diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index 0cd87dd..6ebd512 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -45,7 +45,11 @@
 branch).
 
 The command's second form creates a new branch head named <branchname>
-which points to the current `HEAD`, or <start-point> if given.
+which points to the current `HEAD`, or <start-point> if given. As a
+special case, for <start-point>, you may use `"A...B"` as a shortcut for
+the merge base of `A` and `B` if there is exactly one merge base. You
+can leave out at most one of `A` and `B`, in which case it defaults to
+`HEAD`.
 
 Note that this will create the new branch, but it will not switch the
 working tree to it; use "git checkout <newbranch>" to switch to the
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 877e5f5..964f912 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -313,6 +313,10 @@
 <start_point>::
 	The name of a commit at which to start the new branch; see
 	linkgit:git-branch[1] for details. Defaults to HEAD.
++
+As a special case, you may use `"A...B"` as a shortcut for the
+merge base of `A` and `B` if there is exactly one merge base. You can
+leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 
 <tree-ish>::
 	Tree to checkout from (when paths are given). If not specified,
diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 96c26e6..484c485 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -90,7 +90,9 @@
 	When 'git-difftool' is invoked with the `-g` or `--gui` option
 	the default diff tool will be read from the configured
 	`diff.guitool` variable instead of `diff.tool`. The `--no-gui`
-	option can be used to override this setting.
+	option can be used to override this setting. If `diff.guitool`
+	is not set, we will fallback in the order of `merge.guitool`,
+	`diff.tool`, `merge.tool` until a tool is found.
 
 --[no-]trust-exit-code::
 	'git-difftool' invokes a diff tool individually on each file.
diff --git a/Documentation/git-mergetool--lib.txt b/Documentation/git-mergetool--lib.txt
index 055550b..4da9d24 100644
--- a/Documentation/git-mergetool--lib.txt
+++ b/Documentation/git-mergetool--lib.txt
@@ -28,7 +28,9 @@
 FUNCTIONS
 ---------
 get_merge_tool::
-	returns a merge tool.
+	returns a merge tool. the return code is 1 if we returned a guessed
+	merge tool, else 0. '$GIT_MERGETOOL_GUI' may be set to 'true' to
+	search for the appropriate guitool.
 
 get_merge_tool_cmd::
 	returns the custom command for a merge tool.
diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index 0c7975a..6b14702 100644
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -83,7 +83,9 @@
 --gui::
 	When 'git-mergetool' is invoked with the `-g` or `--gui` option
 	the default merge tool will be read from the configured
-	`merge.guitool` variable instead of `merge.tool`.
+	`merge.guitool` variable instead of `merge.tool`. If
+	`merge.guitool` is not set, we will fallback to the tool
+	configured under `merge.tool`.
 
 --no-gui::
 	This overrides a previous `-g` or `--gui` setting and reads the
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 6d1f2fd..72adfcc 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -660,6 +660,27 @@
 	When a curl trace is enabled (see `GIT_TRACE_CURL` above), do not dump
 	data (that is, only dump info lines and headers).
 
+`GIT_TR2`::
+	Enables more detailed trace messages from the "trace2" library.
+	Output from `GIT_TR2` is a simple text-based format for human
+	readability.
++
+The `GIT_TR2` variables can take many values. Any value available to
+the `GIT_TRACE` variables is also available to `GIT_TR2`. The `GIT_TR2`
+variables can also specify a Unix Domain Socket. See
+link:technical/api-trace2.html[Trace2 documentation] for full details.
+
+`GIT_TR2_EVENT`::
+	This setting writes a JSON-based format that is suited for machine
+	interpretation. See link:technical/api-trace2.html[Trace2 documentation]
+	for full details.
+
+`GIT_TR2_PERF`::
+	In addition to the text-based messages available in `GIT_TR2`, this
+	setting writes a column-based format for understanding nesting
+	regions. See link:technical/api-trace2.html[Trace2 documentation]
+	for full details.
+
 `GIT_REDACT_COOKIES`::
 	This can be set to a comma-separated list of strings. When a curl trace
 	is enabled (see `GIT_TRACE_CURL` above), whenever a "Cookies:" header
diff --git a/Makefile b/Makefile
index f965509..8a7e235 100644
--- a/Makefile
+++ b/Makefile
@@ -1171,8 +1171,11 @@
 SPARSE_FLAGS ?=
 SP_EXTRA_FLAGS =
 
-# For the 'coccicheck' target
+# For the 'coccicheck' target; setting SPATCH_BATCH_SIZE higher will
+# usually result in less CPU usage at the cost of higher peak memory.
+# Setting it to 0 will feed all files in a single spatch invocation.
 SPATCH_FLAGS = --all-includes --patch .
+SPATCH_BATCH_SIZE = 1
 
 include config.mak.uname
 -include config.mak.autogen
@@ -2807,12 +2810,14 @@
 
 %.cocci.patch: %.cocci $(COCCI_SOURCES)
 	@echo '    ' SPATCH $<; \
-	ret=0; \
-	for f in $(COCCI_SOURCES); do \
-		$(SPATCH) --sp-file $< $$f $(SPATCH_FLAGS) || \
-			{ ret=$$?; break; }; \
-	done >$@+ 2>$@.log; \
-	if test $$ret != 0; \
+	if test $(SPATCH_BATCH_SIZE) = 0; then \
+		limit=; \
+	else \
+		limit='-n $(SPATCH_BATCH_SIZE)'; \
+	fi; \
+	if ! echo $(COCCI_SOURCES) | xargs $$limit \
+		$(SPATCH) --sp-file $< $(SPATCH_FLAGS) \
+		>$@+ 2>$@.log; \
 	then \
 		cat $@.log; \
 		exit 1; \
diff --git a/branch.c b/branch.c
index 6436945..a594cc2 100644
--- a/branch.c
+++ b/branch.c
@@ -269,7 +269,7 @@
 	}
 
 	real_ref = NULL;
-	if (get_oid(start_name, &oid)) {
+	if (get_oid_mb(start_name, &oid)) {
 		if (explicit_tracking) {
 			if (advice_set_upstream_failure) {
 				error(_(upstream_missing), start_name);
diff --git a/builtin/clone.c b/builtin/clone.c
index ffdd94e..85b0d31 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -99,10 +99,7 @@
 		    N_("don't use local hardlinks, always copy")),
 	OPT_BOOL('s', "shared", &option_shared,
 		    N_("setup as shared repository")),
-	{ OPTION_CALLBACK, 0, "recursive", &option_recurse_submodules,
-	  N_("pathspec"), N_("initialize submodules in the clone"),
-	  PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, recurse_submodules_cb,
-	  (intptr_t)"." },
+	OPT_ALIAS(0, "recursive", "recurse-submodules"),
 	{ OPTION_CALLBACK, 0, "recurse-submodules", &option_recurse_submodules,
 	  N_("pathspec"), N_("initialize submodules in the clone"),
 	  PARSE_OPT_OPTARG, recurse_submodules_cb, (intptr_t)"." },
diff --git a/builtin/difftool.c b/builtin/difftool.c
index 04ffa1d..53188df 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -24,7 +24,6 @@
 #include "object-store.h"
 #include "dir.h"
 
-static char *diff_gui_tool;
 static int trust_exit_code;
 
 static const char *const builtin_difftool_usage[] = {
@@ -34,11 +33,6 @@
 
 static int difftool_config(const char *var, const char *value, void *cb)
 {
-	if (!strcmp(var, "diff.guitool")) {
-		diff_gui_tool = xstrdup(value);
-		return 0;
-	}
-
 	if (!strcmp(var, "difftool.trustexitcode")) {
 		trust_exit_code = git_config_bool(var, value);
 		return 0;
@@ -735,8 +729,11 @@
 		setenv(GIT_WORK_TREE_ENVIRONMENT, absolute_path(get_git_work_tree()), 1);
 	}
 
-	if (use_gui_tool && diff_gui_tool && *diff_gui_tool)
-		setenv("GIT_DIFF_TOOL", diff_gui_tool, 1);
+	if (use_gui_tool + !!difftool_cmd + !!extcmd > 1)
+		die(_("--gui, --tool and --extcmd are mutually exclusive"));
+
+	if (use_gui_tool)
+		setenv("GIT_MERGETOOL_GUI", "true", 1);
 	else if (difftool_cmd) {
 		if (*difftool_cmd)
 			setenv("GIT_DIFF_TOOL", difftool_cmd, 1);
diff --git a/builtin/multi-pack-index.c b/builtin/multi-pack-index.c
index ae6e476..72dfd3d 100644
--- a/builtin/multi-pack-index.c
+++ b/builtin/multi-pack-index.c
@@ -46,7 +46,7 @@
 	if (!strcmp(argv[0], "write"))
 		return write_midx_file(opts.object_dir);
 	if (!strcmp(argv[0], "verify"))
-		return verify_midx_file(opts.object_dir);
+		return verify_midx_file(the_repository, opts.object_dir);
 
 	die(_("unrecognized verb: %s"), argv[0]);
 }
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 9f424aa..41d7fc5 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1080,7 +1080,7 @@
 
 	for (m = get_multi_pack_index(the_repository); m; m = m->next) {
 		struct pack_entry e;
-		if (fill_midx_entry(oid, &e, m)) {
+		if (fill_midx_entry(the_repository, oid, &e, m)) {
 			struct packed_git *p = e.p;
 			off_t offset;
 
diff --git a/builtin/pack-refs.c b/builtin/pack-refs.c
index f335356..cfbd5c3 100644
--- a/builtin/pack-refs.c
+++ b/builtin/pack-refs.c
@@ -1,4 +1,5 @@
 #include "builtin.h"
+#include "config.h"
 #include "parse-options.h"
 #include "refs.h"
 #include "repository.h"
@@ -16,6 +17,7 @@
 		OPT_BIT(0, "prune", &flags, N_("prune loose refs (default)"), PACK_REFS_PRUNE),
 		OPT_END(),
 	};
+	git_config(git_default_config, NULL);
 	if (parse_options(argc, argv, prefix, opts, pack_refs_usage, 0))
 		usage_with_options(pack_refs_usage, opts);
 	return refs_pack_refs(get_main_ref_store(the_repository), flags);
diff --git a/builtin/show-ref.c b/builtin/show-ref.c
index 6a706c0..6456da7 100644
--- a/builtin/show-ref.c
+++ b/builtin/show-ref.c
@@ -1,5 +1,6 @@
 #include "builtin.h"
 #include "cache.h"
+#include "config.h"
 #include "refs.h"
 #include "object-store.h"
 #include "object.h"
@@ -182,6 +183,8 @@
 
 int cmd_show_ref(int argc, const char **argv, const char *prefix)
 {
+	git_config(git_default_config, NULL);
+
 	argc = parse_options(argc, argv, prefix, show_ref_options,
 			     show_ref_usage, 0);
 
