include "repository.h"
  
  #ifndef platform_SHA_CTX
  /*
@@@ -78,8 -77,6 +78,8 @@@ struct object_id 
  	unsigned char hash[GIT_MAX_RAWSZ];
  };
  
 +#define the_hash_algo the_repository->hash_algo
 +
  #if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
  #define DTYPE(de)	((de)->d_type)
  #else
@@@ -207,7 -204,6 +207,7 @@@ struct cache_entry 
  #define CE_ADDED             (1 << 19)
  
  #define CE_HASHED            (1 << 20)
 +#define CE_FSMONITOR_VALID   (1 << 21)
  #define CE_WT_REMOVE         (1 << 22) /* remove in work directory */
  #define CE_CONFLICTED        (1 << 23)
  
@@@ -331,7 -327,6 +331,7 @@@ static inline unsigned int canon_mode(u
  #define CACHE_TREE_CHANGED	(1 << 5)
  #define SPLIT_INDEX_ORDERED	(1 << 6)
  #define UNTRACKED_CHANGED	(1 << 7)
 +#define FSMONITOR_CHANGED	(1 << 8)
  
  struct split_index;
  struct untracked_cache;
@@@ -350,8 -345,6 +350,8 @@@ struct index_state 
  	struct hashmap dir_hash;
  	unsigned char sha1[20];
  	struct untracked_cache *untracked;
 +	uint64_t fsmonitor_last_update;
 +	struct ewah_bitmap *fsmonitor_dirty;
  };
  
  extern struct index_state the_index;
@@@ -453,16 -446,6 +453,16 @@@ static inline enum object_type object_t
  #define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
  #define GIT_OPTIONAL_LOCKS_ENVIRONMENT "GIT_OPTIONAL_LOCKS"
  
 +/*
 + * Environment variable used in handshaking the wire protocol.
 + * Contains a colon ':' separated list of keys with optional values
 + * 'key[=value]'.  Presence of unknown keys and values must be
 + * ignored.
 + */
 +#define GIT_PROTOCOL_ENVIRONMENT "GIT_PROTOCOL"
 +/* HTTP header used to handshake the wire protocol */
 +#define GIT_PROTOCOL_HEADER "Git-Protocol"
 +
  /*
   * This environment variable is expected to contain a boolean indicating
   * whether we should or should not treat:
@@@ -619,40 -602,12 +619,40 @@@ extern int do_read_index(struct index_s
  extern int read_index_from(struct index_state *, const char *path);
  extern int is_index_unborn(struct index_state *);
  extern int read_index_unmerged(struct index_state *);
 +
 +/* For use with `write_locked_index()`. */
  #define COMMIT_LOCK		(1 << 0)
 -#define CLOSE_LOCK		(1 << 1)
 +
 +/*
 + * Write the index while holding an already-taken lock. Close the lock,
 + * and if `COMMIT_LOCK` is given, commit it.
 + *
 + * Unless a split index is in use, write the index into the lockfile.
 + *
 + * With a split index, write the shared index to a temporary file,
 + * adjust its permissions and rename it into place, then write the
 + * split index to the lockfile. If the temporary file for the shared
 + * index cannot be created, fall back to the behavior described in
 + * the previous paragraph.
 + *
 + * With `COMMIT_LOCK`, the lock is always committed or rolled back.
 + * Without it, the lock is closed, but neither committed nor rolled
 + * back.
 + */
  extern int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);
 +
  extern int discard_index(struct index_state *);
  extern void move_index_extensions(struct index_state *dst, struct index_state *src);
  extern int unmerged_index(const struct index_state *);
 +
 +/**
 + * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
 + * branch, returns 1 if there are entries in the index, 0 otherwise. If an
 + * strbuf is provided, the space-separated list of files that differ will be
 + * appended to it.
 + */
 +extern int index_has_changes(struct strbuf *sb);
 +
  extern int verify_path(const char *path);
  extern int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
  extern int index_dir_exists(struct index_state *istate, const char *name, int namelen);
@@@ -726,14 -681,11 +726,14 @@@ extern void *read_blob_data_from_index(
  #define CE_MATCH_IGNORE_MISSING		0x08
  /* enable stat refresh */
  #define CE_MATCH_REFRESH		0x10
 -extern int ie_match_stat(const struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 -extern int ie_modified(const struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 +/* don't refresh_fsmonitor state or do stat comparison even if CE_FSMONITOR_VALID is true */
 +#define CE_MATCH_IGNORE_FSMONITOR 0X20
 +extern int ie_match_stat(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
 +extern int ie_modified(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
  
  #define HASH_WRITE_OBJECT 1
  #define HASH_FORMAT_CHECK 2
 +#define HASH_RENORMALIZE  4
  extern int index_fd(struct object_id *oid, int fd, struct stat *st, enum object_type type, const char *path, unsigned flags);
  extern int index_path(struct object_id *oid, const char *path, struct stat *st, unsigned flags);
  
@@@ -764,17 -716,12 +764,17 @@@ extern void fill_stat_cache_info(struc
  extern int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
  extern struct cache_entry *refresh_cache_entry(struct cache_entry *, unsigned int);
  
 +/*
 + * Opportunistically update the index but do not complain if we can't.
 + * The lockfile is always committed or rolled back.
 + */
  extern void update_index_if_able(struct index_state *, struct lock_file *);
  
  extern int hold_locked_index(struct lock_file *, int);
  extern void set_alternate_index_output(const char *);
  
  extern int verify_index_checksum;
 +extern int verify_ce_order;
  
  /* Environment bits from configuration mechanism */
  extern int trust_executable_bit;
@@@ -828,7 -775,6 +828,7 @@@ extern int core_apply_sparse_checkout
  extern int precomposed_unicode;
  extern int protect_hfs;
  extern int protect_ntfs;
 +extern const char *core_fsmonitor;
  
  /*
   * Include broken refs in all ref iterations, which will
@@@ -914,12 -860,13 +914,14 @@@ extern int grafts_replace_parents
  #define GIT_REPO_VERSION 0
  #define GIT_REPO_VERSION_READ 1
  extern int repository_format_precious_objects;
+ extern char *repository_format_partial_clone;
  
  struct repository_format {
  	int version;
  	int precious_objects;
+ 	char *partial_clone; /* value of extensions.partialclone */
  	int is_bare;
 +	int hash_algo;
  	char *work_tree;
  	struct string_list unknown_extensions;
  };
@@@ -1052,22 -999,22 +1054,22 @@@ extern const struct object_id empty_blo
  
  static inline int is_empty_blob_sha1(const unsigned char *sha1)
  {
 -	return !hashcmp(sha1, EMPTY_BLOB_SHA1_BIN);
 +	return !hashcmp(sha1, the_hash_algo->empty_blob->hash);
  }
  
  static inline int is_empty_blob_oid(const struct object_id *oid)
  {
 -	return !hashcmp(oid->hash, EMPTY_BLOB_SHA1_BIN);
 +	return !oidcmp(oid, the_hash_algo->empty_blob);
  }
  
  static inline int is_empty_tree_sha1(const unsigned char *sha1)
  {
 -	return !hashcmp(sha1, EMPTY_TREE_SHA1_BIN);
 +	return !hashcmp(sha1, the_hash_algo->empty_tree->hash);
  }
  
  static inline int is_empty_tree_oid(const struct object_id *oid)
  {
 -	return !hashcmp(oid->hash, EMPTY_TREE_SHA1_BIN);
 +	return !oidcmp(oid, the_hash_algo->empty_tree);
  }
  
  /* set default permissions by passing mode arguments to open(2) */
@@@ -1372,13 -1319,6 +1374,13 @@@ extern int set_disambiguate_hint_config
  extern int get_sha1_hex(const char *hex, unsigned char *sha1);
  extern int get_oid_hex(const char *hex, struct object_id *sha1);
  
 +/*
 + * Read `len` pairs of hexadecimal digits from `hex` and write the
 + * values to `binary` as `len` bytes. Return 0 on success, or -1 if
 + * the input does not consist of hex digits).
 + */
 +extern int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);
 +
  /*
   * Convert a binary sha1 to its hex equivalent. The `_r` variant is reentrant,
   * and writes the NUL-terminated output to the buffer `out`, which must be at
@@@ -1500,7 -1440,6 +1502,7 @@@ extern const char *ident_default_name(v
  extern const char *ident_default_email(void);
  extern const char *git_editor(void);
  extern const char *git_pager(int stdout_is_tty);
 +extern int is_terminal_dumb(void);
  extern int git_ident_config(const char *, const char *, void *);
  extern void reset_ident_date(void);
  
