Merge maint branch for tracking l10n updates of git stable version

Use master branch to track l10n updates for git next release, while
use maint branch to track l10n updates for git stable version.

40 files changed, 779 insertions, 213 deletions

diff --git a/Documentation/RelNotes/1.7.10.1.txt b/Documentation/RelNotes/1.7.10.1.txt
new file mode 100644
index 0000000000..36b8deef19
--- /dev/null
+++ b/Documentation/RelNotes/1.7.10.1.txt
@@ -0,0 +1,50 @@
+Git v1.7.10.1 Release Notes
+===========================
+
+Fixes since v1.7.10
+-------------------
+
+ * "git add -p" is not designed to deal with unmerged paths but did
+   not exclude them and tried to apply funny patches only to fail.
+
+ * When PATH contains an unreadable directory, alias expansion code
+   did not kick in, and failed with an error that said "git-subcmd"
+   was not found.
+
+ * "git clean -d -f" (not "-d -f -f") is supposed to protect nested
+   working trees of independent git repositories that exist in the
+   current project working tree from getting removed, but the
+   protection applied only to such working trees that are at the
+   top-level of the current project by mistake.
+
+ * "git commit --author=$name" did not tell the name that was being
+   recorded in the resulting commit to hooks, even though it does do
+   so when the end user overrode the authorship via the
+   "GIT_AUTHOR_NAME" environment variable.
+
+ * When "git commit --template F" errors out because the user did not
+   touch the message, it claimed that it aborts due to "empty
+   message", which was utterly wrong.
+
+ * The regexp configured with diff.wordregex was incorrectly reused
+   across files.
+
+ * An age-old corner case bug in combine diff (only triggered with -U0
+   and the hunk at the beginning of the file needs to be shown) has
+   been fixed.
+
+ * Rename detection logic used to match two empty files as renames
+   during merge-recursive, leading to unnatural mismerges.
+
+ * Running "notes merge --commit" failed to perform correctly when run
+   from any directory inside $GIT_DIR/.  When "notes merge" stops with
+   conflicts, $GIT_DIR/NOTES_MERGE_WORKTREE is the place a user edits
+   to resolve it.
+
+ * The 'push to upstream' implementation was broken in some corner
+   cases. "git push $there" without refspec, when the current branch
+   is set to push to a remote different from $there, used to push to
+   $there using the upstream information to a remote unreleated to
+   $there.
+
+Also contains minor fixes and documentation updates.
diff --git a/Documentation/RelNotes/1.7.7.7.txt b/Documentation/RelNotes/1.7.7.7.txt
new file mode 100644
index 0000000000..e79118d063
--- /dev/null
+++ b/Documentation/RelNotes/1.7.7.7.txt
@@ -0,0 +1,13 @@
+Git v1.7.7.7 Release Notes
+==========================
+
+Fixes since v1.7.7.6
+--------------------
+
+ * An error message from 'git bundle' had an unmatched single quote pair in it.
+
+ * 'git diff --histogram' option was not described.
+
+ * 'git imap-send' carried an unused dead code.
+
+Also contains minor fixes and documentation updates.
diff --git a/Documentation/RelNotes/1.7.8.6.txt b/Documentation/RelNotes/1.7.8.6.txt
new file mode 100644
index 0000000000..d9bf2b741a
--- /dev/null
+++ b/Documentation/RelNotes/1.7.8.6.txt
@@ -0,0 +1,22 @@
+Git v1.7.8.6 Release Notes
+==========================
+
+Fixes since v1.7.8.5
+--------------------
+
+ * An error message from 'git bundle' had an unmatched single quote pair in it.
+
+ * 'git diff --histogram' option was not described.
+
+ * Documentation for 'git rev-list' had minor formatting errors.
+
+ * 'git imap-send' carried an unused dead code.
+
+ * The way 'git fetch' implemented its connectivity check over
+   received objects was overly pessimistic, and wasted a lot of
+   cycles.
+
+ * Various minor backports of fixes from the 'master' and the 'maint'
+   branch.
+
+Also contains minor fixes and documentation updates.
diff --git a/Documentation/RelNotes/1.7.9.7.txt b/Documentation/RelNotes/1.7.9.7.txt
new file mode 100644
index 0000000000..59667d0f2a
--- /dev/null
+++ b/Documentation/RelNotes/1.7.9.7.txt
@@ -0,0 +1,13 @@
+Git v1.7.9.7 Release Notes
+==========================
+
+Fixes since v1.7.9.6
+--------------------
+
+ * An error message from 'git bundle' had an unmatched single quote pair in it.
+
+ * The way 'git fetch' implemented its connectivity check over
+   received objects was overly pessimistic, and wasted a lot of
+   cycles.
+
+Also contains minor fixes and documentation updates.
diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 5cc84a1391..68abfcacca 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -132,11 +132,14 @@ OPTIONS
 
 -t <file>::
 --template=<file>::
-	Use the contents of the given file as the initial version
-	of the commit message. The editor is invoked and you can
-	make subsequent changes. If a message is specified using
-	the `-m` or `-F` options, this option has no effect. This
-	overrides the `commit.template` configuration variable.
+	When editing the commit message, start the editor with the
+	contents in the given file.  The `commit.template` configuration
+	variable is often used to give this option implicitly to the
+	command.  This mechanism can be used by projects that want to
+	guide participants with some hints on what to write in the message
+	in what order.  If the user exits the editor without editing the
+	message, the commit is aborted.  This has no effect when a message
+	is given by other means, e.g. with the `-m` or `-F` options.
 
 -s::
 --signoff::
diff --git a/Documentation/git.txt b/Documentation/git.txt
index ca85d1d210..c2b523c589 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -49,9 +49,10 @@ Documentation for older releases are available here:
 * release notes for
   link:RelNotes/1.7.10.txt[1.7.10].
 
-* link:v1.7.9.6/git.html[documentation for release 1.7.9.6]
+* link:v1.7.9.7/git.html[documentation for release 1.7.9.7]
 
 * release notes for
+  link:RelNotes/1.7.9.7.txt[1.7.9.7],
   link:RelNotes/1.7.9.6.txt[1.7.9.6],
   link:RelNotes/1.7.9.5.txt[1.7.9.5],
   link:RelNotes/1.7.9.4.txt[1.7.9.4],
@@ -60,9 +61,10 @@ Documentation for older releases are available here:
   link:RelNotes/1.7.9.1.txt[1.7.9.1],
   link:RelNotes/1.7.9.txt[1.7.9].
 
-* link:v1.7.8.5/git.html[documentation for release 1.7.8.5]
+* link:v1.7.8.6/git.html[documentation for release 1.7.8.6]
 
 * release notes for
+  link:RelNotes/1.7.8.6.txt[1.7.8.6],
   link:RelNotes/1.7.8.5.txt[1.7.8.5],
   link:RelNotes/1.7.8.4.txt[1.7.8.4],
   link:RelNotes/1.7.8.3.txt[1.7.8.3],
@@ -70,9 +72,10 @@ Documentation for older releases are available here:
   link:RelNotes/1.7.8.1.txt[1.7.8.1],
   link:RelNotes/1.7.8.txt[1.7.8].
 