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 8c72ea8..0bf4aa0 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1301,7 +1301,7 @@
 				die(_("submodule '%s' cannot add alternate: %s"),
 				    sas->submodule_name, err.buf);
 			case SUBMODULE_ALTERNATE_ERROR_INFO:
-				fprintf(stderr, _("submodule '%s' cannot add alternate: %s"),
+				fprintf_ln(stderr, _("submodule '%s' cannot add alternate: %s"),
 					sas->submodule_name, err.buf);
 			case SUBMODULE_ALTERNATE_ERROR_IGNORE:
 				; /* nothing */
diff --git a/builtin/tag.c b/builtin/tag.c
index 1debd3a..ef37dcc 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -207,7 +207,7 @@
 };
 
 static const char message_advice_nested_tag[] =
-	N_("You have created a nested tag. The object referred to by your new is\n"
+	N_("You have created a nested tag. The object referred to by your new tag is\n"
 	   "already a tag. If you meant to tag the object that it points to, use:\n"
 	   "\n"
 	   "\tgit tag -f %s %s^{}");
diff --git a/cache.h b/cache.h
index fa8ede9..b4bb2e2 100644
--- a/cache.h
+++ b/cache.h
@@ -341,7 +341,8 @@
 		 initialized : 1,
 		 drop_cache_tree : 1,
 		 updated_workdir : 1,
-		 updated_skipworktree : 1;
+		 updated_skipworktree : 1,
+		 fsmonitor_has_run_once : 1;
 	struct hashmap name_hash;
 	struct hashmap dir_hash;
 	struct object_id oid;
diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
index 52a44c6..7f6acdd 100755
--- a/ci/install-dependencies.sh
+++ b/ci/install-dependencies.sh
@@ -12,7 +12,7 @@
 linux-clang|linux-gcc)
 	sudo apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
 	sudo apt-get -q update
-	sudo apt-get -q -y install language-pack-is git-svn apache2
+	sudo apt-get -q -y install language-pack-is libsvn-perl apache2
 	case "$jobname" in
 	linux-gcc)
 		sudo apt-get -q -y install gcc-8
diff --git a/commit-graph.c b/commit-graph.c
index 7bcc9bb..7c5e548 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -267,8 +267,10 @@
 		last_chunk_offset = chunk_offset;
 	}
 
-	if (verify_commit_graph_lite(graph))
+	if (verify_commit_graph_lite(graph)) {
+		free(graph);
 		return NULL;
+	}
 
 	return graph;
 }
diff --git a/compat/mingw.c b/compat/mingw.c
index a2f74ac..9b6d240 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1714,142 +1714,10 @@
 	return result ? 0 : -1;
 }
 
-/*
- * Note, this isn't a complete replacement for getaddrinfo. It assumes
- * that service contains a numerical port, or that it is null. It
- * does a simple search using gethostbyname, and returns one IPv4 host
- * if one was found.
- */
-static int WSAAPI getaddrinfo_stub(const char *node, const char *service,
-				   const struct addrinfo *hints,
-				   struct addrinfo **res)
-{
-	struct hostent *h = NULL;
-	struct addrinfo *ai;
-	struct sockaddr_in *sin;
-
-	if (node) {
-		h = gethostbyname(node);
-		if (!h)
-			return WSAGetLastError();
-	}
-
-	ai = xmalloc(sizeof(struct addrinfo));
-	*res = ai;
-	ai->ai_flags = 0;
-	ai->ai_family = AF_INET;
-	ai->ai_socktype = hints ? hints->ai_socktype : 0;
-	switch (ai->ai_socktype) {
-	case SOCK_STREAM:
-		ai->ai_protocol = IPPROTO_TCP;
-		break;
-	case SOCK_DGRAM:
-		ai->ai_protocol = IPPROTO_UDP;
-		break;
-	default:
-		ai->ai_protocol = 0;
-		break;
-	}
-	ai->ai_addrlen = sizeof(struct sockaddr_in);
-	if (hints && (hints->ai_flags & AI_CANONNAME))
-		ai->ai_canonname = h ? xstrdup(h->h_name) : NULL;
-	else
-		ai->ai_canonname = NULL;
-
-	sin = xcalloc(1, ai->ai_addrlen);
-	sin->sin_family = AF_INET;
-	/* Note: getaddrinfo is supposed to allow service to be a string,
-	 * which should be looked up using getservbyname. This is
-	 * currently not implemented */
-	if (service)
-		sin->sin_port = htons(atoi(service));
-	if (h)
-		sin->sin_addr = *(struct in_addr *)h->h_addr;
-	else if (hints && (hints->ai_flags & AI_PASSIVE))
-		sin->sin_addr.s_addr = INADDR_ANY;
-	else
-		sin->sin_addr.s_addr = INADDR_LOOPBACK;
-	ai->ai_addr = (struct sockaddr *)sin;
-	ai->ai_next = NULL;
-	return 0;
-}
-
-static void WSAAPI freeaddrinfo_stub(struct addrinfo *res)
-{
-	free(res->ai_canonname);
-	free(res->ai_addr);
-	free(res);
-}
-
-static int WSAAPI getnameinfo_stub(const struct sockaddr *sa, socklen_t salen,
-				   char *host, DWORD hostlen,
-				   char *serv, DWORD servlen, int flags)
-{
-	const struct sockaddr_in *sin = (const struct sockaddr_in *)sa;
-	if (sa->sa_family != AF_INET)
-		return EAI_FAMILY;
-	if (!host && !serv)
-		return EAI_NONAME;
-
-	if (host && hostlen > 0) {
-		struct hostent *ent = NULL;
-		if (!(flags & NI_NUMERICHOST))
-			ent = gethostbyaddr((const char *)&sin->sin_addr,
-					    sizeof(sin->sin_addr), AF_INET);
-
-		if (ent)
-			snprintf(host, hostlen, "%s", ent->h_name);
-		else if (flags & NI_NAMEREQD)
-			return EAI_NONAME;
-		else
-			snprintf(host, hostlen, "%s", inet_ntoa(sin->sin_addr));
-	}
-
-	if (serv && servlen > 0) {
-		struct servent *ent = NULL;
-		if (!(flags & NI_NUMERICSERV))
-			ent = getservbyport(sin->sin_port,
-					    flags & NI_DGRAM ? "udp" : "tcp");
-
-		if (ent)
-			snprintf(serv, servlen, "%s", ent->s_name);
-		else
-			snprintf(serv, servlen, "%d", ntohs(sin->sin_port));
-	}
-
-	return 0;
-}
-
-static HMODULE ipv6_dll = NULL;
-static void (WSAAPI *ipv6_freeaddrinfo)(struct addrinfo *res);
-static int (WSAAPI *ipv6_getaddrinfo)(const char *node, const char *service,
-				      const struct addrinfo *hints,
-				      struct addrinfo **res);
-static int (WSAAPI *ipv6_getnameinfo)(const struct sockaddr *sa, socklen_t salen,
-				      char *host, DWORD hostlen,
-				      char *serv, DWORD servlen, int flags);
-/*
- * gai_strerror is an inline function in the ws2tcpip.h header, so we
- * don't need to try to load that one dynamically.
- */
-
-static void socket_cleanup(void)
-{
-	WSACleanup();
-	if (ipv6_dll)
-		FreeLibrary(ipv6_dll);
-	ipv6_dll = NULL;
-	ipv6_freeaddrinfo = freeaddrinfo_stub;
-	ipv6_getaddrinfo = getaddrinfo_stub;
-	ipv6_getnameinfo = getnameinfo_stub;
-}
-
 static void ensure_socket_initialization(void)
 {
 	WSADATA wsa;
 	static int initialized = 0;
-	const char *libraries[] = { "ws2_32.dll", "wship6.dll", NULL };
-	const char **name;
 
 	if (initialized)
 		return;
@@ -1858,35 +1726,7 @@
 		die("unable to initialize winsock subsystem, error %d",
 			WSAGetLastError());
 
-	for (name = libraries; *name; name++) {
-		ipv6_dll = LoadLibraryExA(*name, NULL,
-					  LOAD_LIBRARY_SEARCH_SYSTEM32);
-		if (!ipv6_dll)
-			continue;
-
-		ipv6_freeaddrinfo = (void (WSAAPI *)(struct addrinfo *))
-			GetProcAddress(ipv6_dll, "freeaddrinfo");
-		ipv6_getaddrinfo = (int (WSAAPI *)(const char *, const char *,
-						   const struct addrinfo *,
-						   struct addrinfo **))
-			GetProcAddress(ipv6_dll, "getaddrinfo");
-		ipv6_getnameinfo = (int (WSAAPI *)(const struct sockaddr *,
-						   socklen_t, char *, DWORD,
-						   char *, DWORD, int))
-			GetProcAddress(ipv6_dll, "getnameinfo");
-		if (!ipv6_freeaddrinfo || !ipv6_getaddrinfo || !ipv6_getnameinfo) {
-			FreeLibrary(ipv6_dll);
-			ipv6_dll = NULL;
-		} else
-			break;
-	}
-	if (!ipv6_freeaddrinfo || !ipv6_getaddrinfo || !ipv6_getnameinfo) {
-		ipv6_freeaddrinfo = freeaddrinfo_stub;
-		ipv6_getaddrinfo = getaddrinfo_stub;
-		ipv6_getnameinfo = getnameinfo_stub;
-	}
-
-	atexit(socket_cleanup);
+	atexit((void(*)(void)) WSACleanup);
 	initialized = 1;
 }
 
@@ -1904,24 +1744,12 @@
 	return gethostbyname(host);
 }
 
-void mingw_freeaddrinfo(struct addrinfo *res)
-{
-	ipv6_freeaddrinfo(res);
-}
-
+#undef getaddrinfo
 int mingw_getaddrinfo(const char *node, const char *service,
 		      const struct addrinfo *hints, struct addrinfo **res)
 {
 	ensure_socket_initialization();
-	return ipv6_getaddrinfo(node, service, hints, res);
-}
-
-int mingw_getnameinfo(const struct sockaddr *sa, socklen_t salen,
-		      char *host, DWORD hostlen, char *serv, DWORD servlen,
-		      int flags)
-{
-	ensure_socket_initialization();
-	return ipv6_getnameinfo(sa, salen, host, hostlen, serv, servlen, flags);
+	return getaddrinfo(node, service, hints, res);
 }
 
 int mingw_socket(int domain, int type, int protocol)
diff --git a/compat/mingw.h b/compat/mingw.h
index 4d73f8a..593bdbf 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -295,18 +295,10 @@
 struct hostent *mingw_gethostbyname(const char *host);
 #define gethostbyname mingw_gethostbyname
 
-void mingw_freeaddrinfo(struct addrinfo *res);
-#define freeaddrinfo mingw_freeaddrinfo
-
 int mingw_getaddrinfo(const char *node, const char *service,
 		      const struct addrinfo *hints, struct addrinfo **res);
 #define getaddrinfo mingw_getaddrinfo
 