@@@ -1648,7 -1587,8 +1650,8 @@@ extern struct packed_git 
  	unsigned pack_local:1,
  		 pack_keep:1,
  		 freshened:1,
- 		 do_not_close:1;
+ 		 do_not_close:1,
+ 		 pack_promisor:1;
  	unsigned char sha1[20];
  	struct revindex_entry *revindex;
  	/* something like ".git/objects/pack/xxxxx.pack" */
@@@ -1787,6 -1727,14 +1790,14 @@@ struct object_info 
  #define OBJECT_INFO_QUICK 8
  extern int sha1_object_info_extended(const unsigned char *, struct object_info *, unsigned flags);
  
+ /*
+  * Set this to 0 to prevent sha1_object_info_extended() from fetching missing
+  * blobs. This has a difference only if extensions.partialClone is set.
+  *
+  * Its default value is 1.
+  */
+ extern int fetch_if_missing;
+ 
  /* Dumb servers support */
  extern int update_server_info(int);
  
@@@ -1982,10 -1930,4 +1993,10 @@@ void sleep_millisec(int millisec)
   */
  void safe_create_dir(const char *dir, int share);
  
 +/*
 + * Should we print an ellipsis after an abbreviated SHA-1 value
 + * when doing diff-raw output or indicating a detached HEAD?
 + */
 +extern int print_sha1_ellipsis(void);
 +
  #endif /* CACHE_H */
diff --combined environment.c
index 63ac38a46f,e52aab3ea4..835bb75c4e
--- a/environment.c
+++ b/environment.c
@@@ -27,6 -27,7 +27,7 @@@ int warn_ambiguous_refs = 1
  int warn_on_object_refname_ambiguity = 1;
  int ref_paranoia = -1;
  int repository_format_precious_objects;
+ char *repository_format_partial_clone;
  const char *git_commit_encoding;
  const char *git_log_output_encoding;
  const char *apply_default_whitespace;
@@@ -76,7 -77,6 +77,7 @@@ int protect_hfs = PROTECT_HFS_DEFAULT
  #define PROTECT_NTFS_DEFAULT 0
  #endif
  int protect_ntfs = PROTECT_NTFS_DEFAULT;
 +const char *core_fsmonitor;
  
  /*
   * The character that begins a commented line in user-editable file
@@@ -344,18 -344,3 +345,18 @@@ int use_optional_locks(void
  {
  	return git_env_bool(GIT_OPTIONAL_LOCKS_ENVIRONMENT, 1);
  }
 +
 +int print_sha1_ellipsis(void)
 +{
 +	/*
 +	 * Determine if the calling environment contains the variable
 +	 * GIT_PRINT_SHA1_ELLIPSIS set to "yes".
 +	 */
 +	static int cached_result = -1; /* unknown */
 +
 +	if (cached_result < 0) {
 +		const char *v = getenv("GIT_PRINT_SHA1_ELLIPSIS");
 +		cached_result = (v && !strcasecmp(v, "yes"));
 +	}
 +	return cached_result;
 +}
diff --combined fetch-pack.c
index 9f6b07ad91,0798e0b8b2..7aa1f58995
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@@ -450,6 -450,8 +450,8 @@@ static int find_common(struct fetch_pac
  
  	flushes = 0;
  	retval = -1;
+ 	if (args->no_dependents)
+ 		goto done;
  	while ((oid = get_rev())) {
  		packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
  		print_verbose(args, "have %s", oid_to_hex(oid));
@@@ -716,8 -718,7 +718,8 @@@ static int everything_local(struct fetc
  	for (ref = *refs; ref; ref = ref->next) {
  		struct object *o;
  
 -		if (!has_object_file(&ref->old_oid))
 +		if (!has_object_file_with_flags(&ref->old_oid,
 +						OBJECT_INFO_QUICK))
  			continue;
  
  		o = parse_object(&ref->old_oid);
@@@ -735,29 -736,31 +737,31 @@@
  		}
  	}
  
- 	if (!args->deepen) {
- 		for_each_ref(mark_complete_oid, NULL);
- 		for_each_cached_alternate(mark_alternate_complete);
- 		commit_list_sort_by_date(&complete);
- 		if (cutoff)
- 			mark_recent_complete_commits(args, cutoff);
- 	}
+ 	if (!args->no_dependents) {
+ 		if (!args->deepen) {
+ 			for_each_ref(mark_complete_oid, NULL);
+ 			for_each_cached_alternate(mark_alternate_complete);
+ 			commit_list_sort_by_date(&complete);
+ 			if (cutoff)
+ 				mark_recent_complete_commits(args, cutoff);
+ 		}
  
- 	/*
- 	 * Mark all complete remote refs as common refs.
- 	 * Don't mark them common yet; the server has to be told so first.
- 	 */
- 	for (ref = *refs; ref; ref = ref->next) {
- 		struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
- 					     NULL, 0);
+ 		/*
+ 		 * Mark all complete remote refs as common refs.
+ 		 * Don't mark them common yet; the server has to be told so first.
+ 		 */
+ 		for (ref = *refs; ref; ref = ref->next) {
+ 			struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
+ 						     NULL, 0);
  
- 		if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
- 			continue;
+ 			if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
+ 				continue;
  
- 		if (!(o->flags & SEEN)) {
- 			rev_list_push((struct commit *)o, COMMON_REF | SEEN);
+ 			if (!(o->flags & SEEN)) {
+ 				rev_list_push((struct commit *)o, COMMON_REF | SEEN);
  
- 			mark_common((struct commit *)o, 1, 1);
+ 				mark_common((struct commit *)o, 1, 1);
+ 			}
  		}
  	}
  
@@@ -833,7 -836,7 +837,7 @@@ static int get_pack(struct fetch_pack_a
  		argv_array_push(&cmd.args, alternate_shallow_file);
  	}
  
- 	if (do_keep) {
+ 	if (do_keep || args->from_promisor) {
  		if (pack_lockfile)
  			cmd.out = -1;
  		cmd_name = "index-pack";
@@@ -843,7 -846,7 +847,7 @@@
  			argv_array_push(&cmd.args, "-v");
  		if (args->use_thin_pack)
  			argv_array_push(&cmd.args, "--fix-thin");
- 		if (args->lock_pack || unpack_limit) {
+ 		if (do_keep && (args->lock_pack || unpack_limit)) {
  			char hostname[HOST_NAME_MAX + 1];
  			if (xgethostname(hostname, sizeof(hostname)))
  				xsnprintf(hostname, sizeof(hostname), "localhost");
@@@ -853,6 -856,8 +857,8 @@@
  		}
  		if (args->check_self_contained_and_connected)
  			argv_array_push(&cmd.args, "--check-self-contained-and-connected");
+ 		if (args->from_promisor)
+ 			argv_array_push(&cmd.args, "--promisor");
  	}
  	else {
  		cmd_name = "unpack-objects";
diff --combined list-objects.c
index 0966cdc9fa,58621fc6ee..168bef688a
--- a/list-objects.c
+++ b/list-objects.c
@@@ -9,6 -9,7 +9,7 @@@
  #include "list-objects.h"
  #include "list-objects-filter.h"
  #include "list-objects-filter-options.h"
+ #include "packfile.h"
  
  static void process_blob(struct rev_info *revs,
  			 struct blob *blob,
@@@ -30,6 -31,20 +31,20 @@@
  	if (obj->flags & (UNINTERESTING | SEEN))
  		return;
  
+ 	/*
+ 	 * Pre-filter known-missing objects when explicitly requested.
+ 	 * Otherwise, a missing object error message may be reported
+ 	 * later (depending on other filtering criteria).
+ 	 *
+ 	 * Note that this "--exclude-promisor-objects" pre-filtering
+ 	 * may cause the actual filter to report an incomplete list
+ 	 * of missing objects.
+ 	 */
+ 	if (revs->exclude_promisor_objects &&
+ 	    !has_object_file(&obj->oid) &&
+ 	    is_promisor_object(&obj->oid))
+ 		return;
+ 
  	pathlen = path->len;
  	strbuf_addstr(path, name);
  	if (filter_fn)
@@@ -91,6 -106,8 +106,8 @@@ static void process_tree(struct rev_inf
  		all_entries_interesting: entry_not_interesting;
  	int baselen = base->len;
  	enum list_objects_filter_result r = LOFR_MARK_SEEN | LOFR_DO_SHOW;
+ 	int gently = revs->ignore_missing_links ||
+ 		     revs->exclude_promisor_objects;
  
  	if (!revs->tree_objects)
  		return;
@@@ -98,9 -115,19 +115,19 @@@
  		die("bad tree object");
  	if (obj->flags & (UNINTERESTING | SEEN))
  		return;
- 	if (parse_tree_gently(tree, revs->ignore_missing_links) < 0) {
+ 	if (parse_tree_gently(tree, gently) < 0) {
  		if (revs->ignore_missing_links)
  			return;
+ 
+ 		/*
+ 		 * Pre-filter known-missing tree objects when explicitly
+ 		 * requested.  This may cause the actual filter to report
+ 		 * an incomplete list of missing objects.
+ 		 */
+ 		if (revs->exclude_promisor_objects &&
+ 		    is_promisor_object(&obj->oid))
+ 			return;
+ 
  		die("bad tree object %s", oid_to_hex(&obj->oid));
  	}
  