-* link:v1.7.7.6/git.html[documentation for release 1.7.7.6]
+* link:v1.7.7.7/git.html[documentation for release 1.7.7.7]
 
 * release notes for
+  link:RelNotes/1.7.7.7.txt[1.7.7.7],
   link:RelNotes/1.7.7.6.txt[1.7.7.6],
   link:RelNotes/1.7.7.5.txt[1.7.7.5],
   link:RelNotes/1.7.7.4.txt[1.7.7.4],
diff --git a/RelNotes b/RelNotes
index 2c2a169555..46474cc708 120000
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/1.7.10.txt
\ No newline at end of file
+Documentation/RelNotes/1.7.10.1.txt
\ No newline at end of file
diff --git a/builtin/commit.c b/builtin/commit.c
index 3714582e19..b257ae8774 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -533,9 +533,20 @@ static int is_a_merge(const struct commit *current_head)
 
 static const char sign_off_header[] = "Signed-off-by: ";
 
+static void export_one(const char *var, const char *s, const char *e, int hack)
+{
+	struct strbuf buf = STRBUF_INIT;
+	if (hack)
+		strbuf_addch(&buf, hack);
+	strbuf_addf(&buf, "%.*s", (int)(e - s), s);
+	setenv(var, buf.buf, 1);
+	strbuf_release(&buf);
+}
+
 static void determine_author_info(struct strbuf *author_ident)
 {
 	char *name, *email, *date;
+	struct ident_split author;
 
 	name = getenv("GIT_AUTHOR_NAME");
 	email = getenv("GIT_AUTHOR_EMAIL");
@@ -585,6 +596,11 @@ static void determine_author_info(struct strbuf *author_ident)
 		date = force_date;
 	strbuf_addstr(author_ident, fmt_ident(name, email, date,
 					      IDENT_ERROR_ON_NO_NAME));
+	if (!split_ident_line(&author, author_ident->buf, author_ident->len)) {
+		export_one("GIT_AUTHOR_NAME", author.name_begin, author.name_end, 0);
+		export_one("GIT_AUTHOR_EMAIL", author.mail_begin, author.mail_end, 0);
+		export_one("GIT_AUTHOR_DATE", author.date_begin, author.tz_end, '@');
+	}
 }
 
 static int ends_rfc2822_footer(struct strbuf *sb)
@@ -652,6 +668,9 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	int ident_shown = 0;
 	int clean_message_contents = (cleanup_mode != CLEANUP_NONE);
 
+	/* This checks and barfs if author is badly specified */
+	determine_author_info(author_ident);
+
 	if (!no_verify && run_hook(index_file, "pre-commit", NULL))
 		return 0;
 
@@ -771,9 +790,6 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 
 	strbuf_release(&sb);
 
-	/* This checks and barfs if author is badly specified */
-	determine_author_info(author_ident);
-
 	/* This checks if committer ident is explicitly given */
 	strbuf_addstr(&committer_ident, git_committer_info(0));
 	if (use_editor && include_status) {
@@ -905,27 +921,10 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	return 1;
 }
 
-/*
- * Find out if the message in the strbuf contains only whitespace and
- * Signed-off-by lines.
- */
-static int message_is_empty(struct strbuf *sb)
+static int rest_is_empty(struct strbuf *sb, int start)
 {
-	struct strbuf tmpl = STRBUF_INIT;
+	int i, eol;
 	const char *nl;
-	int eol, i, start = 0;
-
-	if (cleanup_mode == CLEANUP_NONE && sb->len)
-		return 0;
-
-	/* See if the template is just a prefix of the message. */
-	if (template_file && strbuf_read_file(&tmpl, template_file, 0) > 0) {
-		stripspace(&tmpl, cleanup_mode == CLEANUP_ALL);
-		if (start + tmpl.len <= sb->len &&
-		    memcmp(tmpl.buf, sb->buf + start, tmpl.len) == 0)
-			start += tmpl.len;
-	}
-	strbuf_release(&tmpl);
 
 	/* Check if the rest is just whitespace and Signed-of-by's. */
 	for (i = start; i < sb->len; i++) {
@@ -948,6 +947,40 @@ static int message_is_empty(struct strbuf *sb)
 	return 1;
 }
 
+/*
+ * Find out if the message in the strbuf contains only whitespace and
+ * Signed-off-by lines.
+ */
+static int message_is_empty(struct strbuf *sb)
+{
+	if (cleanup_mode == CLEANUP_NONE && sb->len)
+		return 0;
+	return rest_is_empty(sb, 0);
+}
+
+/*
+ * See if the user edited the message in the editor or left what
+ * was in the template intact
+ */
+static int template_untouched(struct strbuf *sb)
+{
+	struct strbuf tmpl = STRBUF_INIT;
+	char *start;
+
+	if (cleanup_mode == CLEANUP_NONE && sb->len)
+		return 0;
+
+	if (!template_file || strbuf_read_file(&tmpl, template_file, 0) <= 0)
+		return 0;
+
+	stripspace(&tmpl, cleanup_mode == CLEANUP_ALL);
+	start = (char *)skip_prefix(sb->buf, tmpl.buf);
+	if (!start)
+		start = sb->buf;
+	strbuf_release(&tmpl);
+	return rest_is_empty(sb, start - sb->buf);
+}
+
 static const char *find_author_by_nickname(const char *name)
 {
 	struct rev_info revs;
@@ -1055,6 +1088,8 @@ static int parse_and_validate_options(int argc, const char *argv[],
 		die(_("Only one of -c/-C/-F/--fixup can be used."));
 	if (message.len && f > 0)
 		die((_("Option -m cannot be combined with -c/-C/-F/--fixup.")));
+	if (f || message.len)
+		template_file = NULL;
 	if (edit_message)
 		use_message = edit_message;
 	if (amend && !use_message && !fixup_message)
@@ -1494,6 +1529,11 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 
 	if (cleanup_mode != CLEANUP_NONE)
 		stripspace(&sb, cleanup_mode == CLEANUP_ALL);
+	if (template_untouched(&sb) && !allow_empty_message) {
+		rollback_index_files();
+		fprintf(stderr, _("Aborting commit; you did not edit the message.\n"));
+		exit(1);
+	}
 	if (message_is_empty(&sb) && !allow_empty_message) {
 		rollback_index_files();
 		fprintf(stderr, _("Aborting commit due to empty commit message.\n"));
diff --git a/builtin/diff.c b/builtin/diff.c
index 424c815f9b..9069dc41be 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -327,7 +327,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 				add_head_to_pending(&rev);
 				if (!rev.pending.nr) {
 					struct tree *tree;
-					tree = lookup_tree((const unsigned char*)EMPTY_TREE_SHA1_BIN);
+					tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
 					add_pending_object(&rev, &tree->object, "HEAD");
 				}
 				break;
diff --git a/builtin/push.c b/builtin/push.c
index d315475f16..b6c0fee4c6 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -65,6 +65,16 @@ static void set_refspecs(const char **refs, int nr)
 	}
 }
 
+static int push_url_of_remote(struct remote *remote, const char ***url_p)
+{
+	if (remote->pushurl_nr) {
+		*url_p = remote->pushurl;
+		return remote->pushurl_nr;
+	}
+	*url_p = remote->url;
+	return remote->url_nr;
+}
+
 static void setup_push_upstream(struct remote *remote)
 {
 	struct strbuf refspec = STRBUF_INIT;
@@ -76,7 +86,7 @@ static void setup_push_upstream(struct remote *remote)
 		    "\n"
 		    "    git push %s HEAD:<name-of-remote-branch>\n"),
 		    remote->name);
-	if (!branch->merge_nr || !branch->merge)
+	if (!branch->merge_nr || !branch->merge || !branch->remote_name)
 		die(_("The current branch %s has no upstream branch.\n"
 		    "To push the current branch and set the remote as upstream, use\n"
 		    "\n"
@@ -87,6 +97,12 @@ static void setup_push_upstream(struct remote *remote)
 	if (branch->merge_nr != 1)
 		die(_("The current branch %s has multiple upstream branches, "
 		    "refusing to push."), branch->name);
+	if (strcmp(branch->remote_name, remote->name))
+		die(_("You are pushing to remote '%s', which is not the upstream of\n"
+		      "your current branch '%s', without telling me what to push\n"
+		      "to update which remote branch."),
+		    remote->name, branch->name);
+
 	strbuf_addf(&refspec, "%s:%s", branch->name, branch->merge[0]->src);
 	add_refspec(refspec.buf);
 }
@@ -196,13 +212,7 @@ static int do_push(const char *repo, int flags)
 			setup_default_push_refspecs(remote);
 	}
 	errs = 0;
-	if (remote->pushurl_nr) {
-		url = remote->pushurl;
-		url_nr = remote->pushurl_nr;
-	} else {
-		url = remote->url;
-		url_nr = remote->url_nr;
-	}
+	url_nr = push_url_of_remote(remote, &url);
 	if (url_nr) {
 		for (i = 0; i < url_nr; i++) {
 			struct transport *transport =
diff --git a/bundle.c b/bundle.c
index d9cfd90534..27ab32e431 100644
--- a/bundle.c
+++ b/bundle.c
@@ -289,7 +289,7 @@ int create_bundle(struct bundle_header *header, const char *path,
 	argc = setup_revisions(argc, argv, &revs, NULL);
 
 	if (argc > 1)
-		return error("unrecognized argument: %s'", argv[1]);
+		return error("unrecognized argument: %s", argv[1]);
 
 	object_array_remove_duplicates(&revs.pending);
 
diff --git a/cache.h b/cache.h
index e5e1aa4e15..5e6eef9b4d 100644
--- a/cache.h
+++ b/cache.h
@@ -708,6 +708,19 @@ static inline void hashclr(unsigned char *hash)
 #define EMPTY_TREE_SHA1_BIN \
 	 ((const unsigned char *) EMPTY_TREE_SHA1_BIN_LITERAL)
 