-int mingw_getnameinfo(const struct sockaddr *sa, socklen_t salen,
-		      char *host, DWORD hostlen, char *serv, DWORD servlen,
-		      int flags);
-#define getnameinfo mingw_getnameinfo
-
 int mingw_socket(int domain, int type, int protocol);
 #define socket mingw_socket
 
diff --git a/config.mak.uname b/config.mak.uname
index 19ce2f2..b71688e 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -576,13 +576,21 @@
 	ifneq ($(shell expr "$(uname_R)" : '1\.'),2)
 		# MSys2
 		prefix = /usr/
+		# Enable DEP
+		BASIC_LDFLAGS += -Wl,--nxcompat
+		# Enable ASLR (unless debugging)
+		ifneq (,$(findstring -O,$(filter-out -O0 -Og,$(CFLAGS))))
+			BASIC_LDFLAGS += -Wl,--dynamicbase
+		endif
 		ifeq (MINGW32,$(MSYSTEM))
 			prefix = /mingw32
 			HOST_CPU = i686
+			BASIC_LDFLAGS += -Wl,--pic-executable,-e,_mainCRTStartup
 		endif
 		ifeq (MINGW64,$(MSYSTEM))
 			prefix = /mingw64
 			HOST_CPU = x86_64
+			BASIC_LDFLAGS += -Wl,--pic-executable,-e,mainCRTStartup
 		else
 			COMPAT_CFLAGS += -D_USE_32BIT_TIME_T
 			BASIC_LDFLAGS += -Wl,--large-address-aware
diff --git a/contrib/diff-highlight/DiffHighlight.pm b/contrib/diff-highlight/DiffHighlight.pm
index 5367545..7440aa1 100644
--- a/contrib/diff-highlight/DiffHighlight.pm
+++ b/contrib/diff-highlight/DiffHighlight.pm
@@ -4,6 +4,11 @@
 use warnings FATAL => 'all';
 use strict;
 
+# Use the correct value for both UNIX and Windows (/dev/null vs nul)
+use File::Spec;
+
+my $NULL = File::Spec->devnull();
+
 # Highlight by reversing foreground and background. You could do
 # other things like bold or underline if you prefer.
 my @OLD_HIGHLIGHT = (
@@ -134,7 +139,7 @@
 # fallback, which means we will work even if git can't be run.
 sub color_config {
 	my ($key, $default) = @_;
-	my $s = `git config --get-color $key 2>/dev/null`;
+	my $s = `git config --get-color $key 2>$NULL`;
 	return length($s) ? $s : $default;
 }
 
diff --git a/fsmonitor.c b/fsmonitor.c
index 665bd2d..1dee0ad 100644
--- a/fsmonitor.c
+++ b/fsmonitor.c
@@ -129,7 +129,6 @@
 
 void refresh_fsmonitor(struct index_state *istate)
 {
-	static int has_run_once = 0;
 	struct strbuf query_result = STRBUF_INIT;
 	int query_success = 0;
 	size_t bol; /* beginning of line */
@@ -137,9 +136,9 @@
 	char *buf;
 	int i;
 
-	if (!core_fsmonitor || has_run_once)
+	if (!core_fsmonitor || istate->fsmonitor_has_run_once)
 		return;
-	has_run_once = 1;
+	istate->fsmonitor_has_run_once = 1;
 
 	trace_printf_key(&trace_fsmonitor, "refresh fsmonitor");
 	/*
diff --git a/git-cvsexportcommit.perl b/git-cvsexportcommit.perl
index d13f02d..fc00d59 100755
--- a/git-cvsexportcommit.perl
+++ b/git-cvsexportcommit.perl
@@ -431,6 +431,7 @@
 sub safe_pipe_capture {
     my @output;
     if (my $pid = open my $child, '-|') {
+	binmode($child, ":crlf");
 	@output = (<$child>);
 	close $child or die join(' ',@_).": $! $?";
     } else {
diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
index 7bfb673..46af3e6 100755
--- a/git-difftool--helper.sh
+++ b/git-difftool--helper.sh
@@ -71,7 +71,7 @@
 	then
 		merge_tool="$GIT_DIFF_TOOL"
 	else
-		merge_tool="$(get_merge_tool)" || exit
+		merge_tool="$(get_merge_tool)"
 	fi
 fi
 
diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index aaa4eed..204a5ac 100644
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -80,14 +80,18 @@
 	}
 }
 
-diff_mode() {
+diff_mode () {
 	test "$TOOL_MODE" = diff
 }
 
-merge_mode() {
+merge_mode () {
 	test "$TOOL_MODE" = merge
 }
 
+gui_mode () {
+	test "$GIT_MERGETOOL_GUI" = true
+}
+
 translate_merge_tool_path () {
 	echo "$1"
 }
@@ -351,20 +355,36 @@
 }
 
 get_configured_merge_tool () {
-	# If first argument is true, find the guitool instead
-	if test "$1" = true
-	then
-		gui_prefix=gui
-	fi
-
-	# Diff mode first tries diff.(gui)tool and falls back to merge.(gui)tool.
-	# Merge mode only checks merge.(gui)tool
+	keys=
 	if diff_mode
 	then
-		merge_tool=$(git config diff.${gui_prefix}tool || git config merge.${gui_prefix}tool)
+		if gui_mode
+		then
+			keys="diff.guitool merge.guitool diff.tool merge.tool"
+		else
+			keys="diff.tool merge.tool"
+		fi
 	else
-		merge_tool=$(git config merge.${gui_prefix}tool)
+		if gui_mode
+		then
+			keys="merge.guitool merge.tool"
+		else
+			keys="merge.tool"
+		fi
 	fi
+
+	merge_tool=$(
+		IFS=' '
+		for key in $keys
+		do
+			selected=$(git config $key)
+			if test -n "$selected"
+			then
+				echo "$selected"
+				return
+			fi
+		done)
+
 	if test -n "$merge_tool" && ! valid_tool "$merge_tool"
 	then
 		echo >&2 "git config option $TOOL_MODE.${gui_prefix}tool set to unknown tool: $merge_tool"
@@ -404,14 +424,17 @@
 }
 
 get_merge_tool () {
+	is_guessed=false
 	# Check if a merge tool has been configured
 	merge_tool=$(get_configured_merge_tool)
 	# Try to guess an appropriate merge tool if no tool has been set.
 	if test -z "$merge_tool"
 	then
 		merge_tool=$(guess_merge_tool) || exit
+		is_guessed=true
 	fi
 	echo "$merge_tool"
+	test "$is_guessed" = false
 }
 
 mergetool_find_win32_cmd () {
diff --git a/git-mergetool.sh b/git-mergetool.sh
index 01b9ad5..88fa6a9 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -389,7 +389,7 @@
 
 main () {
 	prompt=$(git config --bool mergetool.prompt)
-	gui_tool=false
+	GIT_MERGETOOL_GUI=false
 	guessed_merge_tool=false
 	orderfile=
 
@@ -416,10 +416,10 @@
 			esac
 			;;
 		--no-gui)
-			gui_tool=false
+			GIT_MERGETOOL_GUI=false
 			;;
 		-g|--gui)
-			gui_tool=true
+			GIT_MERGETOOL_GUI=true
 			;;
 		-y|--no-prompt)
 			prompt=false
@@ -449,12 +449,8 @@
 
 	if test -z "$merge_tool"
 	then
-		# Check if a merge tool has been configured
-		merge_tool=$(get_configured_merge_tool $gui_tool)
-		# Try to guess an appropriate merge tool if no tool has been set.
-		if test -z "$merge_tool"
+		if ! merge_tool=$(get_merge_tool)
 		then
-			merge_tool=$(guess_merge_tool) || exit
 			guessed_merge_tool=true
 		fi
 	fi
diff --git a/http.c b/http.c
index 98fb06d..27aa0a3 100644
--- a/http.c
+++ b/http.c
@@ -176,7 +176,7 @@
 	memcpy(ptr, buffer->buf.buf + buffer->posn, size);
 	buffer->posn += size;
 
-	return size;
+	return size / eltsize;
 }
 
 #ifndef NO_CURL_IOCTL
@@ -204,12 +204,12 @@
 	struct strbuf *buffer = buffer_;
 
 	strbuf_add(buffer, ptr, size);
-	return size;
+	return nmemb;
 }
 
 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 {
-	return eltsize * nmemb;
+	return nmemb;
 }
 
 static void closedown_active_slot(struct active_request_slot *slot)
@@ -2319,14 +2319,14 @@
 			BUG("curl_easy_getinfo for HTTP code failed: %s",
 				curl_easy_strerror(c));
 		if (slot->http_code >= 300)
-			return size;
+			return nmemb;
 	}
 
 	do {
 		ssize_t retval = xwrite(freq->localfile,
 					(char *) ptr + posn, size - posn);
 		if (retval < 0)
-			return posn;
+			return posn / eltsize;
 		posn += retval;
 	} while (posn < size);
 
@@ -2339,7 +2339,7 @@
 		the_hash_algo->update_fn(&freq->c, expn,
 					 sizeof(expn) - freq->stream.avail_out);
 	} while (freq->stream.avail_in && freq->zret == Z_OK);
-	return size;
+	return nmemb;
 }
 
 struct http_object_request *new_http_object_request(const char *base_url,
diff --git a/midx.c b/midx.c
index d5d2e95..e7e1fe4 100644
--- a/midx.c
+++ b/midx.c
@@ -192,18 +192,17 @@
 	m->fd = -1;
 
 	for (i = 0; i < m->num_packs; i++) {
-		if (m->packs[i]) {
-			close_pack(m->packs[i]);
-			free(m->packs[i]);
-		}
+		if (m->packs[i])
+			m->packs[i]->multi_pack_index = 0;
 	}
 	FREE_AND_NULL(m->packs);
 	FREE_AND_NULL(m->pack_names);
 }
 
-int prepare_midx_pack(struct multi_pack_index *m, uint32_t pack_int_id)
+int prepare_midx_pack(struct repository *r, struct multi_pack_index *m, uint32_t pack_int_id)
 {
 	struct strbuf pack_name = STRBUF_INIT;
+	struct packed_git *p;
 
 	if (pack_int_id >= m->num_packs)
 		die(_("bad pack-int-id: %u (%u total packs)"),
@@ -215,9 +214,18 @@
 	strbuf_addf(&pack_name, "%s/pack/%s", m->object_dir,
 		    m->pack_names[pack_int_id]);
 
-	m->packs[pack_int_id] = add_packed_git(pack_name.buf, pack_name.len, m->local);
+	p = add_packed_git(pack_name.buf, pack_name.len, m->local);
 	strbuf_release(&pack_name);
-	return !m->packs[pack_int_id];
+
+	if (!p)
+		return 1;
+
+	p->multi_pack_index = 1;
+	m->packs[pack_int_id] = p;
+	install_packed_git(r, p);
+	list_add_tail(&p->mru, &r->objects->packed_git_mru);
+
+	return 0;
 }
 
 int bsearch_midx(const struct object_id *oid, struct multi_pack_index *m, uint32_t *result)
@@ -261,7 +269,10 @@
 	return get_be32(m->chunk_object_offsets + pos * MIDX_CHUNK_OFFSET_WIDTH);
 }
 