@@@ -214,17 -241,27 +241,17 @@@ static void add_pending_tree(struct rev
  	add_pending_object(revs, &tree->object, "");
  }
  
 -static void do_traverse(struct rev_info *revs,
 -			show_commit_fn show_commit,
 -			show_object_fn show_object,
 -			void *show_data,
 -			filter_object_fn filter_fn,
 -			void *filter_data)
 +static void traverse_trees_and_blobs(struct rev_info *revs,
 +				     struct strbuf *base,
 +				     show_object_fn show_object,
 +				     void *show_data,
 +				     filter_object_fn filter_fn,
 +				     void *filter_data)
  {
  	int i;
 -	struct commit *commit;
 -	struct strbuf base;
  
 -	strbuf_init(&base, PATH_MAX);
 -	while ((commit = get_revision(revs)) != NULL) {
 -		/*
 -		 * an uninteresting boundary commit may not have its tree
 -		 * parsed yet, but we are not going to show them anyway
 -		 */
 -		if (commit->tree)
 -			add_pending_tree(revs, commit->tree);
 -		show_commit(commit, show_data);
 -	}
 +	assert(base->len == 0);
 +
  	for (i = 0; i < revs->pending.nr; i++) {
  		struct object_array_entry *pending = revs->pending.objects + i;
  		struct object *obj = pending->item;
@@@ -241,13 -278,13 +268,13 @@@
  			path = "";
  		if (obj->type == OBJ_TREE) {
  			process_tree(revs, (struct tree *)obj, show_object,
 -				     &base, path, show_data,
 +				     base, path, show_data,
  				     filter_fn, filter_data);
  			continue;
  		}
  		if (obj->type == OBJ_BLOB) {
  			process_blob(revs, (struct blob *)obj, show_object,
 -				     &base, path, show_data,
 +				     base, path, show_data,
  				     filter_fn, filter_data);
  			continue;
  		}
@@@ -255,42 -292,7 +282,42 @@@
  		    oid_to_hex(&obj->oid), name);
  	}
  	object_array_clear(&revs->pending);
 -	strbuf_release(&base);
 +}
 +
 +static void do_traverse(struct rev_info *revs,
 +			show_commit_fn show_commit,
 +			show_object_fn show_object,
 +			void *show_data,
 +			filter_object_fn filter_fn,
 +			void *filter_data)
 +{
 +	struct commit *commit;
 +	struct strbuf csp; /* callee's scratch pad */
 +	strbuf_init(&csp, PATH_MAX);
 +
 +	while ((commit = get_revision(revs)) != NULL) {
 +		/*
 +		 * an uninteresting boundary commit may not have its tree
 +		 * parsed yet, but we are not going to show them anyway
 +		 */
 +		if (commit->tree)
 +			add_pending_tree(revs, commit->tree);
 +		show_commit(commit, show_data);
 +
 +		if (revs->tree_blobs_in_commit_order)
 +			/*
 +			 * NEEDSWORK: Adding the tree and then flushing it here
 +			 * needs a reallocation for each commit. Can we pass the
 +			 * tree directory without allocation churn?
 +			 */
 +			traverse_trees_and_blobs(revs, &csp,
 +						 show_object, show_data,
 +						 filter_fn, filter_data);
 +	}
 +	traverse_trees_and_blobs(revs, &csp,
 +				 show_object, show_data,
 +				 filter_fn, filter_data);
 +	strbuf_release(&csp);
  }
  
  void traverse_commit_list(struct rev_info *revs,
diff --combined object.c
index 0afdfd19b7,4c222d6260..9e6f9ff20b
--- a/object.c
+++ b/object.c
@@@ -252,7 -252,7 +252,7 @@@ struct object *parse_object(const struc
  	if (obj && obj->parsed)
  		return obj;
  
- 	if ((obj && obj->type == OBJ_BLOB) ||
+ 	if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
  	    (!obj && has_object_file(oid) &&
  	     sha1_object_info(oid->hash, NULL) == OBJ_BLOB)) {
  		if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
@@@ -434,14 -434,3 +434,14 @@@ void clear_object_flags(unsigned flags
  			obj->flags &= ~flags;
  	}
  }
 +
 +void clear_commit_marks_all(unsigned int flags)
 +{
 +	int i;
 +
 +	for (i = 0; i < obj_hash_size; i++) {
 +		struct object *obj = obj_hash[i];
 +		if (obj && obj->type == OBJ_COMMIT)
 +			obj->flags &= ~flags;
 +	}
 +}
diff --combined revision.c
index a60628fbff,05a7aac063..236d0d579f
--- a/revision.c
+++ b/revision.c
@@@ -198,6 -198,8 +198,8 @@@ static struct object *get_reference(str
  	if (!object) {
  		if (revs->ignore_missing)
  			return object;
+ 		if (revs->exclude_promisor_objects && is_promisor_object(oid))
+ 			return NULL;
  		die("bad object %s", name);
  	}
  	object->flags |= flags;
@@@ -395,16 -397,8 +397,16 @@@ static struct commit *one_relevant_pare
   * if the whole diff is removal of old data, and otherwise
   * REV_TREE_DIFFERENT (of course if the trees are the same we
   * want REV_TREE_SAME).
 - * That means that once we get to REV_TREE_DIFFERENT, we do not
 - * have to look any further.
 + *
 + * The only time we care about the distinction is when
 + * remove_empty_trees is in effect, in which case we care only about
 + * whether the whole change is REV_TREE_NEW, or if there's another type
 + * of change. Which means we can stop the diff early in either of these
 + * cases:
 + *
 + *   1. We're not using remove_empty_trees at all.
 + *
 + *   2. We saw anything except REV_TREE_NEW.
   */
  static int tree_difference = REV_TREE_SAME;
  
@@@ -415,11 -409,10 +417,11 @@@ static void file_add_remove(struct diff
  		    const char *fullpath, unsigned dirty_submodule)
  {
  	int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 +	struct rev_info *revs = options->change_fn_data;
  
  	tree_difference |= diff;
 -	if (tree_difference == REV_TREE_DIFFERENT)
 -		DIFF_OPT_SET(options, HAS_CHANGES);
 +	if (!revs->remove_empty_trees || tree_difference != REV_TREE_NEW)
 +		options->flags.has_changes = 1;
  }
  
  static void file_change(struct diff_options *options,
@@@ -431,7 -424,7 +433,7 @@@
  		 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
  {
  	tree_difference = REV_TREE_DIFFERENT;
 -	DIFF_OPT_SET(options, HAS_CHANGES);
 +	options->flags.has_changes = 1;
  }
  
  static int rev_compare_tree(struct rev_info *revs,
@@@ -464,7 -457,7 +466,7 @@@
  	}
  
  	tree_difference = REV_TREE_SAME;
 -	DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 +	revs->pruning.flags.has_changes = 0;
  	if (diff_tree_oid(&t1->object.oid, &t2->object.oid, "",
  			   &revs->pruning) < 0)
  		return REV_TREE_DIFFERENT;
@@@ -480,7 -473,7 +482,7 @@@ static int rev_same_tree_as_empty(struc
  		return 0;
  
  	tree_difference = REV_TREE_SAME;
 -	DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 +	revs->pruning.flags.has_changes = 0;
  	retval = diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);
  
  	return retval >= 0 && (tree_difference == REV_TREE_SAME);
@@@ -799,9 -792,17 +801,17 @@@ static int add_parents_to_list(struct r
  