+#define EMPTY_BLOB_SHA1_HEX \
+	"e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"
+#define EMPTY_BLOB_SHA1_BIN_LITERAL \
+	"\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
+	"\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
+#define EMPTY_BLOB_SHA1_BIN \
+	((const unsigned char *) EMPTY_BLOB_SHA1_BIN_LITERAL)
+
+static inline int is_empty_blob_sha1(const unsigned char *sha1)
+{
+	return !hashcmp(sha1, EMPTY_BLOB_SHA1_BIN);
+}
+
 int git_mkstemp(char *path, size_t n, const char *template);
 
 int git_mkstemps(char *path, size_t n, const char *template, int suffix_len);
@@ -928,6 +941,22 @@ extern const char *fmt_name(const char *name, const char *email);
 extern const char *git_editor(void);
 extern const char *git_pager(int stdout_is_tty);
 
+struct ident_split {
+	const char *name_begin;
+	const char *name_end;
+	const char *mail_begin;
+	const char *mail_end;
+	const char *date_begin;
+	const char *date_end;
+	const char *tz_begin;
+	const char *tz_end;
+};
+/*
+ * Signals an success with 0, but time part of the result may be NULL
+ * if the input lacks timestamp and zone
+ */
+extern int split_ident_line(struct ident_split *, const char *, int);
+
 struct checkout {
 	const char *base_dir;
 	int base_dir_len;
@@ -1276,4 +1305,6 @@ extern struct startup_info *startup_info;
 /* builtin/merge.c */
 int checkout_fast_forward(const unsigned char *from, const unsigned char *to);
 
+int sane_execvp(const char *file, char *const argv[]);
+
 #endif /* CACHE_H */
diff --git a/combine-diff.c b/combine-diff.c
index a2e8dcf855..9786680368 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -423,7 +423,7 @@ static int make_hunks(struct sline *sline, unsigned long cnt,
 						     hunk_begin, j);
 				la = (la + context < cnt + 1) ?
 					(la + context) : cnt + 1;
-				while (j <= --la) {
+				while (la && j <= --la) {
 					if (sline[la].flag & mark) {
 						contin = 1;
 						break;
diff --git a/compat/mingw.c b/compat/mingw.c
index a0ac487c0c..afc892d6b1 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1003,7 +1003,7 @@ static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
 	}
 }
 
-void mingw_execvp(const char *cmd, char *const *argv)
+int mingw_execvp(const char *cmd, char *const *argv)
 {
 	char **path = get_path_split();
 	char *prog = path_lookup(cmd, path, 0);
@@ -1015,11 +1015,13 @@ void mingw_execvp(const char *cmd, char *const *argv)
 		errno = ENOENT;
 
 	free_path_split(path);
+	return -1;
 }
 
-void mingw_execv(const char *cmd, char *const *argv)
+int mingw_execv(const char *cmd, char *const *argv)
 {
 	mingw_execve(cmd, argv, environ);
+	return -1;
 }
 
 int mingw_kill(pid_t pid, int sig)
diff --git a/compat/mingw.h b/compat/mingw.h
index 0ff1e04812..ef5b15014e 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -274,9 +274,9 @@ int mingw_utime(const char *file_name, const struct utimbuf *times);
 pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env,
 		     const char *dir,
 		     int fhin, int fhout, int fherr);
-void mingw_execvp(const char *cmd, char *const *argv);
+int mingw_execvp(const char *cmd, char *const *argv);
 #define execvp mingw_execvp
-void mingw_execv(const char *cmd, char *const *argv);
+int mingw_execv(const char *cmd, char *const *argv);
 #define execv mingw_execv
 
 static inline unsigned int git_ntohl(unsigned int x)
diff --git a/diff.c b/diff.c
index 377ec1ea4c..0dea484ee8 100644
--- a/diff.c
+++ b/diff.c
@@ -989,10 +989,74 @@ static void diff_words_flush(struct emit_callback *ecbdata)
 		diff_words_show(ecbdata->diff_words);
 }
 
+static void diff_filespec_load_driver(struct diff_filespec *one)
+{
+	/* Use already-loaded driver */
+	if (one->driver)
+		return;
+
+	if (S_ISREG(one->mode))
+		one->driver = userdiff_find_by_path(one->path);
+
+	/* Fallback to default settings */
+	if (!one->driver)
+		one->driver = userdiff_find_by_name("default");
+}
+
+static const char *userdiff_word_regex(struct diff_filespec *one)
+{
+	diff_filespec_load_driver(one);
+	return one->driver->word_regex;
+}
+
+static void init_diff_words_data(struct emit_callback *ecbdata,
+				 struct diff_options *orig_opts,
+				 struct diff_filespec *one,
+				 struct diff_filespec *two)
+{
+	int i;
+	struct diff_options *o = xmalloc(sizeof(struct diff_options));
+	memcpy(o, orig_opts, sizeof(struct diff_options));
+
+	ecbdata->diff_words =
+		xcalloc(1, sizeof(struct diff_words_data));
+	ecbdata->diff_words->type = o->word_diff;
+	ecbdata->diff_words->opt = o;
+	if (!o->word_regex)
+		o->word_regex = userdiff_word_regex(one);
+	if (!o->word_regex)
+		o->word_regex = userdiff_word_regex(two);
+	if (!o->word_regex)
+		o->word_regex = diff_word_regex_cfg;
+	if (o->word_regex) {
+		ecbdata->diff_words->word_regex = (regex_t *)
+			xmalloc(sizeof(regex_t));
+		if (regcomp(ecbdata->diff_words->word_regex,
+			    o->word_regex,
+			    REG_EXTENDED | REG_NEWLINE))
+			die ("Invalid regular expression: %s",
+			     o->word_regex);
+	}
+	for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
+		if (o->word_diff == diff_words_styles[i].type) {
+			ecbdata->diff_words->style =
+				&diff_words_styles[i];
+			break;
+		}
+	}
+	if (want_color(o->use_color)) {
+		struct diff_words_style *st = ecbdata->diff_words->style;
+		st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
+		st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
+		st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
+	}
+}
+
 static void free_diff_words_data(struct emit_callback *ecbdata)
 {
 	if (ecbdata->diff_words) {
 		diff_words_flush(ecbdata);
+		free (ecbdata->diff_words->opt);
 		free (ecbdata->diff_words->minus.text.ptr);
 		free (ecbdata->diff_words->minus.orig);
 		free (ecbdata->diff_words->plus.text.ptr);
@@ -2061,20 +2125,6 @@ static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *pre
 	emit_binary_diff_body(file, two, one, prefix);
 }
 
-static void diff_filespec_load_driver(struct diff_filespec *one)
-{
-	/* Use already-loaded driver */
-	if (one->driver)
-		return;
-
-	if (S_ISREG(one->mode))
-		one->driver = userdiff_find_by_path(one->path);
-
-	/* Fallback to default settings */
-	if (!one->driver)
-		one->driver = userdiff_find_by_name("default");
-}
-
 int diff_filespec_is_binary(struct diff_filespec *one)
 {
 	if (one->is_binary == -1) {
@@ -2100,12 +2150,6 @@ static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespe
 	return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
 }
 