-static int nth_midxed_pack_entry(struct multi_pack_index *m, struct pack_entry *e, uint32_t pos)
+static int nth_midxed_pack_entry(struct repository *r,
+				 struct multi_pack_index *m,
+				 struct pack_entry *e,
+				 uint32_t pos)
 {
 	uint32_t pack_int_id;
 	struct packed_git *p;
@@ -271,7 +282,7 @@
 
 	pack_int_id = nth_midxed_pack_int_id(m, pos);
 
-	if (prepare_midx_pack(m, pack_int_id))
+	if (prepare_midx_pack(r, m, pack_int_id))
 		die(_("error preparing packfile from multi-pack-index"));
 	p = m->packs[pack_int_id];
 
@@ -301,14 +312,17 @@
 	return 1;
 }
 
-int fill_midx_entry(const struct object_id *oid, struct pack_entry *e, struct multi_pack_index *m)
+int fill_midx_entry(struct repository * r,
+		    const struct object_id *oid,
+		    struct pack_entry *e,
+		    struct multi_pack_index *m)
 {
 	uint32_t pos;
 
 	if (!bsearch_midx(oid, m, &pos))
 		return 0;
 
-	return nth_midxed_pack_entry(m, e, pos);
+	return nth_midxed_pack_entry(r, m, e, pos);
 }
 
 /* Match "foo.idx" against either "foo.pack" _or_ "foo.idx". */
@@ -1020,7 +1034,7 @@
 			display_progress(progress, _n); \
 	} while (0)
 
-int verify_midx_file(const char *object_dir)
+int verify_midx_file(struct repository *r, const char *object_dir)
 {
 	struct pair_pos_vs_id *pairs = NULL;
 	uint32_t i;
@@ -1034,7 +1048,7 @@
 	progress = start_progress(_("Looking for referenced packfiles"),
 				  m->num_packs);
 	for (i = 0; i < m->num_packs; i++) {
-		if (prepare_midx_pack(m, i))
+		if (prepare_midx_pack(r, m, i))
 			midx_report("failed to load pack in position %d", i);
 
 		display_progress(progress, i + 1);
@@ -1099,7 +1113,7 @@
 
 		nth_midxed_object_oid(&oid, m, pairs[i].pos);
 
-		if (!fill_midx_entry(&oid, &e, m)) {
+		if (!fill_midx_entry(r, &oid, &e, m)) {
 			midx_report(_("failed to load pack entry for oid[%d] = %s"),
 				    pairs[i].pos, oid_to_hex(&oid));
 			continue;
diff --git a/midx.h b/midx.h
index 26dd042..3eb2973 100644
--- a/midx.h
+++ b/midx.h
@@ -5,6 +5,7 @@
 
 struct object_id;
 struct pack_entry;
+struct repository;
 
 #define GIT_TEST_MULTI_PACK_INDEX "GIT_TEST_MULTI_PACK_INDEX"
 
@@ -37,18 +38,18 @@
 };
 
 struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local);
-int prepare_midx_pack(struct multi_pack_index *m, uint32_t pack_int_id);
+int prepare_midx_pack(struct repository *r, struct multi_pack_index *m, uint32_t pack_int_id);
 int bsearch_midx(const struct object_id *oid, struct multi_pack_index *m, uint32_t *result);
 struct object_id *nth_midxed_object_oid(struct object_id *oid,
 					struct multi_pack_index *m,
 					uint32_t n);
-int fill_midx_entry(const struct object_id *oid, struct pack_entry *e, struct multi_pack_index *m);
+int fill_midx_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e, struct multi_pack_index *m);
 int midx_contains_pack(struct multi_pack_index *m, const char *idx_or_pack_name);
 int prepare_multi_pack_index_one(struct repository *r, const char *object_dir, int local);
 
 int write_midx_file(const char *object_dir);
 void clear_midx_file(struct repository *r);
-int verify_midx_file(const char *object_dir);
+int verify_midx_file(struct repository *r, const char *object_dir);
 
 void close_midx(struct multi_pack_index *m);
 
diff --git a/notes.h b/notes.h
index 414bc68..76337f2 100644
--- a/notes.h
+++ b/notes.h
@@ -276,12 +276,10 @@
 
 /*
  * Append notes for the given 'object_sha1' from all trees set up by
- * init_display_notes() to 'sb'.  The 'flags' are a bitwise
- * combination of
+ * init_display_notes() to 'sb'.
  *
- * - NOTES_SHOW_HEADER: add a 'Notes (refname):' header
- *
- * - NOTES_INDENT: indent the notes by 4 places
+ * If 'raw' is false the note will be indented by 4 places and
+ * a 'Notes (refname):' header added.
  *
  * You *must* call init_display_notes() before using this function.
  */
diff --git a/object-store.h b/object-store.h
index 46a1da7..272e01e 100644
--- a/object-store.h
+++ b/object-store.h
@@ -76,7 +76,8 @@
 		 pack_keep_in_core:1,
 		 freshened:1,
 		 do_not_close:1,
-		 pack_promisor:1;
+		 pack_promisor:1,
+		 multi_pack_index:1;
 	unsigned char hash[GIT_MAX_RAWSZ];
 	struct revindex_entry *revindex;
 	/* something like ".git/objects/pack/xxxxx.pack" */
@@ -129,12 +130,6 @@
 	struct list_head packed_git_mru;
 
 	/*
-	 * A linked list containing all packfiles, starting with those
-	 * contained in the multi_pack_index.
-	 */
-	struct packed_git *all_packs;
-
-	/*
 	 * A fast, rough count of the number of objects in the repository.
 	 * These two fields are not meant for direct access. Use
 	 * approximate_object_count() instead.
diff --git a/packfile.c b/packfile.c
index 9f52af9..49c8544 100644
--- a/packfile.c
+++ b/packfile.c
@@ -994,8 +994,6 @@
 	}
 	rearrange_packed_git(r);
 
-	r->objects->all_packs = NULL;
-
 	prepare_packed_git_mru(r);
 	r->objects->packed_git_initialized = 1;
 }
@@ -1026,26 +1024,16 @@
 
 struct packed_git *get_all_packs(struct repository *r)
 {
+	struct multi_pack_index *m;
+
 	prepare_packed_git(r);
-
-	if (!r->objects->all_packs) {
-		struct packed_git *p = r->objects->packed_git;
-		struct multi_pack_index *m;
-
-		for (m = r->objects->multi_pack_index; m; m = m->next) {
-			uint32_t i;
-			for (i = 0; i < m->num_packs; i++) {
-				if (!prepare_midx_pack(m, i)) {
-					m->packs[i]->next = p;
-					p = m->packs[i];
-				}
-			}
-		}
-
-		r->objects->all_packs = p;
+	for (m = r->objects->multi_pack_index; m; m = m->next) {
+		uint32_t i;
+		for (i = 0; i < m->num_packs; i++)
+			prepare_midx_pack(r, m, i);
 	}
 
-	return r->objects->all_packs;
+	return r->objects->packed_git;
 }
 
 struct list_head *get_packed_git_mru(struct repository *r)
@@ -1998,13 +1986,13 @@
 		return 0;
 
 	for (m = r->objects->multi_pack_index; m; m = m->next) {
-		if (fill_midx_entry(oid, e, m))
+		if (fill_midx_entry(r, oid, e, m))
 			return 1;
 	}
 
 	list_for_each(pos, &r->objects->packed_git_mru) {
 		struct packed_git *p = list_entry(pos, struct packed_git, mru);
-		if (fill_pack_entry(oid, e, p)) {
+		if (!p->multi_pack_index && fill_pack_entry(oid, e, p)) {
 			list_move(&p->mru, &r->objects->packed_git_mru);
 			return 1;
 		}
diff --git a/parse-options.c b/parse-options.c
index cb24f1a..987e27c 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -261,6 +261,35 @@
 	return PARSE_OPT_UNKNOWN;
 }
 
+static int has_string(const char *it, const char **array)
+{
+	while (*array)
+		if (!strcmp(it, *(array++)))
+			return 1;
+	return 0;
+}
+
+static int is_alias(struct parse_opt_ctx_t *ctx,
+		    const struct option *one_opt,
+		    const struct option *another_opt)
+{
+	const char **group;
+
+	if (!ctx->alias_groups)
+		return 0;
+
+	if (!one_opt->long_name || !another_opt->long_name)
+		return 0;
+
+	for (group = ctx->alias_groups; *group; group += 3) {
+		/* it and other are from the same family? */
+		if (has_string(one_opt->long_name, group) &&
+		    has_string(another_opt->long_name, group))
+			return 1;
+	}
+	return 0;
+}
+
 static enum parse_opt_result parse_long_opt(
 	struct parse_opt_ctx_t *p, const char *arg,
 	const struct option *options)
@@ -298,7 +327,8 @@
 			if (!(p->flags & PARSE_OPT_KEEP_UNKNOWN) &&
 			    !strncmp(long_name, arg, arg_end - arg)) {
 is_abbreviated:
-				if (abbrev_option) {
+				if (abbrev_option &&
+				    !is_alias(p, abbrev_option, options)) {
 					/*
 					 * If this is abbreviated, it is
 					 * ambiguous. So when there is no
@@ -447,6 +477,10 @@
 			if (opts->callback)
 				BUG("OPTION_LOWLEVEL_CALLBACK needs no high level callback");
 			break;
+		case OPTION_ALIAS:
+			BUG("OPT_ALIAS() should not remain at this point. "
+			    "Are you using parse_options_step() directly?\n"
+			    "That case is not supported yet.");
 		default:
 			; /* ok. (usually accepts an argument) */
 		}
@@ -458,11 +492,10 @@
 		exit(128);
 }
 
-void parse_options_start(struct parse_opt_ctx_t *ctx,
-			 int argc, const char **argv, const char *prefix,
-			 const struct option *options, int flags)
+static void parse_options_start_1(struct parse_opt_ctx_t *ctx,
+				  int argc, const char **argv, const char *prefix,
+				  const struct option *options, int flags)
 {
-	memset(ctx, 0, sizeof(*ctx));
 	ctx->argc = argc;
 	ctx->argv = argv;
 	if (!(flags & PARSE_OPT_ONE_SHOT)) {
@@ -484,6 +517,14 @@
 	parse_options_check(options);
 }
 
+void parse_options_start(struct parse_opt_ctx_t *ctx,
+			 int argc, const char **argv, const char *prefix,
+			 const struct option *options, int flags)
+{
+	memset(ctx, 0, sizeof(*ctx));
+	parse_options_start_1(ctx, argc, argv, prefix, options, flags);
+}
+
 static void show_negated_gitcomp(const struct option *opts, int nr_noopts)
 {
 	int printed_dashdash = 0;
@@ -575,6 +616,83 @@
 	return PARSE_OPT_COMPLETE;
 }
 