  	for (parent = commit->parents; parent; parent = parent->next) {
  		struct commit *p = parent->item;
- 
- 		if (parse_commit_gently(p, revs->ignore_missing_links) < 0)
+ 		int gently = revs->ignore_missing_links ||
+ 			     revs->exclude_promisor_objects;
+ 		if (parse_commit_gently(p, gently) < 0) {
+ 			if (revs->exclude_promisor_objects &&
+ 			    is_promisor_object(&p->object.oid)) {
+ 				if (revs->first_parent_only)
+ 					break;
+ 				continue;
+ 			}
  			return -1;
+ 		}
  		if (revs->show_source && !p->util)
  			p->util = commit->util;
  		p->object.flags |= left_flag;
@@@ -1412,11 -1413,10 +1422,11 @@@ void init_revisions(struct rev_info *re
  	revs->abbrev = DEFAULT_ABBREV;
  	revs->ignore_merges = 1;
  	revs->simplify_history = 1;
 -	DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 -	DIFF_OPT_SET(&revs->pruning, QUICK);
 +	revs->pruning.flags.recursive = 1;
 +	revs->pruning.flags.quick = 1;
  	revs->pruning.add_remove = file_add_remove;
  	revs->pruning.change = file_change;
 +	revs->pruning.change_fn_data = revs;
  	revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
  	revs->dense = 1;
  	revs->prefix = prefix;
@@@ -1832,7 -1832,7 +1842,7 @@@ static int handle_revision_opt(struct r
  		revs->simplify_by_decoration = 1;
  		revs->limited = 1;
  		revs->prune = 1;
 -		load_ref_decorations(DECORATE_SHORT_REFS);
 +		load_ref_decorations(NULL, DECORATE_SHORT_REFS);
  	} else if (!strcmp(arg, "--date-order")) {
  		revs->sort_order = REV_SORT_BY_COMMIT_DATE;
  		revs->topo_order = 1;
@@@ -1855,8 -1855,6 +1865,8 @@@
  		revs->dense = 0;
  	} else if (!strcmp(arg, "--show-all")) {
  		revs->show_all = 1;
 +	} else if (!strcmp(arg, "--in-commit-order")) {
 +		revs->tree_blobs_in_commit_order = 1;
  	} else if (!strcmp(arg, "--remove-empty")) {
  		revs->remove_empty_trees = 1;
  	} else if (!strcmp(arg, "--merges")) {
@@@ -1929,11 -1927,11 +1939,11 @@@
  		die("--unpacked=<packfile> no longer supported.");
  	} else if (!strcmp(arg, "-r")) {
  		revs->diff = 1;
 -		DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
 +		revs->diffopt.flags.recursive = 1;
  	} else if (!strcmp(arg, "-t")) {
  		revs->diff = 1;
 -		DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
 -		DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
 +		revs->diffopt.flags.recursive = 1;
 +		revs->diffopt.flags.tree_in_recursive = 1;
  	} else if (!strcmp(arg, "-m")) {
  		revs->ignore_merges = 0;
  	} else if (!strcmp(arg, "-c")) {
@@@ -2078,7 -2076,7 +2088,7 @@@
  		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
  	} else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
  		revs->grep_filter.ignore_case = 1;
 -		DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
 +		revs->diffopt.pickaxe_opts |= DIFF_PICKAXE_IGNORE_CASE;
  	} else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
  		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
  	} else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
@@@ -2100,6 -2098,10 +2110,10 @@@
  		revs->limited = 1;
  	} else if (!strcmp(arg, "--ignore-missing")) {
  		revs->ignore_missing = 1;
+ 	} else if (!strcmp(arg, "--exclude-promisor-objects")) {
+ 		if (fetch_if_missing)
+ 			die("BUG: exclude_promisor_objects can only be used when fetch_if_missing is 0");
+ 		revs->exclude_promisor_objects = 1;
  	} else {
  		int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
  		if (!opts)
@@@ -2409,21 -2411,18 +2423,21 @@@ int setup_revisions(int argc, const cha
  		revs->diff = 1;
  
  	/* Pickaxe, diff-filter and rename following need diffs */
 -	if (revs->diffopt.pickaxe ||
 +	if ((revs->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
  	    revs->diffopt.filter ||
 -	    DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
 +	    revs->diffopt.flags.follow_renames)
  		revs->diff = 1;
  
 +	if (revs->diffopt.objfind)
 +		revs->simplify_history = 0;
 +
  	if (revs->topo_order)
  		revs->limited = 1;
  
  	if (revs->prune_data.nr) {
  		copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
  		/* Can't prune commits with rename following: the paths change.. */
 -		if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
 +		if (!revs->diffopt.flags.follow_renames)
  			revs->prune = 1;
  		if (!revs->full_diff)
  			copy_pathspec(&revs->diffopt.pathspec,
@@@ -2845,6 -2844,16 +2859,16 @@@ void reset_revision_walk(void
  	clear_object_flags(SEEN | ADDED | SHOWN);
  }
  
+ static int mark_uninteresting(const struct object_id *oid,
+ 			      struct packed_git *pack,
+ 			      uint32_t pos,
+ 			      void *unused)
+ {
+ 	struct object *o = parse_object(oid);
+ 	o->flags |= UNINTERESTING | SEEN;
+ 	return 0;
+ }
+ 
  int prepare_revision_walk(struct rev_info *revs)
  {
  	int i;
@@@ -2865,13 -2874,19 +2889,18 @@@
  			}
  		}
  	}
 -	if (!revs->leak_pending)
 -		object_array_clear(&old_pending);
 +	object_array_clear(&old_pending);
  
  	/* Signal whether we need per-parent treesame decoration */
  	if (revs->simplify_merges ||
  	    (revs->limited && limiting_can_increase_treesame(revs)))
  		revs->treesame.name = "treesame";
  
+ 	if (revs->exclude_promisor_objects) {
+ 		for_each_packed_object(mark_uninteresting, NULL,
+ 				       FOR_EACH_OBJECT_PROMISOR_ONLY);
+ 	}
+ 
  	if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
  		commit_list_sort_by_date(&revs->commits);
  	if (revs->no_walk)
diff --combined revision.h
index d7a35c8c9e,5f9a49ca66..3dee97bfb9
--- a/revision.h
+++ b/revision.h
@@@ -4,7 -4,7 +4,7 @@@
  #include "parse-options.h"
  #include "grep.h"
  #include "notes.h"
 -#include "commit.h"
 +#include "pretty.h"
  #include "diff.h"
  
  /* Remember to update object flag allocation in object.h */
@@@ -122,7 -122,9 +122,10 @@@ struct rev_info 
  			ancestry_path:1,
  			first_parent_only:1,
  			line_level_traverse:1,
- 			tree_blobs_in_commit_order:1;
++			tree_blobs_in_commit_order:1,
+ 
+ 			/* for internal use only */
+ 			exclude_promisor_objects:1;
  
  	/* Diff flags */
  	unsigned int	diff:1,
@@@ -151,6 -153,18 +154,6 @@@
  			date_mode_explicit:1,
  			preserve_subject:1;
  	unsigned int	disable_stdin:1;
 -	/*
 -	 * Set `leak_pending` to prevent `prepare_revision_walk()` from clearing
 -	 * the array of pending objects (`pending`). It will still forget about
 -	 * the array and its entries, so they really are leaked. This can be
 -	 * useful if the `struct object_array` `pending` is copied before
 -	 * calling `prepare_revision_walk()`. By setting `leak_pending`, you
 -	 * effectively claim ownership of the old array, so you should most
 -	 * likely call `object_array_clear(&pending_copy)` once you are done.
 -	 * Observe that this is about ownership of the array and its entries,
 -	 * not the commits referenced by those entries.
 -	 */
 -	unsigned int	leak_pending:1;
  	/* --show-linear-break */
  	unsigned int	track_linear:1,
  			track_first_time:1,
diff --combined setup.c
index 8cc34186ce,58536bd6ee..c5d55dcee4
--- a/setup.c
+++ b/setup.c
@@@ -312,9 -312,7 +312,9 @@@ int is_git_directory(const char *suspec
  	size_t len;
  
  	/* Check worktree-related signatures */
 -	strbuf_addf(&path, "%s/HEAD", suspect);
 +	strbuf_addstr(&path, suspect);
 +	strbuf_complete(&path, '/');
 +	strbuf_addstr(&path, "HEAD");
  	if (validate_headref(path.buf))
  		goto done;
  
@@@ -422,7 -420,11 +422,11 @@@ static int check_repo_format(const cha
  			;
  		else if (!strcmp(ext, "preciousobjects"))
  			data->precious_objects = git_config_bool(var, value);
- 		else
+ 		else if (!strcmp(ext, "partialclone")) {
+ 			if (!value)
+ 				return config_error_nonbool(var);
+ 			data->partial_clone = xstrdup(value);
+ 		} else
  			string_list_append(&data->unknown_extensions, ext);
  	} else if (strcmp(var, "core.bare") == 0) {
  		data->is_bare = git_config_bool(var, value);
@@@ -434,15 -436,16 +438,15 @@@
  	return 0;
  }
  