-static const char *userdiff_word_regex(struct diff_filespec *one)
-{
-	diff_filespec_load_driver(one);
-	return one->driver->word_regex;
-}
-
 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
 {
 	if (!options->a_prefix)
@@ -2292,42 +2336,8 @@ static void builtin_diff(const char *name_a,
 			xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 		else if (!prefixcmp(diffopts, "-u"))
 			xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
-		if (o->word_diff) {
-			int i;
-
-			ecbdata.diff_words =
-				xcalloc(1, sizeof(struct diff_words_data));
-			ecbdata.diff_words->type = o->word_diff;
-			ecbdata.diff_words->opt = o;
-			if (!o->word_regex)
-				o->word_regex = userdiff_word_regex(one);
-			if (!o->word_regex)
-				o->word_regex = userdiff_word_regex(two);
-			if (!o->word_regex)
-				o->word_regex = diff_word_regex_cfg;
-			if (o->word_regex) {
-				ecbdata.diff_words->word_regex = (regex_t *)
-					xmalloc(sizeof(regex_t));
-				if (regcomp(ecbdata.diff_words->word_regex,
-						o->word_regex,
-						REG_EXTENDED | REG_NEWLINE))
-					die ("Invalid regular expression: %s",
-							o->word_regex);
-			}
-			for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
-				if (o->word_diff == diff_words_styles[i].type) {
-					ecbdata.diff_words->style =
-						&diff_words_styles[i];
-					break;
-				}
-			}
-			if (want_color(o->use_color)) {
-				struct diff_words_style *st = ecbdata.diff_words->style;
-				st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
-				st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
-				st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
-			}
-		}
+		if (o->word_diff)
+			init_diff_words_data(&ecbdata, o, one, two);
 		xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
 			      &xpp, &xecfg);
 		if (o->word_diff)
@@ -3136,6 +3146,7 @@ void diff_setup(struct diff_options *options)
 	options->rename_limit = -1;
 	options->dirstat_permille = diff_dirstat_permille_default;
 	options->context = 3;
+	DIFF_OPT_SET(options, RENAME_EMPTY);
 
 	options->change = diff_change;
 	options->add_remove = diff_addremove;
@@ -3506,6 +3517,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	}
 	else if (!strcmp(arg, "--no-renames"))
 		options->detect_rename = 0;
+	else if (!strcmp(arg, "--rename-empty"))
+		DIFF_OPT_SET(options, RENAME_EMPTY);
+	else if (!strcmp(arg, "--no-rename-empty"))
+		DIFF_OPT_CLR(options, RENAME_EMPTY);
 	else if (!strcmp(arg, "--relative"))
 		DIFF_OPT_SET(options, RELATIVE_NAME);
 	else if (!prefixcmp(arg, "--relative=")) {
diff --git a/diff.h b/diff.h
index cb687436a0..dd48eca71d 100644
--- a/diff.h
+++ b/diff.h
@@ -60,7 +60,7 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
 #define DIFF_OPT_SILENT_ON_REMOVE    (1 <<  5)
 #define DIFF_OPT_FIND_COPIES_HARDER  (1 <<  6)
 #define DIFF_OPT_FOLLOW_RENAMES      (1 <<  7)
-/* (1 <<  8) unused */
+#define DIFF_OPT_RENAME_EMPTY        (1 <<  8)
 /* (1 <<  9) unused */
 #define DIFF_OPT_HAS_CHANGES         (1 << 10)
 #define DIFF_OPT_QUICK               (1 << 11)
diff --git a/diffcore-rename.c b/diffcore-rename.c
index f639601c76..216a7a4bbc 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -512,9 +512,15 @@ void diffcore_rename(struct diff_options *options)
 			else if (options->single_follow &&
 				 strcmp(options->single_follow, p->two->path))
 				continue; /* not interested */
+			else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
+				 is_empty_blob_sha1(p->two->sha1))
+				continue;
 			else
 				locate_rename_dst(p->two, 1);
 		}
+		else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
+			 is_empty_blob_sha1(p->one->sha1))
+			continue;
 		else if (!DIFF_PAIR_UNMERGED(p) && !DIFF_FILE_VALID(p->two)) {
 			/*
 			 * If the source is a broken "delete", and
diff --git a/dir.c b/dir.c
index 0a78d00b54..e98760c72d 100644
--- a/dir.c
+++ b/dir.c
@@ -1172,22 +1172,32 @@ int is_empty_dir(const char *path)
 	return ret;
 }
 
-int remove_dir_recursively(struct strbuf *path, int flag)
+static int remove_dir_recurse(struct strbuf *path, int flag, int *kept_up)
 {
 	DIR *dir;
 	struct dirent *e;
-	int ret = 0, original_len = path->len, len;
+	int ret = 0, original_len = path->len, len, kept_down = 0;
 	int only_empty = (flag & REMOVE_DIR_EMPTY_ONLY);
+	int keep_toplevel = (flag & REMOVE_DIR_KEEP_TOPLEVEL);
 	unsigned char submodule_head[20];
 
 	if ((flag & REMOVE_DIR_KEEP_NESTED_GIT) &&
-	    !resolve_gitlink_ref(path->buf, "HEAD", submodule_head))
+	    !resolve_gitlink_ref(path->buf, "HEAD", submodule_head)) {
 		/* Do not descend and nuke a nested git work tree. */
+		if (kept_up)
+			*kept_up = 1;
 		return 0;
+	}
 
+	flag &= ~REMOVE_DIR_KEEP_TOPLEVEL;
 	dir = opendir(path->buf);
-	if (!dir)
-		return rmdir(path->buf);
+	if (!dir) {
+		/* an empty dir could be removed even if it is unreadble */
+		if (!keep_toplevel)
+			return rmdir(path->buf);
+		else
+			return -1;
+	}
 	if (path->buf[original_len - 1] != '/')
 		strbuf_addch(path, '/');
 
@@ -1202,7 +1212,7 @@ int remove_dir_recursively(struct strbuf *path, int flag)
 		if (lstat(path->buf, &st))
 			; /* fall thru */
 		else if (S_ISDIR(st.st_mode)) {
-			if (!remove_dir_recursively(path, only_empty))
+			if (!remove_dir_recurse(path, flag, &kept_down))
 				continue; /* happy */
 		} else if (!only_empty && !unlink(path->buf))
 			continue; /* happy, too */
@@ -1214,11 +1224,22 @@ int remove_dir_recursively(struct strbuf *path, int flag)
 	closedir(dir);
 
 	strbuf_setlen(path, original_len);
-	if (!ret)
+	if (!ret && !keep_toplevel && !kept_down)
 		ret = rmdir(path->buf);
+	else if (kept_up)
+		/*
+		 * report the uplevel that it is not an error that we
+		 * did not rmdir() our directory.
+		 */
+		*kept_up = !ret;
 	return ret;
 }
 
+int remove_dir_recursively(struct strbuf *path, int flag)
+{
+	return remove_dir_recurse(path, flag, NULL);
+}
+
 void setup_standard_excludes(struct dir_struct *dir)
 {
 	const char *path;
diff --git a/dir.h b/dir.h
index dd6947e1d4..58b6fc7c86 100644
--- a/dir.h
+++ b/dir.h
@@ -102,6 +102,7 @@ extern void setup_standard_excludes(struct dir_struct *dir);
 
 #define REMOVE_DIR_EMPTY_ONLY 01
 #define REMOVE_DIR_KEEP_NESTED_GIT 02
+#define REMOVE_DIR_KEEP_TOPLEVEL 04
 extern int remove_dir_recursively(struct strbuf *path, int flag);
 