+/*
+ * Scan and may produce a new option[] array, which should be used
+ * instead of the original 'options'.
+ *
+ * Right now this is only used to preprocess and substitue
+ * OPTION_ALIAS.
+ */
+static struct option *preprocess_options(struct parse_opt_ctx_t *ctx,
+					 const struct option *options)
+{
+	struct option *newopt;
+	int i, nr, alias;
+	int nr_aliases = 0;
+
+	for (nr = 0; options[nr].type != OPTION_END; nr++) {
+		if (options[nr].type == OPTION_ALIAS)
+			nr_aliases++;
+	}
+
+	if (!nr_aliases)
+		return NULL;
+
+	ALLOC_ARRAY(newopt, nr + 1);
+	COPY_ARRAY(newopt, options, nr + 1);
+
+	/* each alias has two string pointers and NULL */
+	CALLOC_ARRAY(ctx->alias_groups, 3 * (nr_aliases + 1));
+
+	for (alias = 0, i = 0; i < nr; i++) {
+		int short_name;
+		const char *long_name;
+		const char *source;
+		int j;
+
+		if (newopt[i].type != OPTION_ALIAS)
+			continue;
+
+		short_name = newopt[i].short_name;
+		long_name = newopt[i].long_name;
+		source = newopt[i].value;
+
+		if (!long_name)
+			BUG("An alias must have long option name");
+
+		for (j = 0; j < nr; j++) {
+			const char *name = options[j].long_name;
+
+			if (!name || strcmp(name, source))
+				continue;
+
+			if (options[j].type == OPTION_ALIAS)
+				BUG("No please. Nested aliases are not supported.");
+
+			/*
+			 * NEEDSWORK: this is a bit inconsistent because
+			 * usage_with_options() on the original options[] will print
+			 * help string as "alias of %s" but "git cmd -h" will
+			 * print the original help string.
+			 */
+			memcpy(newopt + i, options + j, sizeof(*newopt));
+			newopt[i].short_name = short_name;
+			newopt[i].long_name = long_name;
+			break;
+		}
+
+		if (j == nr)
+			BUG("could not find source option '%s' of alias '%s'",
+			    source, newopt[i].long_name);
+		ctx->alias_groups[alias * 3 + 0] = newopt[i].long_name;
+		ctx->alias_groups[alias * 3 + 1] = options[j].long_name;
+		ctx->alias_groups[alias * 3 + 2] = NULL;
+		alias++;
+	}
+
+	return newopt;
+}
+
 static int usage_with_options_internal(struct parse_opt_ctx_t *,
 				       const char * const *,
 				       const struct option *, int, int);
@@ -714,11 +832,16 @@
 		  int flags)
 {
 	struct parse_opt_ctx_t ctx;
+	struct option *real_options;
 
 	disallow_abbreviated_options =
 		git_env_bool("GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS", 0);
 
-	parse_options_start(&ctx, argc, argv, prefix, options, flags);
+	memset(&ctx, 0, sizeof(ctx));
+	real_options = preprocess_options(&ctx, options);
+	if (real_options)
+		options = real_options;
+	parse_options_start_1(&ctx, argc, argv, prefix, options, flags);
 	switch (parse_options_step(&ctx, options, usagestr)) {
 	case PARSE_OPT_HELP:
 	case PARSE_OPT_ERROR:
@@ -741,6 +864,8 @@
 	}
 
 	precompose_argv(argc, argv);
+	free(real_options);
+	free(ctx.alias_groups);
 	return parse_options_end(&ctx);
 }
 
@@ -835,6 +960,12 @@
 			fputc('\n', outfile);
 			pad = USAGE_OPTS_WIDTH;
 		}
+		if (opts->type == OPTION_ALIAS) {
+			fprintf(outfile, "%*s", pad + USAGE_GAP, "");
+			fprintf_ln(outfile, _("alias of --%s"),
+				   (const char *)opts->value);
+			continue;
+		}
 		fprintf(outfile, "%*s%s\n", pad + USAGE_GAP, "", _(opts->help));
 	}
 	fputc('\n', outfile);
diff --git a/parse-options.h b/parse-options.h
index cd75683..ac6ba8a 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -7,6 +7,7 @@
 	OPTION_ARGUMENT,
 	OPTION_GROUP,
 	OPTION_NUMBER,
+	OPTION_ALIAS,
 	/* options with no arguments */
 	OPTION_BIT,
 	OPTION_NEGBIT,
@@ -183,6 +184,9 @@
 	  N_("no-op (backward compatibility)"),		\
 	  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, parse_opt_noop_cb }
 
+#define OPT_ALIAS(s, l, source_long_name) \
+	{ OPTION_ALIAS, (s), (l), (source_long_name) }
+
 /*
  * parse_options() will filter out the processed options and leave the
  * non-option arguments in argv[]. argv0 is assumed program name and
@@ -258,6 +262,8 @@
 	const char *opt;
 	int flags;
 	const char *prefix;
+	const char **alias_groups; /* must be in groups of 3 elements! */
+	struct option *updated_options;
 };
 
 void parse_options_start(struct parse_opt_ctx_t *ctx,
diff --git a/read-cache.c b/read-cache.c
index 4fad4e3..22e7b99 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -2326,6 +2326,7 @@
 	free_name_hash(istate);
 	cache_tree_free(&(istate->cache_tree));
 	istate->initialized = 0;
+	istate->fsmonitor_has_run_once = 0;
 	FREE_AND_NULL(istate->cache);
 	istate->cache_alloc = 0;
 	discard_split_index(istate);
diff --git a/sha1-name.c b/sha1-name.c
index 775a73d..b4f5cad 100644
--- a/sha1-name.c
+++ b/sha1-name.c
@@ -157,6 +157,9 @@
 	uint32_t num, i, first = 0;
 	const struct object_id *current = NULL;
 
+	if (p->multi_pack_index)
+		return;
+
 	if (open_pack_index(p) || !p->num_objects)
 		return;
 
@@ -625,6 +628,9 @@
 	struct object_id oid;
 	const struct object_id *mad_oid;
 
+	if (p->multi_pack_index)
+		return;
+
 	if (open_pack_index(p) || !p->num_objects)
 		return;
 
diff --git a/sha1collisiondetection b/sha1collisiondetection
index 1603399..855827c 160000
--- a/sha1collisiondetection
+++ b/sha1collisiondetection
@@ -1 +1 @@
-Subproject commit 16033998da4b273aebd92c84b1e1b12e4aaf7009
+Subproject commit 855827c583bc30645ba427885caa40c5b81764d2
diff --git a/sha1dc/sha1.c b/sha1dc/sha1.c
index 5931cf2..9d3cf81 100644
--- a/sha1dc/sha1.c
+++ b/sha1dc/sha1.c
@@ -93,7 +93,7 @@
 #define SHA1DC_BIGENDIAN
 
 /* Not under GCC-alike or glibc or *BSD or newlib or <processor whitelist> */
-#elif (defined(_AIX))
+#elif (defined(_AIX) || defined(__hpux))
 
 /*
  * Defines Big Endian on a whitelist of OSs that are known to be Big
diff --git a/t/check-non-portable-shell.pl b/t/check-non-portable-shell.pl
index 166d64d..38bfeeb 100755
--- a/t/check-non-portable-shell.pl
+++ b/t/check-non-portable-shell.pl
@@ -27,14 +27,14 @@
 	close $f;
 }
 
+my $line = '';
 while (<>) {
 	chomp;
+	$line .= $_;
 	# stitch together incomplete lines (those ending with "\")
-	while (s/\\$//) {
-		$_ .= readline;
-		chomp;
-	}
+	next if $line =~ s/\\$//;
 
+	$_ = $line;
 	/\bcp\s+-a/ and err 'cp -a is not portable';
 	/\bsed\s+-[^efn]\s+/ and err 'sed option not portable (use only -n, -e, -f)';
 	/\becho\s+-[neE]/ and err 'echo with option is not portable (use printf)';
@@ -48,6 +48,7 @@
 	/\bexport\s+[A-Za-z0-9_]*=/ and err '"export FOO=bar" is not portable (use FOO=bar && export FOO)';
 	/^\s*([A-Z0-9_]+=(\w+|(["']).*?\3)\s+)+(\w+)/ and exists($func{$4}) and
 		err '"FOO=bar shell_func" assignment extends beyond "shell_func"';
+	$line = '';
 	# this resets our $. for each file
 	close ARGV if eof;
 }
diff --git a/t/helper/test-parse-options.c b/t/helper/test-parse-options.c
index 2232b2f..af82db0 100644
--- a/t/helper/test-parse-options.c
+++ b/t/helper/test-parse-options.c
@@ -149,6 +149,9 @@
 		OPT_CALLBACK(0, "expect", &expect, "string",
 			     "expected output in the variable dump",
 			     collect_expect),
+		OPT_GROUP("Alias"),
+		OPT_STRING('A', "alias-source", &string, "string", "get a string"),
+		OPT_ALIAS('Z', "alias-target", "alias-source"),
 		OPT_END(),
 	};
 	int i;
diff --git a/t/helper/test-read-cache.c b/t/helper/test-read-cache.c
index d674c88..7e79b55 100644
--- a/t/helper/test-read-cache.c
+++ b/t/helper/test-read-cache.c
@@ -1,14 +1,36 @@
 #include "test-tool.h"
 #include "cache.h"
+#include "config.h"
 
 int cmd__read_cache(int argc, const char **argv)
 {
-	int i, cnt = 1;
+	int i, cnt = 1, namelen;
+	const char *name = NULL;
+
+	if (argc > 1 && skip_prefix(argv[1], "--print-and-refresh=", &name)) {
+		namelen = strlen(name);
+		argc--;
+		argv++;
+	}
+
 	if (argc == 2)
 		cnt = strtol(argv[1], NULL, 0);
 	setup_git_directory();
+	git_config(git_default_config, NULL);
 	for (i = 0; i < cnt; i++) {
 		read_cache();
+		if (name) {
+			int pos;
+
+			refresh_index(&the_index, REFRESH_QUIET,
+				      NULL, NULL, NULL);
+			pos = index_name_pos(&the_index, name, namelen);
+			if (pos < 0)
+				die("%s not in index", name);
+			printf("%s is%s up to date\n", name,
+			       ce_uptodate(the_index.cache[pos]) ? "" : " not");
+			write_file(name, "%d\n", i);
+		}
 		discard_cache();
 	}
 	return 0;
diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 06a81b5..5c1c86c 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -76,6 +76,7 @@
 PassEnv GIT_VALGRIND_OPTIONS
 PassEnv GNUPGHOME
 PassEnv ASAN_OPTIONS
+PassEnv LSAN_OPTIONS
 PassEnv GIT_TRACE
 PassEnv GIT_CONFIG_NOSYSTEM
 PassEnv GIT_TEST_SIDEBAND_ALL
diff --git a/t/perf/README b/t/perf/README
index be12090..c7b70e2 100644
--- a/t/perf/README
+++ b/t/perf/README
@@ -45,7 +45,7 @@
 