 -static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 +static int check_repository_format_gently(const char *gitdir, struct repository_format *candidate, int *nongit_ok)
  {
  	struct strbuf sb = STRBUF_INIT;
  	struct strbuf err = STRBUF_INIT;
 -	struct repository_format candidate;
  	int has_common;
  
  	has_common = get_common_dir(&sb, gitdir);
  	strbuf_addstr(&sb, "/config");
 -	read_repository_format(&candidate, sb.buf);
 +	read_repository_format(candidate, sb.buf);
  	strbuf_release(&sb);
  
  	/*
@@@ -450,10 -453,10 +454,10 @@@
  	 * we treat a missing config as a silent "ok", even when nongit_ok
  	 * is unset.
  	 */
 -	if (candidate.version < 0)
 +	if (candidate->version < 0)
  		return 0;
  
 -	if (verify_repository_format(&candidate, &err) < 0) {
 +	if (verify_repository_format(candidate, &err) < 0) {
  		if (nongit_ok) {
  			warning("%s", err.buf);
  			strbuf_release(&err);
@@@ -463,21 -466,22 +467,22 @@@
  		die("%s", err.buf);
  	}
  
 -	repository_format_precious_objects = candidate.precious_objects;
 -	repository_format_partial_clone = candidate.partial_clone;
 -	string_list_clear(&candidate.unknown_extensions, 0);
 +	repository_format_precious_objects = candidate->precious_objects;
++	repository_format_partial_clone = candidate->partial_clone;
 +	string_list_clear(&candidate->unknown_extensions, 0);
  	if (!has_common) {
 -		if (candidate.is_bare != -1) {
 -			is_bare_repository_cfg = candidate.is_bare;
 +		if (candidate->is_bare != -1) {
 +			is_bare_repository_cfg = candidate->is_bare;
  			if (is_bare_repository_cfg == 1)
  				inside_work_tree = -1;
  		}
 -		if (candidate.work_tree) {
 +		if (candidate->work_tree) {
  			free(git_work_tree_cfg);
 -			git_work_tree_cfg = candidate.work_tree;
 +			git_work_tree_cfg = candidate->work_tree;
  			inside_work_tree = -1;
  		}
  	} else {
 -		free(candidate.work_tree);
 +		free(candidate->work_tree);
  	}
  
  	return 0;
@@@ -488,7 -492,6 +493,7 @@@ int read_repository_format(struct repos
  	memset(format, 0, sizeof(*format));
  	format->version = -1;
  	format->is_bare = -1;
 +	format->hash_algo = GIT_HASH_SHA1;
  	string_list_init(&format->unknown_extensions, 1);
  	git_config_from_file(check_repo_format, path, format);
  	return format->version;
@@@ -625,7 -628,6 +630,7 @@@ cleanup_return
  
  static const char *setup_explicit_git_dir(const char *gitdirenv,
  					  struct strbuf *cwd,
 +					  struct repository_format *repo_fmt,
  					  int *nongit_ok)
  {
  	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
@@@ -651,7 -653,7 +656,7 @@@
  		die("Not a git repository: '%s'", gitdirenv);
  	}
  
 -	if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 +	if (check_repository_format_gently(gitdirenv, repo_fmt, nongit_ok)) {
  		free(gitfile);
  		return NULL;
  	}
@@@ -724,10 -726,9 +729,10 @@@
  
  static const char *setup_discovered_git_dir(const char *gitdir,
  					    struct strbuf *cwd, int offset,
 +					    struct repository_format *repo_fmt,
  					    int *nongit_ok)
  {
 -	if (check_repository_format_gently(gitdir, nongit_ok))
 +	if (check_repository_format_gently(gitdir, repo_fmt, nongit_ok))
  		return NULL;
  
  	/* --work-tree is set without --git-dir; use discovered one */
@@@ -739,7 -740,7 +744,7 @@@
  			gitdir = to_free = real_pathdup(gitdir, 1);
  		if (chdir(cwd->buf))
  			die_errno("Could not come back to cwd");
 -		ret = setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 +		ret = setup_explicit_git_dir(gitdir, cwd, repo_fmt, nongit_ok);
  		free(to_free);
  		return ret;
  	}
@@@ -771,12 -772,11 +776,12 @@@
  
  /* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
  static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 +				      struct repository_format *repo_fmt,
  				      int *nongit_ok)
  {
  	int root_len;
  
 -	if (check_repository_format_gently(".", nongit_ok))
 +	if (check_repository_format_gently(".", repo_fmt, nongit_ok))
  		return NULL;
  
  	setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
@@@ -788,7 -788,7 +793,7 @@@
  		gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
  		if (chdir(cwd->buf))
  			die_errno("Could not come back to cwd");
 -		return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 +		return setup_explicit_git_dir(gitdir, cwd, repo_fmt, nongit_ok);
  	}
  
  	inside_git_dir = 1;
@@@ -926,7 -926,7 +931,7 @@@ static enum discovery_result setup_git_
  	 * - ../.git
  	 * - ../.git/
  	 * - ../ (bare)
 -	 * - ../../.git/
 +	 * - ../../.git
  	 *   etc.
  	 */
  	one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
@@@ -1029,7 -1029,6 +1034,7 @@@ const char *setup_git_directory_gently(
  	static struct strbuf cwd = STRBUF_INIT;
  	struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT;
  	const char *prefix;
 +	struct repository_format repo_fmt;
  
  	/*
  	 * We may have read an incomplete configuration before
@@@ -1057,18 -1056,18 +1062,18 @@@
  		prefix = NULL;
  		break;
  	case GIT_DIR_EXPLICIT:
 -		prefix = setup_explicit_git_dir(gitdir.buf, &cwd, nongit_ok);
 +		prefix = setup_explicit_git_dir(gitdir.buf, &cwd, &repo_fmt, nongit_ok);
  		break;
  	case GIT_DIR_DISCOVERED:
  		if (dir.len < cwd.len && chdir(dir.buf))
  			die(_("Cannot change to '%s'"), dir.buf);
  		prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len,
 -						  nongit_ok);
 +						  &repo_fmt, nongit_ok);
  		break;
  	case GIT_DIR_BARE:
  		if (dir.len < cwd.len && chdir(dir.buf))
  			die(_("Cannot change to '%s'"), dir.buf);
 -		prefix = setup_bare_git_dir(&cwd, dir.len, nongit_ok);
 +		prefix = setup_bare_git_dir(&cwd, dir.len, &repo_fmt, nongit_ok);
  		break;
  	case GIT_DIR_HIT_CEILING:
  		prefix = setup_nongit(cwd.buf, nongit_ok);
@@@ -1114,8 -1113,6 +1119,8 @@@
  			repo_set_gitdir(the_repository, gitdir);
  			setup_git_env();
  		}
 +		if (startup_info->have_repository)
 +			repo_set_hash_algo(the_repository, repo_fmt.hash_algo);
  	}
  
  	strbuf_release(&dir);
@@@ -1177,8 -1174,7 +1182,8 @@@ int git_config_perm(const char *var, co
  
  void check_repository_format(void)
  {
 -	check_repository_format_gently(get_git_dir(), NULL);
 +	struct repository_format repo_fmt;
 +	check_repository_format_gently(get_git_dir(), &repo_fmt, NULL);
  	startup_info->have_repository = 1;
  }
  
diff --combined sha1_file.c
index 3da70ac650,dd956e2bb6..2e58f5560a
--- a/sha1_file.c
+++ b/sha1_file.c
@@@ -29,6 -29,7 +29,7 @@@
  #include "mergesort.h"
  #include "quote.h"
  #include "packfile.h"
+ #include "fetch-object.h"
  
  const unsigned char null_sha1[GIT_MAX_RAWSZ];
  const struct object_id null_oid;
@@@ -39,64 -40,6 +40,64 @@@ const struct object_id empty_blob_oid 
  	EMPTY_BLOB_SHA1_BIN_LITERAL
  };
  