 /* tries to remove the path with empty directories along it, ignores ENOENT */
diff --git a/exec_cmd.c b/exec_cmd.c
index 171e841531..125fa6fabf 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -134,7 +134,7 @@ int execv_git_cmd(const char **argv) {
 	trace_argv_printf(nargv, "trace: exec:");
 
 	/* execvp() can only ever return if it fails */
-	execvp("git", (char **)nargv);
+	sane_execvp("git", (char **)nargv);
 
 	trace_printf("trace: exec failed: %s\n", strerror(errno));
 
diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index 8f0839d205..d948aa88db 100755
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -268,6 +268,7 @@ sub get_empty_tree {
 # FILE:		is file different from index?
 # INDEX_ADDDEL:	is it add/delete between HEAD and index?
 # FILE_ADDDEL:	is it add/delete between index and file?
+# UNMERGED:	is the path unmerged
 
 sub list_modified {
 	my ($only) = @_;
@@ -318,16 +319,10 @@ sub list_modified {
 		}
 	}
 
-	for (run_cmd_pipe(qw(git diff-files --numstat --summary --), @tracked)) {
+	for (run_cmd_pipe(qw(git diff-files --numstat --summary --raw --), @tracked)) {
 		if (($add, $del, $file) =
 		    /^([-\d]+)	([-\d]+)	(.*)/) {
 			$file = unquote_path($file);
-			if (!exists $data{$file}) {
-				$data{$file} = +{
-					INDEX => 'unchanged',
-					BINARY => 0,
-				};
-			}
 			my ($change, $bin);
 			if ($add eq '-' && $del eq '-') {
 				$change = 'binary';
@@ -346,6 +341,18 @@ sub list_modified {
 			$file = unquote_path($file);
 			$data{$file}{FILE_ADDDEL} = $adddel;
 		}
+		elsif (/^:[0-7]+ [0-7]+ [0-9a-f]+ [0-9a-f]+ (.)	(.*)$/) {
+			$file = unquote_path($2);
+			if (!exists $data{$file}) {
+				$data{$file} = +{
+					INDEX => 'unchanged',
+					BINARY => 0,
+				};
+			}
+			if ($1 eq 'U') {
+				$data{$file}{UNMERGED} = 1;
+			}
+		}
 	}
 
 	for (sort keys %data) {
@@ -1190,6 +1197,10 @@ sub apply_patch_for_checkout_commit {
 
 sub patch_update_cmd {
 	my @all_mods = list_modified($patch_mode_flavour{FILTER});
+	error_msg "ignoring unmerged: $_->{VALUE}\n"
+		for grep { $_->{UNMERGED} } @all_mods;
+	@all_mods = grep { !$_->{UNMERGED} } @all_mods;
+
 	my @mods = grep { !($_->{BINARY}) } @all_mods;
 	my @them;
 
diff --git a/ident.c b/ident.c
index f619619b82..87c697c2b0 100644
--- a/ident.c
+++ b/ident.c
@@ -220,6 +220,74 @@ static int copy(char *buf, size_t size, int offset, const char *src)
 	return offset;
 }
 
+/*
+ * Reverse of fmt_ident(); given an ident line, split the fields
+ * to allow the caller to parse it.
+ * Signal a success by returning 0, but date/tz fields of the result
+ * can still be NULL if the input line only has the name/email part
+ * (e.g. reading from a reflog entry).
+ */
+int split_ident_line(struct ident_split *split, const char *line, int len)
+{
+	const char *cp;
+	size_t span;
+	int status = -1;
+
+	memset(split, 0, sizeof(*split));
+
+	split->name_begin = line;
+	for (cp = line; *cp && cp < line + len; cp++)
+		if (*cp == '<') {
+			split->mail_begin = cp + 1;
+			break;
+		}
+	if (!split->mail_begin)
+		return status;
+
+	for (cp = split->mail_begin - 2; line < cp; cp--)
+		if (!isspace(*cp)) {
+			split->name_end = cp + 1;
+			break;
+		}
+	if (!split->name_end)
+		return status;
+
+	for (cp = split->mail_begin; cp < line + len; cp++)
+		if (*cp == '>') {
+			split->mail_end = cp;
+			break;
+		}
+	if (!split->mail_end)
+		return status;
+
+	for (cp = split->mail_end + 1; cp < line + len && isspace(*cp); cp++)
+		;
+	if (line + len <= cp)
+		goto person_only;
+	split->date_begin = cp;
+	span = strspn(cp, "0123456789");
+	if (!span)
+		goto person_only;
+	split->date_end = split->date_begin + span;
+	for (cp = split->date_end; cp < line + len && isspace(*cp); cp++)
+		;
+	if (line + len <= cp || (*cp != '+' && *cp != '-'))
+		goto person_only;
+	split->tz_begin = cp;
+	span = strspn(cp + 1, "0123456789");
+	if (!span)
+		goto person_only;
+	split->tz_end = split->tz_begin + 1 + span;
+	return 0;
+
+person_only:
+	split->date_begin = NULL;
+	split->date_end = NULL;
+	split->tz_begin = NULL;
+	split->tz_end = NULL;
+	return 0;
+}
+
 static const char *env_hint =
 "\n"
 "*** Please tell me who you are.\n"
diff --git a/merge-recursive.c b/merge-recursive.c
index 6479a60cd1..0fb174359a 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -485,6 +485,7 @@ static struct string_list *get_renames(struct merge_options *o,
 	renames = xcalloc(1, sizeof(struct string_list));
 	diff_setup(&opts);
 	DIFF_OPT_SET(&opts, RECURSIVE);
+	DIFF_OPT_CLR(&opts, RENAME_EMPTY);
 	opts.detect_rename = DIFF_DETECT_RENAME;
 	opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 			    o->diff_rename_limit >= 0 ? o->diff_rename_limit :
@@ -1914,7 +1915,7 @@ int merge_recursive(struct merge_options *o,
 		/* if there is no common ancestor, use an empty tree */
 		struct tree *tree;
 
-		tree = lookup_tree((const unsigned char *)EMPTY_TREE_SHA1_BIN);
+		tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
 		merged_common_ancestors = make_virtual_commit(tree, "ancestor");
 	}
 
diff --git a/notes-merge.c b/notes-merge.c
index fb0832f97d..74aa77ce4b 100644
--- a/notes-merge.c
+++ b/notes-merge.c
@@ -267,7 +267,8 @@ static void check_notes_merge_worktree(struct notes_merge_options *o)
 		 * Must establish NOTES_MERGE_WORKTREE.
 		 * Abort if NOTES_MERGE_WORKTREE already exists
 		 */
-		if (file_exists(git_path(NOTES_MERGE_WORKTREE))) {
+		if (file_exists(git_path(NOTES_MERGE_WORKTREE)) &&
+		    !is_empty_dir(git_path(NOTES_MERGE_WORKTREE))) {
 			if (advice_resolve_conflict)
 				die("You have not concluded your previous "
 				    "notes merge (%s exists).\nPlease, use "
@@ -687,51 +688,60 @@ int notes_merge_commit(struct notes_merge_options *o,
 {
 	/*
 	 * Iterate through files in .git/NOTES_MERGE_WORKTREE and add all
-	 * found notes to 'partial_tree'. Write the updates notes tree to
+	 * found notes to 'partial_tree'. Write the updated notes tree to
 	 * the DB, and commit the resulting tree object while reusing the
 	 * commit message and parents from 'partial_commit'.
 	 * Finally store the new commit object SHA1 into 'result_sha1'.
 	 */
-	struct dir_struct dir;
-	char *path = xstrdup(git_path(NOTES_MERGE_WORKTREE "/"));
-	int path_len = strlen(path), i;
+	DIR *dir;
+	struct dirent *e;
+	struct strbuf path = STRBUF_INIT;
 	char *msg = strstr(partial_commit->buffer, "\n\n");
 	struct strbuf sb_msg = STRBUF_INIT;
+	int baselen;
 