     $ ./p0001-rev-list.sh
     [...]
-    $ GIT_BUILD_DIR=/path/to/other/git ./p0001-rev-list.sh
+    $ ./run /path/to/other/git -- ./p0001-rev-list.sh
     [...]
     $ ./aggregate.perl . /path/to/other/git ./p0001-rev-list.sh
 
diff --git a/t/perf/aggregate.perl b/t/perf/aggregate.perl
index 76dd48f..66554d2 100755
--- a/t/perf/aggregate.perl
+++ b/t/perf/aggregate.perl
@@ -5,6 +5,7 @@
 use warnings;
 use Getopt::Long;
 use Git;
+use Cwd qw(realpath);
 
 sub get_times {
 	my $name = shift;
@@ -98,18 +99,21 @@
 while (scalar @ARGV) {
 	my $arg = $ARGV[0];
 	my $dir;
+	my $prefix = '';
 	last if -f $arg or $arg eq "--";
 	if (! -d $arg) {
 		my $rev = Git::command_oneline(qw(rev-parse --verify), $arg);
 		$dir = "build/".$rev;
+	} elsif ($arg eq '.') {
+		$dir = '.';
 	} else {
-		$arg =~ s{/*$}{};
-		$dir = $arg;
-		$dirabbrevs{$dir} = $dir;
+		$dir = realpath($arg);
+		$dirnames{$dir} = $dir;
+		$prefix .= 'bindir';
 	}
 	push @dirs, $dir;
-	$dirnames{$dir} = $arg;
-	my $prefix = $dir;
+	$dirnames{$dir} ||= $arg;
+	$prefix .= $dir;
 	$prefix =~ tr/^a-zA-Z0-9/_/c;
 	$prefixes{$dir} = $prefix . '.';
 	shift @ARGV;
@@ -311,9 +315,6 @@
 		$environment = $reponame;
 	} elsif (exists $ENV{GIT_PERF_REPO_NAME} and $ENV{GIT_PERF_REPO_NAME} ne "") {
 		$environment = $ENV{GIT_PERF_REPO_NAME};
-	} elsif (exists $ENV{GIT_TEST_INSTALLED} and $ENV{GIT_TEST_INSTALLED} ne "") {
-		$environment = $ENV{GIT_TEST_INSTALLED};
-		$environment =~ s|/bin-wrappers$||;
 	} else {
 		$environment = `uname -r`;
 		chomp $environment;
diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index 169f92e..b58a43e 100644
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -21,19 +21,21 @@
 # because it will change our working directory.
 TEST_DIRECTORY=$(pwd)/..
 TEST_OUTPUT_DIRECTORY=$(pwd)
-ABSOLUTE_GIT_TEST_INSTALLED=$(
-	test -n "$GIT_TEST_INSTALLED" && cd "$GIT_TEST_INSTALLED" && pwd)
 
 TEST_NO_CREATE_REPO=t
 TEST_NO_MALLOC_CHECK=t
 
 . ../test-lib.sh
 
-if test -z "$GIT_TEST_INSTALLED"; then
-	perf_results_prefix=
-else
-	perf_results_prefix=$(printf "%s" "${GIT_TEST_INSTALLED%/bin-wrappers}" | tr -c "[a-zA-Z0-9]" "[_*]")"."
-	GIT_TEST_INSTALLED=$ABSOLUTE_GIT_TEST_INSTALLED
+if test -n "$GIT_TEST_INSTALLED" -a -z "$PERF_SET_GIT_TEST_INSTALLED"
+then
+	error "Do not use GIT_TEST_INSTALLED with the perf tests.
+
+Instead use:
+
+    ./run <path-to-git> -- <tests>
+
+See t/perf/README for details."
 fi
 
 # Variables from test-lib that are normally internal to the tests; we
@@ -179,7 +181,7 @@
 		base=$(basename "$0" .sh)
 		echo "$test_count" >>"$perf_results_dir"/$base.subtests
 		echo "$1" >"$perf_results_dir"/$base.$test_count.descr
-		base="$perf_results_dir"/"$perf_results_prefix$(basename "$0" .sh)"."$test_count"
+		base="$perf_results_dir"/"$PERF_RESULTS_PREFIX$(basename "$0" .sh)"."$test_count"
 		"$test_wrapper_func_" "$@"
 	fi
 
diff --git a/t/perf/run b/t/perf/run
index 9aaa733..c7b8610 100755
--- a/t/perf/run
+++ b/t/perf/run
@@ -70,6 +70,24 @@
 	) || die "failed to build revision '$mydir'"
 }
 
+set_git_test_installed () {
+	mydir=$1
+
+	mydir_abs=$(cd $mydir && pwd)
+	mydir_abs_wrappers="$mydir_abs_wrappers/bin-wrappers"
+	if test -d "$mydir_abs_wrappers"
+	then
+		GIT_TEST_INSTALLED=$mydir_abs_wrappers
+	else
+		# Older versions of git lacked bin-wrappers;
+		# fallback to the files in the root.
+		GIT_TEST_INSTALLED=$mydir_abs
+	fi
+	export GIT_TEST_INSTALLED
+	PERF_SET_GIT_TEST_INSTALLED=true
+	export PERF_SET_GIT_TEST_INSTALLED
+}
+
 run_dirs_helper () {
 	mydir=${1%/}
 	shift
@@ -79,7 +97,16 @@
 	if test $# -gt 0 -a "$1" = --; then
 		shift
 	fi
-	if [ ! -d "$mydir" ]; then
+
+	PERF_RESULTS_PREFIX=
+	if test "$mydir" = "."
+	then
+		unset GIT_TEST_INSTALLED
+	elif test -d "$mydir"
+	then
+		PERF_RESULTS_PREFIX=bindir$(cd $mydir && printf "%s" "$(pwd)" | tr -c "[a-zA-Z0-9]" "_").
+		set_git_test_installed "$mydir"
+	else
 		rev=$(git rev-parse --verify "$mydir" 2>/dev/null) ||
 		die "'$mydir' is neither a directory nor a valid revision"
 		if [ ! -d build/$rev ]; then
@@ -87,16 +114,12 @@
 		fi
 		build_git_rev $rev "$mydir"
 		mydir=build/$rev
+
+		PERF_RESULTS_PREFIX=build_$rev.
+		set_git_test_installed "$mydir"
 	fi
-	if test "$mydir" = .; then
-		unset GIT_TEST_INSTALLED
-	else
-		GIT_TEST_INSTALLED="$mydir/bin-wrappers"
-		# Older versions of git lacked bin-wrappers; fallback to the
-		# files in the root.
-		test -d "$GIT_TEST_INSTALLED" || GIT_TEST_INSTALLED=$mydir
-		export GIT_TEST_INSTALLED
-	fi
+	export PERF_RESULTS_PREFIX
+
 	run_one_dir "$@"
 }
 
diff --git a/t/t0040-parse-options.sh b/t/t0040-parse-options.sh
index 800b3ea..cebc77f 100755
--- a/t/t0040-parse-options.sh
+++ b/t/t0040-parse-options.sh
@@ -48,6 +48,12 @@
     -q, --quiet           be quiet
     --expect <string>     expected output in the variable dump
 
+Alias
+    -A, --alias-source <string>
+                          get a string
+    -Z, --alias-target <string>
+                          get a string
+
 EOF
 
 test_expect_success 'test help' '
@@ -224,6 +230,17 @@
 	test-tool parse-options --expect="string: 123" --st 123
 '
 
+test_expect_success 'Alias options do not contribute to abbreviation' '
+	test-tool parse-options --alias-source 123 >output &&
+	grep "^string: 123" output &&
+	test-tool parse-options --alias-target 123 >output &&
+	grep "^string: 123" output &&
+	test_must_fail test-tool parse-options --alias &&
+	GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS=false \
+	test-tool parse-options --alias 123 >output &&
+	grep "^string: 123" output
+'
+
 cat >typo.err <<\EOF
 error: did you mean `--boolean` (with two dashes ?)
 EOF
diff --git a/t/t2018-checkout-branch.sh b/t/t2018-checkout-branch.sh
index c5014ad..822381d 100755
--- a/t/t2018-checkout-branch.sh
+++ b/t/t2018-checkout-branch.sh
@@ -60,38 +60,47 @@
 '
 
 test_expect_success 'checkout -b to a new branch, set to HEAD' '
+	test_when_finished "
+		git checkout branch1 &&
+		test_might_fail git branch -D branch2" &&
 	do_checkout branch2
 '
 
-test_expect_success 'checkout -b to a new branch, set to an explicit ref' '
-	git checkout branch1 &&
-	git branch -D branch2 &&
+test_expect_success 'checkout -b to a merge base' '
+	test_when_finished "
+		git checkout branch1 &&
+		test_might_fail git branch -D branch2" &&
+	git checkout -b branch2 branch1...
+'
 
+test_expect_success 'checkout -b to a new branch, set to an explicit ref' '
+	test_when_finished "
+		git checkout branch1 &&
+		test_might_fail git branch -D branch2" &&
 	do_checkout branch2 $HEAD1
 '
 
 test_expect_success 'checkout -b to a new branch with unmergeable changes fails' '
-	git checkout branch1 &&
-
-	# clean up from previous test
-	git branch -D branch2 &&
-
 	setup_dirty_unmergeable &&
 	test_must_fail do_checkout branch2 $HEAD1 &&
 	test_dirty_unmergeable
 '
 
 test_expect_success 'checkout -f -b to a new branch with unmergeable changes discards changes' '
+	test_when_finished "
+		git checkout branch1 &&
+		test_might_fail git branch -D branch2" &&
+
 	# still dirty and on branch1
 	do_checkout branch2 $HEAD1 "-f -b" &&
 	test_must_fail test_dirty_unmergeable
 '
 
 test_expect_success 'checkout -b to a new branch preserves mergeable changes' '
-	git checkout branch1 &&
-
-	# clean up from previous test
-	git branch -D branch2 &&
+	test_when_finished "
+		git reset --hard &&
+		git checkout branch1 &&
+		test_might_fail git branch -D branch2" &&
 
 	setup_dirty_mergeable &&
 	do_checkout branch2 $HEAD1 &&
@@ -99,27 +108,18 @@
 '
 
 test_expect_success 'checkout -f -b to a new branch with mergeable changes discards changes' '
-	# clean up from previous test
-	git reset --hard &&
-
-	git checkout branch1 &&
-
-	# clean up from previous test
-	git branch -D branch2 &&
-
+	test_when_finished git reset --hard HEAD &&
 	setup_dirty_mergeable &&
 	do_checkout branch2 $HEAD1 "-f -b" &&
 	test_must_fail test_dirty_mergeable
 '
 
 test_expect_success 'checkout -b to an existing branch fails' '
-	git reset --hard HEAD &&
-
+	test_when_finished git reset --hard HEAD &&
 	test_must_fail do_checkout branch2 $HEAD2
 '
 
 test_expect_success 'checkout -b to @{-1} fails with the right branch name' '
-	git reset --hard HEAD &&
 	git checkout branch1 &&
 	git checkout branch2 &&
 	echo  >expect "fatal: A branch named '\''branch1'\'' already exists." &&
@@ -133,6 +133,12 @@
 	do_checkout branch2 "" -B
 '
 
+test_expect_success 'checkout -B to a merge base' '
+	git checkout branch1 &&
+
+	git checkout -B branch2 branch1...
+'
+
 test_expect_success 'checkout -B to an existing branch from detached HEAD resets branch to HEAD' '
 	git checkout $(git rev-parse --verify HEAD) &&
 