 +static void git_hash_sha1_init(void *ctx)
 +{
 +	git_SHA1_Init((git_SHA_CTX *)ctx);
 +}
 +
 +static void git_hash_sha1_update(void *ctx, const void *data, size_t len)
 +{
 +	git_SHA1_Update((git_SHA_CTX *)ctx, data, len);
 +}
 +
 +static void git_hash_sha1_final(unsigned char *hash, void *ctx)
 +{
 +	git_SHA1_Final(hash, (git_SHA_CTX *)ctx);
 +}
 +
 +static void git_hash_unknown_init(void *ctx)
 +{
 +	die("trying to init unknown hash");
 +}
 +
 +static void git_hash_unknown_update(void *ctx, const void *data, size_t len)
 +{
 +	die("trying to update unknown hash");
 +}
 +
 +static void git_hash_unknown_final(unsigned char *hash, void *ctx)
 +{
 +	die("trying to finalize unknown hash");
 +}
 +
 +const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
 +	{
 +		NULL,
 +		0x00000000,
 +		0,
 +		0,
 +		0,
 +		git_hash_unknown_init,
 +		git_hash_unknown_update,
 +		git_hash_unknown_final,
 +		NULL,
 +		NULL,
 +	},
 +	{
 +		"sha-1",
 +		/* "sha1", big-endian */
 +		0x73686131,
 +		sizeof(git_SHA_CTX),
 +		GIT_SHA1_RAWSZ,
 +		GIT_SHA1_HEXSZ,
 +		git_hash_sha1_init,
 +		git_hash_sha1_update,
 +		git_hash_sha1_final,
 +		&empty_tree_oid,
 +		&empty_blob_oid,
 +	},
 +};
 +
  /*
   * This is meant to hold a *small* number of objects that you would
   * want read_sha1_file() to be able to return, but yet you do not want
@@@ -132,18 -75,6 +133,18 @@@ static struct cached_object *find_cache
  	return NULL;
  }
  
 +
 +static enum safe_crlf get_safe_crlf(unsigned flags)
 +{
 +	if (flags & HASH_RENORMALIZE)
 +		return SAFE_CRLF_RENORMALIZE;
 +	else if (flags & HASH_WRITE_OBJECT)
 +		return safe_crlf;
 +	else
 +		return SAFE_CRLF_FALSE;
 +}
 +
 +
  int mkdir_in_gitdir(const char *path)
  {
  	if (mkdir(path, 0777)) {
@@@ -474,9 -405,6 +475,9 @@@ static void link_alt_odb_entries(const 
  	struct strbuf objdirbuf = STRBUF_INIT;
  	struct strbuf entry = STRBUF_INIT;
  
 +	if (!alt || !*alt)
 +		return;
 +
  	if (depth > 5) {
  		error("%s: ignoring alternate object stores, nesting too deep.",
  				relative_base);
@@@ -529,19 -457,19 +530,19 @@@ struct alternate_object_database *alloc
  
  void add_to_alternates_file(const char *reference)
  {
 -	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 +	struct lock_file lock = LOCK_INIT;
  	char *alts = git_pathdup("objects/info/alternates");
  	FILE *in, *out;
 +	int found = 0;
  
 -	hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
 -	out = fdopen_lock_file(lock, "w");
 +	hold_lock_file_for_update(&lock, alts, LOCK_DIE_ON_ERROR);
 +	out = fdopen_lock_file(&lock, "w");
  	if (!out)
  		die_errno("unable to fdopen alternates lockfile");
  
  	in = fopen(alts, "r");
  	if (in) {
  		struct strbuf line = STRBUF_INIT;
 -		int found = 0;
  
  		while (strbuf_getline(&line, in) != EOF) {
  			if (!strcmp(reference, line.buf)) {
@@@ -553,15 -481,18 +554,15 @@@
  
  		strbuf_release(&line);
  		fclose(in);
 -
 -		if (found) {
 -			rollback_lock_file(lock);
 -			lock = NULL;
 -		}
  	}
  	else if (errno != ENOENT)
  		die_errno("unable to read alternates file");
  
 -	if (lock) {
 +	if (found) {
 +		rollback_lock_file(&lock);
 +	} else {
  		fprintf_or_die(out, "%s\n", reference);
 -		if (commit_lock_file(lock))
 +		if (commit_lock_file(&lock))
  			die_errno("unable to move new alternates file into place");
  		if (alt_odb_tail)
  			link_alt_odb_entries(reference, '\n', NULL, 0);
@@@ -677,6 -608,7 +678,6 @@@ void prepare_alt_odb(void
  		return;
  
  	alt = getenv(ALTERNATE_DB_ENVIRONMENT);
 -	if (!alt) alt = "";
  
  	alt_odb_tail = &alt_odb_list;
  	link_alt_odb_entries(alt, PATH_SEP, NULL, 0);
@@@ -1213,6 -1145,8 +1214,8 @@@ static int sha1_loose_object_info(cons
  	return (status < 0) ? status : 0;
  }
  
+ int fetch_if_missing = 1;
+ 
  int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
  {
  	static struct object_info blank_oi = OBJECT_INFO_INIT;
@@@ -1221,10 -1155,8 +1224,11 @@@
  	const unsigned char *real = (flags & OBJECT_INFO_LOOKUP_REPLACE) ?
  				    lookup_replace_object(sha1) :
  				    sha1;
+ 	int already_retried = 0;
  
 +	if (is_null_sha1(real))
 +		return -1;
 +
  	if (!oi)
  		oi = &blank_oi;
  
@@@ -1248,19 -1180,32 +1252,32 @@@
  		}
  	}
  
- 	if (!find_pack_entry(real, &e)) {
+ 	while (1) {
+ 		if (find_pack_entry(real, &e))
+ 			break;
+ 
  		/* Most likely it's a loose object. */
  		if (!sha1_loose_object_info(real, oi, flags))
  			return 0;
  
  		/* Not a loose object; someone else may have just packed it. */
- 		if (flags & OBJECT_INFO_QUICK) {
- 			return -1;
- 		} else {
- 			reprepare_packed_git();
- 			if (!find_pack_entry(real, &e))
- 				return -1;
+ 		reprepare_packed_git();
+ 		if (find_pack_entry(real, &e))
+ 			break;
+ 
+ 		/* Check if it is a missing object */
+ 		if (fetch_if_missing && repository_format_partial_clone &&
+ 		    !already_retried) {
+ 			/*
+ 			 * TODO Investigate haveing fetch_object() return
+ 			 * TODO error/success and stopping the music here.
+ 			 */
+ 			fetch_object(repository_format_partial_clone, real);
+ 			already_retried = 1;
+ 			continue;
  		}
+ 
+ 		return -1;
  	}
  
  	if (oi == &blank_oi)
@@@ -1269,7 -1214,6 +1286,6 @@@
  		 * information below, so return early.
  		 */
  		return 0;
- 
  	rtype = packed_object_info(e.p, e.offset, oi);
  	if (rtype < 0) {
  		mark_bad_packed_object(e.p, real);
@@@ -1736,7 -1680,7 +1752,7 @@@ static void check_tag(const void *buf, 
  		die("corrupt tag");
  }
  
 -static int index_mem(unsigned char *sha1, void *buf, size_t size,
 +static int index_mem(struct object_id *oid, void *buf, size_t size,
  		     enum object_type type,
  		     const char *path, unsigned flags)
  {
@@@ -1752,7 -1696,7 +1768,7 @@@
  	if ((type == OBJ_BLOB) && path) {
  		struct strbuf nbuf = STRBUF_INIT;
  		if (convert_to_git(&the_index, path, buf, size, &nbuf,
 -				   write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
 +				   get_safe_crlf(flags))) {
  			buf = strbuf_detach(&nbuf, &size);
  			re_allocated = 1;
  		}
@@@ -1767,15 -1711,15 +1783,15 @@@
  	}
  
  	if (write_object)
 -		ret = write_sha1_file(buf, size, typename(type), sha1);
 +		ret = write_sha1_file(buf, size, typename(type), oid->hash);
  	else
 -		ret = hash_sha1_file(buf, size, typename(type), sha1);
 +		ret = hash_sha1_file(buf, size, typename(type), oid->hash);
  	if (re_allocated)
  		free(buf);
  	return ret;
  }
  
 -static int index_stream_convert_blob(unsigned char *sha1, int fd,
 +static int index_stream_convert_blob(struct object_id *oid, int fd,
  				     const char *path, unsigned flags)
  {
  	int ret;
@@@ -1786,26 -1730,26 +1802,26 @@@
  	assert(would_convert_to_git_filter_fd(path));
  
  	convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
 -				 write_object ? safe_crlf : SAFE_CRLF_FALSE);
 +				 get_safe_crlf(flags));
  
  	if (write_object)
  		ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
 -				      sha1);
 +				      oid->hash);
  	else
  		ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
 -				     sha1);
 +				     oid->hash);
  	strbuf_release(&sbuf);
  	return ret;
  }
  
 -static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
 +static int index_pipe(struct object_id *oid, int fd, enum object_type type,
  		      const char *path, unsigned flags)
  {
  	struct strbuf sbuf = STRBUF_INIT;
  	int ret;
  
  	if (strbuf_read(&sbuf, fd, 4096) >= 0)
 -		ret = index_mem(sha1, sbuf.buf, sbuf.len, type,	path, flags);
 +		ret = index_mem(oid, sbuf.buf, sbuf.len, type, path, flags);
  	else
  		ret = -1;
  	strbuf_release(&sbuf);
@@@ -1814,14 -1758,14 +1830,14 @@@
  