+	strbuf_addstr(&path, git_path(NOTES_MERGE_WORKTREE));
 	if (o->verbosity >= 3)
-		printf("Committing notes in notes merge worktree at %.*s\n",
-			path_len - 1, path);
+		printf("Committing notes in notes merge worktree at %s\n",
+			path.buf);
 
 	if (!msg || msg[2] == '\0')
 		die("partial notes commit has empty message");
 	msg += 2;
 
-	memset(&dir, 0, sizeof(dir));
-	read_directory(&dir, path, path_len, NULL);
-	for (i = 0; i < dir.nr; i++) {
-		struct dir_entry *ent = dir.entries[i];
+	dir = opendir(path.buf);
+	if (!dir)
+		die_errno("could not open %s", path.buf);
+
+	strbuf_addch(&path, '/');
+	baselen = path.len;
+	while ((e = readdir(dir)) != NULL) {
 		struct stat st;
-		const char *relpath = ent->name + path_len;
 		unsigned char obj_sha1[20], blob_sha1[20];
 
-		if (ent->len - path_len != 40 || get_sha1_hex(relpath, obj_sha1)) {
+		if (is_dot_or_dotdot(e->d_name))
+			continue;
+
+		if (strlen(e->d_name) != 40 || get_sha1_hex(e->d_name, obj_sha1)) {
 			if (o->verbosity >= 3)
-				printf("Skipping non-SHA1 entry '%s'\n",
-								ent->name);
+				printf("Skipping non-SHA1 entry '%s%s'\n",
+					path.buf, e->d_name);
 			continue;
 		}
 
+		strbuf_addstr(&path, e->d_name);
 		/* write file as blob, and add to partial_tree */
-		if (stat(ent->name, &st))
-			die_errno("Failed to stat '%s'", ent->name);
-		if (index_path(blob_sha1, ent->name, &st, HASH_WRITE_OBJECT))
-			die("Failed to write blob object from '%s'", ent->name);
+		if (stat(path.buf, &st))
+			die_errno("Failed to stat '%s'", path.buf);
+		if (index_path(blob_sha1, path.buf, &st, HASH_WRITE_OBJECT))
+			die("Failed to write blob object from '%s'", path.buf);
 		if (add_note(partial_tree, obj_sha1, blob_sha1, NULL))
 			die("Failed to add resolved note '%s' to notes tree",
-			    ent->name);
+			    path.buf);
 		if (o->verbosity >= 4)
 			printf("Added resolved note for object %s: %s\n",
 				sha1_to_hex(obj_sha1), sha1_to_hex(blob_sha1));
+		strbuf_setlen(&path, baselen);
 	}
 
 	strbuf_attach(&sb_msg, msg, strlen(msg), strlen(msg) + 1);
@@ -740,20 +750,25 @@ int notes_merge_commit(struct notes_merge_options *o,
 	if (o->verbosity >= 4)
 		printf("Finalized notes merge commit: %s\n",
 			sha1_to_hex(result_sha1));
-	free(path);
+	strbuf_release(&path);
+	closedir(dir);
 	return 0;
 }
 
 int notes_merge_abort(struct notes_merge_options *o)
 {
-	/* Remove .git/NOTES_MERGE_WORKTREE directory and all files within */
+	/*
+	 * Remove all files within .git/NOTES_MERGE_WORKTREE. We do not remove
+	 * the .git/NOTES_MERGE_WORKTREE directory itself, since it might be
+	 * the current working directory of the user.
+	 */
 	struct strbuf buf = STRBUF_INIT;
 	int ret;
 
 	strbuf_addstr(&buf, git_path(NOTES_MERGE_WORKTREE));
 	if (o->verbosity >= 3)
-		printf("Removing notes merge worktree at %s\n", buf.buf);
-	ret = remove_dir_recursively(&buf, 0);
+		printf("Removing notes merge worktree at %s/*\n", buf.buf);
+	ret = remove_dir_recursively(&buf, REMOVE_DIR_KEEP_TOPLEVEL);
 	strbuf_release(&buf);
 	return ret;
 }
diff --git a/pretty.c b/pretty.c
index 8688b8f2d4..f2dee308b8 100644
--- a/pretty.c
+++ b/pretty.c
@@ -531,41 +531,24 @@ static size_t format_person_part(struct strbuf *sb, char part,
 {
 	/* currently all placeholders have same length */
 	const int placeholder_len = 2;
-	int start, end, tz = 0;
+	int tz;
 	unsigned long date = 0;
-	char *ep;
-	const char *name_start, *name_end, *mail_start, *mail_end, *msg_end = msg+len;
 	char person_name[1024];
 	char person_mail[1024];
+	struct ident_split s;
+	const char *name_start, *name_end, *mail_start, *mail_end;
 
-	/* advance 'end' to point to email start delimiter */
-	for (end = 0; end < len && msg[end] != '<'; end++)
-		; /* do nothing */
-
-	/*
-	 * When end points at the '<' that we found, it should have
-	 * matching '>' later, which means 'end' must be strictly
-	 * below len - 1.
-	 */
-	if (end >= len - 2)
+	if (split_ident_line(&s, msg, len) < 0)
 		goto skip;
 
-	/* Seek for both name and email part */
-	name_start = msg;
-	name_end = msg+end;
-	while (name_end > name_start && isspace(*(name_end-1)))
-		name_end--;
-	mail_start = msg+end+1;
-	mail_end = mail_start;
-	while (mail_end < msg_end && *mail_end != '>')
-		mail_end++;
-	if (mail_end == msg_end)
-		goto skip;
-	end = mail_end-msg;
+	name_start = s.name_begin;
+	name_end = s.name_end;
+	mail_start = s.mail_begin;
+	mail_end = s.mail_end;
 
 	if (part == 'N' || part == 'E') { /* mailmap lookup */
-		strlcpy(person_name, name_start, name_end-name_start+1);
-		strlcpy(person_mail, mail_start, mail_end-mail_start+1);
+		strlcpy(person_name, name_start, name_end - name_start + 1);
+		strlcpy(person_mail, mail_start, mail_end - mail_start + 1);
 		mailmap_name(person_mail, sizeof(person_mail), person_name, sizeof(person_name));
 		name_start = person_name;
 		name_end = name_start + strlen(person_name);
@@ -581,28 +564,20 @@ static size_t format_person_part(struct strbuf *sb, char part,
 		return placeholder_len;
 	}
 
-	/* advance 'start' to point to date start delimiter */
-	for (start = end + 1; start < len && isspace(msg[start]); start++)
-		; /* do nothing */
-	if (start >= len)
-		goto skip;
-	date = strtoul(msg + start, &ep, 10);
-	if (msg + start == ep)
+	if (!s.date_begin)
 		goto skip;
 
+	date = strtoul(s.date_begin, NULL, 10);
+
 	if (part == 't') {	/* date, UNIX timestamp */
-		strbuf_add(sb, msg + start, ep - (msg + start));
+		strbuf_add(sb, s.date_begin, s.date_end - s.date_begin);
 		return placeholder_len;
 	}
 
 	/* parse tz */
-	for (start = ep - msg + 1; start < len && isspace(msg[start]); start++)
-		; /* do nothing */
-	if (start + 1 < len) {
-		tz = strtoul(msg + start + 1, NULL, 10);
-		if (msg[start] == '-')
-			tz = -tz;
-	}
+	tz = strtoul(s.tz_begin + 1, NULL, 10);
+	if (*s.tz_begin == '-')
+		tz = -tz;
 
 	switch (part) {
 	case 'd':	/* date */
@@ -621,8 +596,9 @@ static size_t format_person_part(struct strbuf *sb, char part,
 
 skip:
 	/*
-	 * bogus commit, 'sb' cannot be updated, but we still need to
-	 * compute a valid return value.
+	 * reading from either a bogus commit, or a reflog entry with
+	 * %gn, %ge, etc.; 'sb' cannot be updated, but we still need
+	 * to compute a valid return value.
 	 */
 	if (part == 'n' || part == 'e' || part == 't' || part == 'd'
 	    || part == 'D' || part == 'r' || part == 'i')
diff --git a/read-cache.c b/read-cache.c
index 274e54b4f3..6c8f395836 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -157,16 +157,6 @@ static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
 	return 0;
 }
 