@@ -160,6 +166,7 @@
 '
 
 test_expect_success 'checkout -B to an existing branch preserves mergeable changes' '
+	test_when_finished git reset --hard &&
 	git checkout branch1 &&
 
 	setup_dirty_mergeable &&
@@ -168,9 +175,6 @@
 '
 
 test_expect_success 'checkout -f -B to an existing branch with mergeable changes discards changes' '
-	# clean up from previous test
-	git reset --hard &&
-
 	git checkout branch1 &&
 
 	setup_dirty_mergeable &&
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index e9ad50b..e9d7084 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -42,6 +42,10 @@
 	git branch a/b/c && test_path_is_file .git/refs/heads/a/b/c
 '
 
+test_expect_success 'git branch mb master... should create a branch' '
+	git branch mb master... && test_path_is_file .git/refs/heads/mb
+'
+
 test_expect_success 'git branch HEAD should fail' '
 	test_must_fail git branch HEAD
 '
@@ -316,8 +320,8 @@
 test_expect_success 'git branch --column' '
 	COLUMNS=81 git branch --column=column >actual &&
 	cat >expected <<\EOF &&
-  a/b/c     bam       foo       l       * master    n         o/p       r
-  abc       bar       j/k       m/m       master2   o/o       q
+  a/b/c     bam       foo       l       * master    mb        o/o       q
+  abc       bar       j/k       m/m       master2   n         o/p       r
 EOF
 	test_cmp expected actual
 '
@@ -339,6 +343,7 @@
   m/m
 * master
   master2
+  mb
   n
   o/o
   o/p
@@ -356,8 +361,8 @@
 	git config --unset column.branch &&
 	git config --unset column.ui &&
 	cat >expected <<\EOF &&
-  a/b/c   bam   foo   l   * master    n     o/p   r
-  abc     bar   j/k   m/m   master2   o/o   q
+  a/b/c   bam   foo   l   * master    mb   o/o   q
+  abc     bar   j/k   m/m   master2   n    o/p   r
 EOF
 	test_cmp expected actual
 '
@@ -381,6 +386,7 @@
   m/m
 * master
   master2
+  mb
   n
   o/o
   o/p
diff --git a/t/t4253-am-keep-cr-dos.sh b/t/t4253-am-keep-cr-dos.sh
index 553fe3e..6e1b73e 100755
--- a/t/t4253-am-keep-cr-dos.sh
+++ b/t/t4253-am-keep-cr-dos.sh
@@ -51,14 +51,16 @@
 
 test_expect_success 'am with dos files with --keep-cr' '
 	git checkout -b dosfiles-keep-cr initial &&
-	git format-patch -k --stdout initial..master | git am --keep-cr -k -3 &&
+	git format-patch -k --stdout initial..master >output &&
+	git am --keep-cr -k -3 output &&
 	git diff --exit-code master
 '
 
 test_expect_success 'am with dos files config am.keepcr' '
 	git config am.keepcr 1 &&
 	git checkout -b dosfiles-conf-keepcr initial &&
-	git format-patch -k --stdout initial..master | git am -k -3 &&
+	git format-patch -k --stdout initial..master >output &&
+	git am -k -3 output &&
 	git diff --exit-code master
 '
 
diff --git a/t/t5580-clone-push-unc.sh b/t/t5580-clone-push-unc.sh
index 217adf3..b3c8a92 100755
--- a/t/t5580-clone-push-unc.sh
+++ b/t/t5580-clone-push-unc.sh
@@ -62,4 +62,16 @@
 	test_i18ngrep ! "unable to access" err
 '
 
+test_expect_success 'unc alternates' '
+	tree="$(git rev-parse HEAD:)" &&
+	mkdir test-unc-alternate &&
+	(
+		cd test-unc-alternate &&
+		git init &&
+		test_must_fail git show $tree &&
+		echo "$UNCPATH/.git/objects" >.git/objects/info/alternates &&
+		git show $tree
+	)
+'
+
 test_done
diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh
index 7411bf7..515c673 100755
--- a/t/t6500-gc.sh
+++ b/t/t6500-gc.sh
@@ -181,7 +181,15 @@
 	# now fake a concurrent gc that holds the lock; we can use our
 	# shell pid so that it looks valid.
 	hostname=$(hostname || echo unknown) &&
-	printf "$$ %s" "$hostname" >.git/gc.pid &&
+	shell_pid=$$ &&
+	if test_have_prereq MINGW && test -f /proc/$shell_pid/winpid
+	then
+		# In Git for Windows, Bash (actually, the MSYS2 runtime) has a
+		# different idea of PIDs than git.exe (actually Windows). Use
+		# the Windows PID in this case.
+		shell_pid=$(cat /proc/$shell_pid/winpid)
+	fi &&
+	printf "%d %s" "$shell_pid" "$hostname" >.git/gc.pid &&
 
 	# our gc should exit zero without doing anything
 	run_and_wait_for_auto_gc &&
diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index e285686..6aeeb27 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -1702,7 +1702,7 @@
 
 test_expect_success 'recursive tagging should give advice' '
 	sed -e "s/|$//" <<-EOF >expect &&
-	hint: You have created a nested tag. The object referred to by your new is
+	hint: You have created a nested tag. The object referred to by your new tag is
 	hint: already a tag. If you meant to tag the object that it points to, use:
 	hint: |
 	hint: 	git tag -f nested annotated-v4.0^{}
diff --git a/t/t7519-status-fsmonitor.sh b/t/t7519-status-fsmonitor.sh
index 3e0a61d..81a375f 100755
--- a/t/t7519-status-fsmonitor.sh
+++ b/t/t7519-status-fsmonitor.sh
@@ -346,4 +346,12 @@
 	test_cmp before after
 '
 