  #define SMALL_FILE_SIZE (32*1024)
  
 -static int index_core(unsigned char *sha1, int fd, size_t size,
 +static int index_core(struct object_id *oid, int fd, size_t size,
  		      enum object_type type, const char *path,
  		      unsigned flags)
  {
  	int ret;
  
  	if (!size) {
 -		ret = index_mem(sha1, "", size, type, path, flags);
 +		ret = index_mem(oid, "", size, type, path, flags);
  	} else if (size <= SMALL_FILE_SIZE) {
  		char *buf = xmalloc(size);
  		ssize_t read_result = read_in_full(fd, buf, size);
@@@ -1832,11 -1776,11 +1848,11 @@@
  			ret = error("short read while indexing %s",
  				    path ? path : "<unknown>");
  		else
 -			ret = index_mem(sha1, buf, size, type, path, flags);
 +			ret = index_mem(oid, buf, size, type, path, flags);
  		free(buf);
  	} else {
  		void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
 -		ret = index_mem(sha1, buf, size, type, path, flags);
 +		ret = index_mem(oid, buf, size, type, path, flags);
  		munmap(buf, size);
  	}
  	return ret;
@@@ -1874,12 -1818,12 +1890,12 @@@ int index_fd(struct object_id *oid, in
  	 * die() for large files.
  	 */
  	if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
 -		ret = index_stream_convert_blob(oid->hash, fd, path, flags);
 +		ret = index_stream_convert_blob(oid, fd, path, flags);
  	else if (!S_ISREG(st->st_mode))
 -		ret = index_pipe(oid->hash, fd, type, path, flags);
 +		ret = index_pipe(oid, fd, type, path, flags);
  	else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
  		 (path && would_convert_to_git(&the_index, path)))
 -		ret = index_core(oid->hash, fd, xsize_t(st->st_size), type, path,
 +		ret = index_core(oid, fd, xsize_t(st->st_size), type, path,
  				 flags);
  	else
  		ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
@@@ -1913,7 -1857,7 +1929,7 @@@ int index_path(struct object_id *oid, c
  		strbuf_release(&sb);
  		break;
  	case S_IFDIR:
 -		return resolve_gitlink_ref(path, "HEAD", oid->hash);
 +		return resolve_gitlink_ref(path, "HEAD", oid);
  	default:
  		return error("%s: unsupported file type", path);
  	}
@@@ -1956,7 -1900,6 +1972,7 @@@ int for_each_file_in_obj_subdir(unsigne
  	DIR *dir;
  	struct dirent *de;
  	int r = 0;
 +	struct object_id oid;
  
  	if (subdir_nr > 0xff)
  		BUG("invalid loose object subdirectory: %x", subdir_nr);
@@@ -1964,6 -1907,7 +1980,6 @@@
  	origlen = path->len;
  	strbuf_complete(path, '/');
  	strbuf_addf(path, "%02x", subdir_nr);
 -	baselen = path->len;
  
  	dir = opendir(path->buf);
  	if (!dir) {
@@@ -1973,27 -1917,27 +1989,27 @@@
  		return r;
  	}
  
 +	oid.hash[0] = subdir_nr;
 +	strbuf_addch(path, '/');
 +	baselen = path->len;
 +
  	while ((de = readdir(dir))) {
 +		size_t namelen;
  		if (is_dot_or_dotdot(de->d_name))
  			continue;
  
 +		namelen = strlen(de->d_name);
  		strbuf_setlen(path, baselen);
 -		strbuf_addf(path, "/%s", de->d_name);
 -
 -		if (strlen(de->d_name) == GIT_SHA1_HEXSZ - 2)  {
 -			char hex[GIT_MAX_HEXSZ+1];
 -			struct object_id oid;
 -
 -			xsnprintf(hex, sizeof(hex), "%02x%s",
 -				  subdir_nr, de->d_name);
 -			if (!get_oid_hex(hex, &oid)) {
 -				if (obj_cb) {
 -					r = obj_cb(&oid, path->buf, data);
 -					if (r)
 -						break;
 -				}
 -				continue;
 +		strbuf_add(path, de->d_name, namelen);
 +		if (namelen == GIT_SHA1_HEXSZ - 2 &&
 +		    !hex_to_bytes(oid.hash + 1, de->d_name,
 +				  GIT_SHA1_RAWSZ - 1)) {
 +			if (obj_cb) {
 +				r = obj_cb(&oid, path->buf, data);
 +				if (r)
 +					break;
  			}
 +			continue;
  		}
  
  		if (cruft_cb) {
@@@ -2004,7 -1948,7 +2020,7 @@@
  	}
  	closedir(dir);
  
 -	strbuf_setlen(path, baselen);
 +	strbuf_setlen(path, baselen - 1);
  	if (!r && subdir_cb)
  		r = subdir_cb(subdir_nr, path->buf, data);
  
diff --combined transport.c
index fc802260f6,f2fbc6f968..e82db773fd
--- a/transport.c
+++ b/transport.c
@@@ -17,7 -17,6 +17,7 @@@
  #include "string-list.h"
  #include "sha1-array.h"
  #include "sigchain.h"
 +#include "transport-internal.h"
  
  static void set_upstreams(struct transport *transport, struct ref *refs,
  	int pretend)
@@@ -161,6 -160,12 +161,12 @@@ static int set_git_option(struct git_tr
  	} else if (!strcmp(name, TRANS_OPT_DEEPEN_RELATIVE)) {
  		opts->deepen_relative = !!value;
  		return 0;
+ 	} else if (!strcmp(name, TRANS_OPT_FROM_PROMISOR)) {
+ 		opts->from_promisor = !!value;
+ 		return 0;
+ 	} else if (!strcmp(name, TRANS_OPT_NO_DEPENDENTS)) {
+ 		opts->no_dependents = !!value;
+ 		return 0;
  	}
  	return 1;
  }
@@@ -229,6 -234,8 +235,8 @@@ static int fetch_refs_via_pack(struct t
  		data->options.check_self_contained_and_connected;
  	args.cloning = transport->cloning;
  	args.update_shallow = data->options.update_shallow;
+ 	args.from_promisor = data->options.from_promisor;
+ 	args.no_dependents = data->options.no_dependents;
  
  	if (!data->got_remote_heads) {
  		connect_setup(transport, 0);
@@@ -306,8 -313,8 +314,8 @@@ void transport_update_tracking_ref(stru
  		if (ref->deletion) {
  			delete_ref(NULL, rs.dst, NULL, 0);
  		} else
 -			update_ref("update by push", rs.dst,
 -					ref->new_oid.hash, NULL, 0, 0);
 +			update_ref("update by push", rs.dst, &ref->new_oid,
 +				   NULL, 0, 0);
  		free(rs.dst);
  	}
  }
@@@ -608,15 -615,6 +616,15 @@@ static int disconnect_git(struct transp
  	return 0;
  }
  
 +static struct transport_vtable taken_over_vtable = {
 +	NULL,
 +	get_refs_via_connect,
 +	fetch_refs_via_pack,
 +	git_transport_push,
 +	NULL,
 +	disconnect_git
 +};
 +
  void transport_take_over(struct transport *transport,
  			 struct child_process *child)
  {
@@@ -634,7 -632,12 +642,7 @@@
  	data->got_remote_heads = 0;
  	transport->data = data;
  
 -	transport->set_option = NULL;
 -	transport->get_refs_list = get_refs_via_connect;
 -	transport->fetch = fetch_refs_via_pack;
 -	transport->push = NULL;
 -	transport->push_refs = git_transport_push;
 -	transport->disconnect = disconnect_git;
 +	transport->vtable = &taken_over_vtable;
  	transport->smart_options = &(data->options);
  
  	transport->cannot_reuse = 1;
@@@ -757,24 -760,6 +765,24 @@@ void transport_check_allowed(const cha
  		die("transport '%s' not allowed", type);
  }
  