-static int is_empty_blob_sha1(const unsigned char *sha1)
-{
-	static const unsigned char empty_blob_sha1[20] = {
-		0xe6,0x9d,0xe2,0x9b,0xb2,0xd1,0xd6,0x43,0x4b,0x8b,
-		0x29,0xae,0x77,0x5a,0xd8,0xc2,0xe4,0x8c,0x53,0x91
-	};
-
-	return !hashcmp(sha1, empty_blob_sha1);
-}
-
 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
 {
 	unsigned int changed = 0;
diff --git a/run-command.c b/run-command.c
index 1db8abf984..9c5a564ece 100644
--- a/run-command.c
+++ b/run-command.c
@@ -76,6 +76,68 @@ static inline void dup_devnull(int to)
 }
 #endif
 
+static char *locate_in_PATH(const char *file)
+{
+	const char *p = getenv("PATH");
+	struct strbuf buf = STRBUF_INIT;
+
+	if (!p || !*p)
+		return NULL;
+
+	while (1) {
+		const char *end = strchrnul(p, ':');
+
+		strbuf_reset(&buf);
+
+		/* POSIX specifies an empty entry as the current directory. */
+		if (end != p) {
+			strbuf_add(&buf, p, end - p);
+			strbuf_addch(&buf, '/');
+		}
+		strbuf_addstr(&buf, file);
+
+		if (!access(buf.buf, F_OK))
+			return strbuf_detach(&buf, NULL);
+
+		if (!*end)
+			break;
+		p = end + 1;
+	}
+
+	strbuf_release(&buf);
+	return NULL;
+}
+
+static int exists_in_PATH(const char *file)
+{
+	char *r = locate_in_PATH(file);
+	free(r);
+	return r != NULL;
+}
+
+int sane_execvp(const char *file, char * const argv[])
+{
+	if (!execvp(file, argv))
+		return 0; /* cannot happen ;-) */
+
+	/*
+	 * When a command can't be found because one of the directories
+	 * listed in $PATH is unsearchable, execvp reports EACCES, but
+	 * careful usability testing (read: analysis of occasional bug
+	 * reports) reveals that "No such file or directory" is more
+	 * intuitive.
+	 *
+	 * We avoid commands with "/", because execvp will not do $PATH
+	 * lookups in that case.
+	 *
+	 * The reassignment of EACCES to errno looks like a no-op below,
+	 * but we need to protect against exists_in_PATH overwriting errno.
+	 */
+	if (errno == EACCES && !strchr(file, '/'))
+		errno = exists_in_PATH(file) ? EACCES : ENOENT;
+	return -1;
+}
+
 static const char **prepare_shell_cmd(const char **argv)
 {
 	int argc, nargc = 0;
@@ -114,7 +176,7 @@ static int execv_shell_cmd(const char **argv)
 {
 	const char **nargv = prepare_shell_cmd(argv);
 	trace_argv_printf(nargv, "trace: exec:");
-	execvp(nargv[0], (char **)nargv);
+	sane_execvp(nargv[0], (char **)nargv);
 	free(nargv);
 	return -1;
 }
@@ -339,7 +401,7 @@ fail_pipe:
 		} else if (cmd->use_shell) {
 			execv_shell_cmd(cmd->argv);
 		} else {
-			execvp(cmd->argv[0], (char *const*) cmd->argv);
+			sane_execvp(cmd->argv[0], (char *const*) cmd->argv);
 		}
 		if (errno == ENOENT) {
 			if (!cmd->silent_exec_failure)
diff --git a/sequencer.c b/sequencer.c
index a37846a594..4307364b26 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -164,7 +164,7 @@ static void write_message(struct strbuf *msgbuf, const char *filename)
 
 static struct tree *empty_tree(void)
 {
-	return lookup_tree((const unsigned char *)EMPTY_TREE_SHA1_BIN);
+	return lookup_tree(EMPTY_TREE_SHA1_BIN);
 }
 
 static int error_dirty_index(struct replay_opts *opts)
diff --git a/submodule.h b/submodule.h
index 80e04f3c8c..9c5e5c0c30 100644
--- a/submodule.h
+++ b/submodule.h
@@ -13,7 +13,7 @@ enum {
 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 		const char *path);
 int submodule_config(const char *var, const char *value, void *cb);
-void gitmodules_config();
+void gitmodules_config(void);
 int parse_submodule_config_option(const char *var, const char *value);
 void handle_ignore_submodules_arg(struct diff_options *diffopt, const char *);
 int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg);
diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index 8d4938f019..17e969df60 100755
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh
@@ -34,4 +34,17 @@ test_expect_success POSIXPERM 'run_command reports EACCES' '
 	grep "fatal: cannot exec.*hello.sh" err
 '
 
+test_expect_success POSIXPERM 'unreadable directory in PATH' '
+	mkdir local-command &&
+	test_when_finished "chmod u+rwx local-command && rm -fr local-command" &&
+	git config alias.nitfol "!echo frotz" &&
+	chmod a-rx local-command &&
+	(
+		PATH=./local-command:$PATH &&
+		git nitfol >actual
+	) &&
+	echo frotz >expect &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t3310-notes-merge-manual-resolve.sh b/t/t3310-notes-merge-manual-resolve.sh
index 4367197953..195bb97f85 100755
--- a/t/t3310-notes-merge-manual-resolve.sh
+++ b/t/t3310-notes-merge-manual-resolve.sh
@@ -324,7 +324,7 @@ y and z notes on 4th commit
 EOF
 	git notes merge --commit &&
 	# No .git/NOTES_MERGE_* files left
-	test_must_fail ls .git/NOTES_MERGE_* >output 2>/dev/null &&
+	test_might_fail ls .git/NOTES_MERGE_* >output 2>/dev/null &&
 	test_cmp /dev/null output &&
 	# Merge commit has pre-merge y and pre-merge z as parents
 	test "$(git rev-parse refs/notes/m^1)" = "$(cat pre_merge_y)" &&
@@ -386,7 +386,7 @@ test_expect_success 'redo merge of z into m (== y) with default ("manual") resol
 test_expect_success 'abort notes merge' '
 	git notes merge --abort &&
 	# No .git/NOTES_MERGE_* files left
-	test_must_fail ls .git/NOTES_MERGE_* >output 2>/dev/null &&
+	test_might_fail ls .git/NOTES_MERGE_* >output 2>/dev/null &&
 	test_cmp /dev/null output &&
 	# m has not moved (still == y)
 	test "$(git rev-parse refs/notes/m)" = "$(cat pre_merge_y)" &&
@@ -453,7 +453,7 @@ EOF
 	# Finalize merge
 	git notes merge --commit &&
 	# No .git/NOTES_MERGE_* files left
-	test_must_fail ls .git/NOTES_MERGE_* >output 2>/dev/null &&
+	test_might_fail ls .git/NOTES_MERGE_* >output 2>/dev/null &&
 	test_cmp /dev/null output &&
 	# Merge commit has pre-merge y and pre-merge z as parents
 	test "$(git rev-parse refs/notes/m^1)" = "$(cat pre_merge_y)" &&
@@ -542,7 +542,7 @@ EOF
 test_expect_success 'resolve situation by aborting the notes merge' '
 	git notes merge --abort &&
 	# No .git/NOTES_MERGE_* files left
-	test_must_fail ls .git/NOTES_MERGE_* >output 2>/dev/null &&
+	test_might_fail ls .git/NOTES_MERGE_* >output 2>/dev/null &&
 	test_cmp /dev/null output &&
 	# m has not moved (still == w)
 	test "$(git rev-parse refs/notes/m)" = "$(git rev-parse refs/notes/w)" &&
@@ -553,4 +553,23 @@ test_expect_success 'resolve situation by aborting the notes merge' '
 	verify_notes z
 '
 