+test_expect_success 'discard_index() also discards fsmonitor info' '
+	test_config core.fsmonitor "$TEST_DIRECTORY/t7519/fsmonitor-all" &&
+	test_might_fail git update-index --refresh &&
+	test-tool read-cache --print-and-refresh=tracked 2 >actual &&
+	printf "tracked is%s up to date\n" "" " not" >expect &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t7610-mergetool.sh b/t/t7610-mergetool.sh
index a9fb971..5b61c10 100755
--- a/t/t7610-mergetool.sh
+++ b/t/t7610-mergetool.sh
@@ -130,14 +130,55 @@
 	test_when_finished "git reset --hard" &&
 	git checkout -b test$test_count branch1 &&
 	git submodule update -N &&
-	test_must_fail git merge master >/dev/null 2>&1 &&
-	( yes "" | git mergetool both >/dev/null 2>&1 ) &&
+	test_must_fail git merge master &&
+	( yes "" | git mergetool both ) &&
 	( yes "" | git mergetool file1 file1 ) &&
-	( yes "" | git mergetool file2 "spaced name" >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file12 >/dev/null 2>&1 ) &&
-	( yes "l" | git mergetool submod >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool file2 "spaced name" ) &&
+	( yes "" | git mergetool subdir/file3 ) &&
+	( yes "d" | git mergetool file11 ) &&
+	( yes "d" | git mergetool file12 ) &&
+	( yes "l" | git mergetool submod ) &&
+	test "$(cat file1)" = "master updated" &&
+	test "$(cat file2)" = "master new" &&
+	test "$(cat subdir/file3)" = "master new sub" &&
+	test "$(cat submod/bar)" = "branch1 submodule" &&
+	git commit -m "branch1 resolved with mergetool"
+'
+
+test_expect_success 'gui mergetool' '
+	test_config merge.guitool myguitool &&
+	test_config mergetool.myguitool.cmd "(printf \"gui \" && cat \"\$REMOTE\") >\"\$MERGED\"" &&
+	test_config mergetool.myguitool.trustExitCode true &&
+	test_when_finished "git reset --hard" &&
+	git checkout -b test$test_count branch1 &&
+	git submodule update -N &&
+	test_must_fail git merge master &&
+	( yes "" | git mergetool --gui both ) &&
+	( yes "" | git mergetool -g file1 file1 ) &&
+	( yes "" | git mergetool --gui file2 "spaced name" ) &&
+	( yes "" | git mergetool --gui subdir/file3 ) &&
+	( yes "d" | git mergetool --gui file11 ) &&
+	( yes "d" | git mergetool --gui file12 ) &&
+	( yes "l" | git mergetool --gui submod ) &&
+	test "$(cat file1)" = "gui master updated" &&
+	test "$(cat file2)" = "gui master new" &&
+	test "$(cat subdir/file3)" = "gui master new sub" &&
+	test "$(cat submod/bar)" = "branch1 submodule" &&
+	git commit -m "branch1 resolved with mergetool"
+'
+
+test_expect_success 'gui mergetool without merge.guitool set falls back to merge.tool' '
+	test_when_finished "git reset --hard" &&
+	git checkout -b test$test_count branch1 &&
+	git submodule update -N &&
+	test_must_fail git merge master &&
+	( yes "" | git mergetool --gui both ) &&
+	( yes "" | git mergetool -g file1 file1 ) &&
+	( yes "" | git mergetool --gui file2 "spaced name" ) &&
+	( yes "" | git mergetool --gui subdir/file3 ) &&
+	( yes "d" | git mergetool --gui file11 ) &&
+	( yes "d" | git mergetool --gui file12 ) &&
+	( yes "l" | git mergetool --gui submod ) &&
 	test "$(cat file1)" = "master updated" &&
 	test "$(cat file2)" = "master new" &&
 	test "$(cat subdir/file3)" = "master new sub" &&
@@ -153,15 +194,15 @@
 	# test_when_finished is LIFO.)
 	test_config core.autocrlf true &&
 	git checkout -b test$test_count branch1 &&
-	test_must_fail git merge master >/dev/null 2>&1 &&
-	( yes "" | git mergetool file1 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool file2 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool "spaced name" >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool both >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file12 >/dev/null 2>&1 ) &&
-	( yes "r" | git mergetool submod >/dev/null 2>&1 ) &&
+	test_must_fail git merge master &&
+	( yes "" | git mergetool file1 ) &&
+	( yes "" | git mergetool file2 ) &&
+	( yes "" | git mergetool "spaced name" ) &&
+	( yes "" | git mergetool both ) &&
+	( yes "" | git mergetool subdir/file3 ) &&
+	( yes "d" | git mergetool file11 ) &&
+	( yes "d" | git mergetool file12 ) &&
+	( yes "r" | git mergetool submod ) &&
 	test "$(printf x | cat file1 -)" = "$(printf "master updated\r\nx")" &&
 	test "$(printf x | cat file2 -)" = "$(printf "master new\r\nx")" &&
 	test "$(printf x | cat subdir/file3 -)" = "$(printf "master new sub\r\nx")" &&
@@ -176,8 +217,8 @@
 	git submodule update -N &&
 	(
 		cd subdir &&
-		test_must_fail git merge master >/dev/null 2>&1 &&
-		( yes "" | git mergetool file3 >/dev/null 2>&1 ) &&
+		test_must_fail git merge master &&
+		( yes "" | git mergetool file3 ) &&
 		test "$(cat file3)" = "master new sub"
 	)
 '
@@ -188,14 +229,14 @@
 	git submodule update -N &&
 	(
 		cd subdir &&
-		test_must_fail git merge master >/dev/null 2>&1 &&
-		( yes "" | git mergetool file3 >/dev/null 2>&1 ) &&
-		( yes "" | git mergetool ../file1 >/dev/null 2>&1 ) &&
-		( yes "" | git mergetool ../file2 ../spaced\ name >/dev/null 2>&1 ) &&
-		( yes "" | git mergetool ../both >/dev/null 2>&1 ) &&
-		( yes "d" | git mergetool ../file11 >/dev/null 2>&1 ) &&
-		( yes "d" | git mergetool ../file12 >/dev/null 2>&1 ) &&
-		( yes "l" | git mergetool ../submod >/dev/null 2>&1 ) &&
+		test_must_fail git merge master &&
+		( yes "" | git mergetool file3 ) &&
+		( yes "" | git mergetool ../file1 ) &&
+		( yes "" | git mergetool ../file2 ../spaced\ name ) &&
+		( yes "" | git mergetool ../both ) &&
+		( yes "d" | git mergetool ../file11 ) &&
+		( yes "d" | git mergetool ../file12 ) &&
+		( yes "l" | git mergetool ../submod ) &&
 		test "$(cat ../file1)" = "master updated" &&
 		test "$(cat ../file2)" = "master new" &&
 		test "$(cat ../submod/bar)" = "branch1 submodule" &&
@@ -209,9 +250,9 @@
 	git submodule update -N &&
 	test_must_fail git merge master &&
 	test -n "$(git ls-files -u)" &&
-	( yes "d" | git mergetool file11 >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file12 >/dev/null 2>&1 ) &&
-	( yes "l" | git mergetool submod >/dev/null 2>&1 ) &&
+	( yes "d" | git mergetool file11 ) &&
+	( yes "d" | git mergetool file12 ) &&
+	( yes "l" | git mergetool submod ) &&
 	output="$(git mergetool --no-prompt)" &&
 	test "$output" = "No files need merging"
 '
@@ -259,9 +300,9 @@
 	rm -rf .git/rr-cache &&
 	git checkout -b test$test_count branch1 &&
 	git submodule update -N &&
-	test_must_fail git merge master >/dev/null 2>&1 &&
-	( yes "l" | git mergetool --no-prompt submod >/dev/null 2>&1 ) &&
-	( yes "d" "d" | git mergetool --no-prompt >/dev/null 2>&1 ) &&
+	test_must_fail git merge master &&
+	( yes "l" | git mergetool --no-prompt submod ) &&
+	( yes "d" "d" | git mergetool --no-prompt ) &&
 	git submodule update -N &&
 	output="$(yes "n" | git mergetool --no-prompt)" &&
 	test "$output" = "No files need merging"
@@ -369,9 +410,9 @@
 	git checkout -b test$test_count.a test$test_count &&
 	test_must_fail git merge master &&
 	test -n "$(git ls-files -u)" &&
-	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool both >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 file12 >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 ) &&
+	( yes "" | git mergetool both ) &&
+	( yes "d" | git mergetool file11 file12 ) &&
 	( yes "r" | git mergetool submod ) &&
 	rmdir submod && mv submod-movedaside submod &&
 	test "$(cat submod/bar)" = "branch1 submodule" &&
@@ -386,9 +427,9 @@
 	git submodule update -N &&
 	test_must_fail git merge master &&
 	test -n "$(git ls-files -u)" &&
-	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool both >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 file12 >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 ) &&
+	( yes "" | git mergetool both ) &&
+	( yes "d" | git mergetool file11 file12 ) &&
 	( yes "l" | git mergetool submod ) &&
 	test ! -e submod &&
 	output="$(git mergetool --no-prompt)" &&
@@ -400,9 +441,9 @@
 	git submodule update -N &&
 	test_must_fail git merge test$test_count &&
 	test -n "$(git ls-files -u)" &&
-	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool both >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 file12 >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 ) &&
+	( yes "" | git mergetool both ) &&
+	( yes "d" | git mergetool file11 file12 ) &&
 	( yes "r" | git mergetool submod ) &&
 	test ! -e submod &&
 	test -d submod.orig &&
@@ -416,9 +457,9 @@
 	git submodule update -N &&
 	test_must_fail git merge test$test_count &&
 	test -n "$(git ls-files -u)" &&
-	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool both >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 file12 >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 ) &&
+	( yes "" | git mergetool both ) &&
+	( yes "d" | git mergetool file11 file12 ) &&
 	( yes "l" | git mergetool submod ) &&
 	test "$(cat submod/bar)" = "master submodule" &&
 	git submodule update -N &&
@@ -440,9 +481,9 @@
 	git checkout -b test$test_count.a branch1 &&
 	test_must_fail git merge master &&
 	test -n "$(git ls-files -u)" &&
-	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool both >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 file12 >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 ) &&
+	( yes "" | git mergetool both ) &&
+	( yes "d" | git mergetool file11 file12 ) &&
 	( yes "r" | git mergetool submod ) &&
 	rmdir submod && mv submod-movedaside submod &&
 	test "$(cat submod/bar)" = "branch1 submodule" &&
@@ -456,9 +497,9 @@
 	git checkout -b test$test_count.b test$test_count &&
 	test_must_fail git merge master &&
 	test -n "$(git ls-files -u)" &&
-	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool both >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 file12 >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 ) &&
+	( yes "" | git mergetool both ) &&
+	( yes "d" | git mergetool file11 file12 ) &&
 	( yes "l" | git mergetool submod ) &&
 	git submodule update -N &&
 	test "$(cat submod)" = "not a submodule" &&
@@ -472,9 +513,9 @@
 	git submodule update -N &&
 	test_must_fail git merge test$test_count &&
 	test -n "$(git ls-files -u)" &&
-	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool both >/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 file12 >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 ) &&
+	( yes "" | git mergetool both ) &&
+	( yes "d" | git mergetool file11 file12 ) &&
 	( yes "r" | git mergetool submod ) &&
 	test -d submod.orig &&
 	git submodule update -N &&
@@ -488,9 +529,9 @@
 	git submodule update -N &&
 	test_must_fail git merge test$test_count &&
 	test -n "$(git ls-files -u)" &&
-	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 >/dev/null 2>&1 ) &&
-	( yes "" | git mergetool both>/dev/null 2>&1 ) &&
-	( yes "d" | git mergetool file11 file12 >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool file1 file2 spaced\ name subdir/file3 ) &&
+	( yes "" | git mergetool both ) &&
+	( yes "d" | git mergetool file11 file12 ) &&
 	( yes "l" | git mergetool submod ) &&
 	test "$(cat submod/bar)" = "master submodule" &&
 	git submodule update -N &&
@@ -543,7 +584,7 @@
 	git add subdir/subdir_module &&
 	git commit -m "change submodule in subdirectory on test$test_count.b" &&
 
-	test_must_fail git merge test$test_count.a >/dev/null 2>&1 &&
+	test_must_fail git merge test$test_count.a &&
 	(
 		cd subdir &&
 		( yes "l" | git mergetool subdir_module )
@@ -554,7 +595,7 @@
 	git reset --hard &&
 	git submodule update -N &&
 
-	test_must_fail git merge test$test_count.a >/dev/null 2>&1 &&
+	test_must_fail git merge test$test_count.a &&
 	( yes "r" | git mergetool subdir/subdir_module ) &&
 	test "$(cat subdir/subdir_module/file15)" = "test$test_count.b" &&
 	git submodule update -N &&
@@ -641,7 +682,7 @@
 	test_config mergetool.myecho.trustExitCode true &&
 	test_must_fail git merge master &&
 	git mergetool --no-prompt --tool myecho -- both >actual &&
-	grep ^\./both_LOCAL_ actual >/dev/null
+	grep ^\./both_LOCAL_ actual
 '
 
 test_lazy_prereq MKTEMP '
@@ -658,8 +699,8 @@
 	test_config mergetool.myecho.trustExitCode true &&
 	test_must_fail git merge master &&
 	git mergetool --no-prompt --tool myecho -- both >actual &&
-	! grep ^\./both_LOCAL_ actual >/dev/null &&
-	grep /both_LOCAL_ actual >/dev/null
+	! grep ^\./both_LOCAL_ actual &&
+	grep /both_LOCAL_ actual
 '
 
 test_expect_success 'diff.orderFile configuration is honored' '
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 480dd06..6bac9ed 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -279,11 +279,27 @@
 	echo branch >expect &&
 	git difftool --no-prompt branch >actual &&
 	test_cmp expect actual &&
+	git difftool --gui --no-prompt branch >actual &&
+	test_cmp expect actual &&
 
 	# set merge.tool to something bogus, diff.tool to test-tool
 	test_config merge.tool bogus-tool &&
 	test_config diff.tool test-tool &&
 	git difftool --no-prompt branch >actual &&
+	test_cmp expect actual &&
+	git difftool --gui --no-prompt branch >actual &&
+	test_cmp expect actual &&
+
+	# set merge.tool, diff.tool to something bogus, merge.guitool to test-tool
+	test_config diff.tool bogus-tool &&
+	test_config merge.guitool test-tool &&
+	git difftool --gui --no-prompt branch >actual &&
+	test_cmp expect actual &&
+
+	# set merge.tool, diff.tool, merge.guitool to something bogus, diff.guitool to test-tool
+	test_config merge.guitool bogus-tool &&
+	test_config diff.guitool test-tool &&
+	git difftool --gui --no-prompt branch >actual &&
 	test_cmp expect actual
 '
 
@@ -715,4 +731,12 @@
 	test_cmp expect actual
 '
 
+test_expect_success 'difftool --gui, --tool and --extcmd are mutually exclusive' '
+	difftool_test_setup &&
+	test_must_fail git difftool --gui --tool=test-tool &&
+	test_must_fail git difftool --gui --extcmd=cat &&
+	test_must_fail git difftool --tool=test-tool --extcmd=cat &&
+	test_must_fail git difftool --gui --tool=test-tool --extcmd=cat
+'
+
 test_done
diff --git a/upload-pack.c b/upload-pack.c
index d2ea5eb..2429891 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -1069,6 +1069,8 @@
 		allow_ref_in_want = git_config_bool(var, value);
 	} else if (!strcmp("uploadpack.allowsidebandall", var)) {
 		allow_sideband_all = git_config_bool(var, value);
+	} else if (!strcmp("core.precomposeunicode", var)) {
+		precomposed_unicode = git_config_bool(var, value);
 	}
 
 	if (current_config_scope() != CONFIG_SCOPE_REPO) {
diff --git a/wt-status.c b/wt-status.c
index e065558..d2a1bec 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1215,7 +1215,9 @@
 	int i;
 
 	if (starts_with(line->buf, "exec ") ||
-	    starts_with(line->buf, "x "))
+	    starts_with(line->buf, "x ") ||
+	    starts_with(line->buf, "label ") ||
+	    starts_with(line->buf, "l "))
 		return;
 
 	split = strbuf_split_max(line, ' ', 3);