 +static struct transport_vtable bundle_vtable = {
 +	NULL,
 +	get_refs_from_bundle,
 +	fetch_refs_from_bundle,
 +	NULL,
 +	NULL,
 +	close_bundle
 +};
 +
 +static struct transport_vtable builtin_smart_vtable = {
 +	NULL,
 +	get_refs_via_connect,
 +	fetch_refs_via_pack,
 +	git_transport_push,
 +	connect_git,
 +	disconnect_git
 +};
 +
  struct transport *transport_get(struct remote *remote, const char *url)
  {
  	const char *helper;
@@@ -811,7 -796,9 +819,7 @@@
  		struct bundle_transport_data *data = xcalloc(1, sizeof(*data));
  		transport_check_allowed("file");
  		ret->data = data;
 -		ret->get_refs_list = get_refs_from_bundle;
 -		ret->fetch = fetch_refs_from_bundle;
 -		ret->disconnect = close_bundle;
 +		ret->vtable = &bundle_vtable;
  		ret->smart_options = NULL;
  	} else if (!is_url(url)
  		|| starts_with(url, "file://")
@@@ -826,7 -813,12 +834,7 @@@
  		 */
  		struct git_transport_data *data = xcalloc(1, sizeof(*data));
  		ret->data = data;
 -		ret->set_option = NULL;
 -		ret->get_refs_list = get_refs_via_connect;
 -		ret->fetch = fetch_refs_via_pack;
 -		ret->push_refs = git_transport_push;
 -		ret->connect = connect_git;
 -		ret->disconnect = disconnect_git;
 +		ret->vtable = &builtin_smart_vtable;
  		ret->smart_options = &(data->options);
  
  		data->conn = NULL;
@@@ -860,9 -852,9 +868,9 @@@ int transport_set_option(struct transpo
  		git_reports = set_git_option(transport->smart_options,
  					     name, value);
  
 -	if (transport->set_option)
 -		protocol_reports = transport->set_option(transport, name,
 -							value);
 +	if (transport->vtable->set_option)
 +		protocol_reports = transport->vtable->set_option(transport,
 +								 name, value);
  
  	/* If either report is 0, report 0 (success). */
  	if (!git_reports || !protocol_reports)
@@@ -985,7 -977,13 +993,7 @@@ int transport_push(struct transport *tr
  	*reject_reasons = 0;
  	transport_verify_remote_names(refspec_nr, refspec);
  
 -	if (transport->push) {
 -		/* Maybe FIXME. But no important transport uses this case. */
 -		if (flags & TRANSPORT_PUSH_SET_UPSTREAM)
 -			die("This transport does not support using --set-upstream");
 -
 -		return transport->push(transport, refspec_nr, refspec, flags);
 -	} else if (transport->push_refs) {
 +	if (transport->vtable->push_refs) {
  		struct ref *remote_refs;
  		struct ref *local_refs = get_local_heads();
  		int match_flags = MATCH_REFS_NONE;
@@@ -998,7 -996,7 +1006,7 @@@
  		if (check_push_refs(local_refs, refspec_nr, refspec) < 0)
  			return -1;
  
 -		remote_refs = transport->get_refs_list(transport, 1);
 +		remote_refs = transport->vtable->get_refs_list(transport, 1);
  
  		if (flags & TRANSPORT_PUSH_ALL)
  			match_flags |= MATCH_REFS_ALL;
@@@ -1073,7 -1071,7 +1081,7 @@@
  		}
  
  		if (!(flags & TRANSPORT_RECURSE_SUBMODULES_ONLY))
 -			push_ret = transport->push_refs(transport, remote_refs, flags);
 +			push_ret = transport->vtable->push_refs(transport, remote_refs, flags);
  		else
  			push_ret = 0;
  		err = push_had_errors(remote_refs);
@@@ -1107,7 -1105,7 +1115,7 @@@
  const struct ref *transport_get_remote_refs(struct transport *transport)
  {
  	if (!transport->got_remote_refs) {
 -		transport->remote_refs = transport->get_refs_list(transport, 0);
 +		transport->remote_refs = transport->vtable->get_refs_list(transport, 0);
  		transport->got_remote_refs = 1;
  	}
  
@@@ -1144,7 -1142,7 +1152,7 @@@ int transport_fetch_refs(struct transpo
  			heads[nr_heads++] = rm;
  	}
  
 -	rc = transport->fetch(transport, nr_heads, heads);
 +	rc = transport->vtable->fetch(transport, nr_heads, heads);
  
  	free(heads);
  	return rc;
@@@ -1161,8 -1159,8 +1169,8 @@@ void transport_unlock_pack(struct trans
  int transport_connect(struct transport *transport, const char *name,
  		      const char *exec, int fd[2])
  {
 -	if (transport->connect)
 -		return transport->connect(transport, name, exec, fd);
 +	if (transport->vtable->connect)
 +		return transport->vtable->connect(transport, name, exec, fd);
  	else
  		die("Operation not supported by protocol");
  }
@@@ -1170,8 -1168,8 +1178,8 @@@
  int transport_disconnect(struct transport *transport)
  {
  	int ret = 0;
 -	if (transport->disconnect)
 -		ret = transport->disconnect(transport);
 +	if (transport->vtable->disconnect)
 +		ret = transport->vtable->disconnect(transport);
  	free(transport);
  	return ret;
  }
diff --combined transport.h
index 731c78b679,c49a8edc53..8c3430a5b9
--- a/transport.h
+++ b/transport.h
@@@ -15,6 -15,8 +15,8 @@@ struct git_transport_options 
  	unsigned self_contained_and_connected : 1;
  	unsigned update_shallow : 1;
  	unsigned deepen_relative : 1;
+ 	unsigned from_promisor : 1;
+ 	unsigned no_dependents : 1;
  	int depth;
  	const char *deepen_since;
  	const struct string_list *deepen_not;
@@@ -30,8 -32,6 +32,8 @@@ enum transport_family 
  };
  
  struct transport {
 +	const struct transport_vtable *vtable;
 +
  	struct remote *remote;
  	const char *url;
  	void *data;
@@@ -61,6 -61,59 +63,6 @@@
  	 */
  	const struct string_list *push_options;
  
 -	/**
 -	 * Returns 0 if successful, positive if the option is not
 -	 * recognized or is inapplicable, and negative if the option
 -	 * is applicable but the value is invalid.
 -	 **/
 -	int (*set_option)(struct transport *connection, const char *name,
 -			  const char *value);
 -
 -	/**
 -	 * Returns a list of the remote side's refs. In order to allow
 -	 * the transport to try to share connections, for_push is a
 -	 * hint as to whether the ultimate operation is a push or a fetch.
 -	 *
 -	 * If the transport is able to determine the remote hash for
 -	 * the ref without a huge amount of effort, it should store it
 -	 * in the ref's old_sha1 field; otherwise it should be all 0.
 -	 **/
 -	struct ref *(*get_refs_list)(struct transport *transport, int for_push);
 -
 -	/**
 -	 * Fetch the objects for the given refs. Note that this gets
 -	 * an array, and should ignore the list structure.
 -	 *
 -	 * If the transport did not get hashes for refs in
 -	 * get_refs_list(), it should set the old_sha1 fields in the
 -	 * provided refs now.
 -	 **/
 -	int (*fetch)(struct transport *transport, int refs_nr, struct ref **refs);
 -
 -	/**
 -	 * Push the objects and refs. Send the necessary objects, and
 -	 * then, for any refs where peer_ref is set and
 -	 * peer_ref->new_oid is different from old_oid, tell the
 -	 * remote side to update each ref in the list from old_oid to
 -	 * peer_ref->new_oid.
 -	 *
 -	 * Where possible, set the status for each ref appropriately.
 -	 *
 -	 * The transport must modify new_sha1 in the ref to the new
 -	 * value if the remote accepted the change. Note that this
 -	 * could be a different value from peer_ref->new_oid if the
 -	 * process involved generating new commits.
 -	 **/
 -	int (*push_refs)(struct transport *transport, struct ref *refs, int flags);
 -	int (*push)(struct transport *connection, int refspec_nr, const char **refspec, int flags);
 -	int (*connect)(struct transport *connection, const char *name,
 -		       const char *executable, int fd[2]);
 -
 -	/** get_refs_list(), fetch(), and push_refs() can keep
 -	 * resources (such as a connection) reserved for further
 -	 * use. disconnect() releases these resources.
 -	 **/
 -	int (*disconnect)(struct transport *connection);
  	char *pack_lockfile;
  	signed verbose : 3;
  	/**
@@@ -159,6 -212,15 +161,15 @@@ void transport_check_allowed(const cha
  /* Send push certificates */
  #define TRANS_OPT_PUSH_CERT "pushcert"
  
+ /* Indicate that these objects are being fetched by a promisor */
+ #define TRANS_OPT_FROM_PROMISOR "from-promisor"
+ 
+ /*
+  * Indicate that only the objects wanted need to be fetched, not their
+  * dependents
+  */
+ #define TRANS_OPT_NO_DEPENDENTS "no-dependents"
+ 
  /**
   * Returns 0 if the option was used, non-zero otherwise. Prints a
   * message to stderr if the option is not used.