+cat >expect_notes <<EOF
+foo
+bar
+EOF
+
+test_expect_success 'switch cwd before committing notes merge' '
+	git notes add -m foo HEAD &&
+	git notes --ref=other add -m bar HEAD &&
+	test_must_fail git notes merge refs/notes/other &&
+	(
+		cd .git/NOTES_MERGE_WORKTREE &&
+		echo "foo" > $(git rev-parse HEAD) &&
+		echo "bar" >> $(git rev-parse HEAD) &&
+		git notes merge --commit
+	) &&
+	git notes show HEAD > actual_notes &&
+	test_cmp expect_notes actual_notes
+'
+
 test_done
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index 9e236f9cc0..098a6ae4a0 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -330,4 +330,30 @@ test_expect_success PERL 'split hunk "add -p (edit)"' '
 	! grep "^+15" actual
 '
 
+test_expect_success 'patch mode ignores unmerged entries' '
+	git reset --hard &&
+	test_commit conflict &&
+	test_commit non-conflict &&
+	git checkout -b side &&
+	test_commit side conflict.t &&
+	git checkout master &&
+	test_commit master conflict.t &&
+	test_must_fail git merge side &&
+	echo changed >non-conflict.t &&
+	echo y | git add -p >output &&
+	! grep a/conflict.t output &&
+	cat >expected <<-\EOF &&
+	* Unmerged path conflict.t
+	diff --git a/non-conflict.t b/non-conflict.t
+	index f766221..5ea2ed4 100644
+	--- a/non-conflict.t
+	+++ b/non-conflict.t
+	@@ -1 +1 @@
+	-non-conflict
+	+changed
+	EOF
+	git diff --cached >diff &&
+	test_cmp expected diff
+'
+
 test_done
diff --git a/t/t4034-diff-words.sh b/t/t4034-diff-words.sh
index 5c2012111c..30d42cb3bf 100755
--- a/t/t4034-diff-words.sh
+++ b/t/t4034-diff-words.sh
@@ -3,6 +3,7 @@
 test_description='word diff colors'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/diff-lib.sh
 
 cat >pre.simple <<-\EOF
 	h(4)
@@ -293,6 +294,10 @@ test_expect_success '--word-diff=none' '
 	word_diff --word-diff=plain --word-diff=none
 '
 
+test_expect_success 'unset default driver' '
+	test_unconfig diff.wordregex
+'
+
 test_language_driver bibtex
 test_language_driver cpp
 test_language_driver csharp
@@ -348,4 +353,35 @@ test_expect_success 'word-diff with no newline at EOF' '
 	word_diff --word-diff=plain
 '
 
+test_expect_success 'setup history with two files' '
+	echo "a b; c" >a.tex &&
+	echo "a b; c" >z.txt &&
+	git add a.tex z.txt &&
+	git commit -minitial &&
+
+	# modify both
+	echo "a bx; c" >a.tex &&
+	echo "a bx; c" >z.txt &&
+	git commit -mmodified -a
+'
+
+test_expect_success 'wordRegex for the first file does not apply to the second' '
+	echo "*.tex diff=tex" >.gitattributes &&
+	git config diff.tex.wordRegex "[a-z]+|." &&
+	cat >expect <<-\EOF &&
+		diff --git a/a.tex b/a.tex
+		--- a/a.tex
+		+++ b/a.tex
+		@@ -1 +1 @@
+		a [-b-]{+bx+}; c
+		diff --git a/z.txt b/z.txt
+		--- a/z.txt
+		+++ b/z.txt
+		@@ -1 +1 @@
+		a [-b;-]{+bx;+} c
+	EOF
+	git diff --word-diff HEAD~ >actual &&
+	compare_diff_patch expect actual
+'
+
 test_done
diff --git a/t/t5528-push-default.sh b/t/t5528-push-default.sh
new file mode 100755
index 0000000000..c334c51a07
--- /dev/null
+++ b/t/t5528-push-default.sh
@@ -0,0 +1,54 @@
+#!/bin/sh
+
+test_description='check various push.default settings'
+. ./test-lib.sh
+
+test_expect_success 'setup bare remotes' '
+	git init --bare repo1 &&
+	git remote add parent1 repo1 &&
+	git init --bare repo2 &&
+	git remote add parent2 repo2 &&
+	test_commit one &&
+	git push parent1 HEAD &&
+	git push parent2 HEAD
+'
+
+test_expect_success '"upstream" pushes to configured upstream' '
+	git checkout master &&
+	test_config branch.master.remote parent1 &&
+	test_config branch.master.merge refs/heads/foo &&
+	test_config push.default upstream &&
+	test_commit two &&
+	git push &&
+	echo two >expect &&
+	git --git-dir=repo1 log -1 --format=%s foo >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '"upstream" does not push on unconfigured remote' '
+	git checkout master &&
+	test_unconfig branch.master.remote &&
+	test_config push.default upstream &&
+	test_commit three &&
+	test_must_fail git push
+'
+
+test_expect_success '"upstream" does not push on unconfigured branch' '
+	git checkout master &&
+	test_config branch.master.remote parent1 &&
+	test_unconfig branch.master.merge &&
+	test_config push.default upstream
+	test_commit four &&
+	test_must_fail git push
+'
+
+test_expect_success '"upstream" does not push when remotes do not match' '
+	git checkout master &&
+	test_config branch.master.remote parent1 &&
+	test_config branch.master.merge refs/heads/foo &&
+	test_config push.default upstream &&
+	test_commit five &&
+	test_must_fail git push parent2
+'
+
+test_done
diff --git a/t/t6022-merge-rename.sh b/t/t6022-merge-rename.sh
index 9d8584e957..1104249182 100755
--- a/t/t6022-merge-rename.sh
+++ b/t/t6022-merge-rename.sh
@@ -884,4 +884,20 @@ test_expect_success 'no spurious "refusing to lose untracked" message' '
 	! grep "refusing to lose untracked file" errors.txt
 '
 
+test_expect_success 'do not follow renames for empty files' '
+	git checkout -f -b empty-base &&
+	>empty1 &&
+	git add empty1 &&
+	git commit -m base &&
+	echo content >empty1 &&
+	git add empty1 &&
+	git commit -m fill &&
+	git checkout -b empty-topic HEAD^ &&
+	git mv empty1 empty2 &&
+	git commit -m rename &&
+	test_must_fail git merge empty-base &&
+	>expect &&
+	test_cmp expect empty2
+'
+
 test_done
diff --git a/t/t7300-clean.sh b/t/t7300-clean.sh
index 800b5368a5..ccfb54de7a 100755
--- a/t/t7300-clean.sh
+++ b/t/t7300-clean.sh
@@ -399,8 +399,8 @@ test_expect_success SANITY 'removal failure' '
 '
 
 test_expect_success 'nested git work tree' '
-	rm -fr foo bar &&
-	mkdir foo bar &&
+	rm -fr foo bar baz &&
+	mkdir -p foo bar baz/boo &&
 	(
 		cd foo &&
 		git init &&
@@ -412,15 +412,24 @@ test_expect_success 'nested git work tree' '
 		cd bar &&
 		>goodbye.people
 	) &&
+	(
+		cd baz/boo &&
+		git init &&
+		>deeper.world
+		git add . &&
+		git commit -a -m deeply.nested
+	) &&
 	git clean -f -d &&
 	test -f foo/.git/index &&
 	test -f foo/hello.world &&
+	test -f baz/boo/.git/index &&
+	test -f baz/boo/deeper.world &&
 	! test -d bar
 '
 
 test_expect_success 'force removal of nested git work tree' '
-	rm -fr foo bar &&
-	mkdir foo bar &&
+	rm -fr foo bar baz &&
+	mkdir -p foo bar baz/boo &&
 	(
 		cd foo &&
 		git init &&
@@ -432,9 +441,17 @@ test_expect_success 'force removal of nested git work tree' '
 		cd bar &&
 		>goodbye.people
 	) &&
+	(
+		cd baz/boo &&
+		git init &&
+		>deeper.world
+		git add . &&
+		git commit -a -m deeply.nested
+	) &&
 	git clean -f -f -d &&
 	! test -d foo &&
-	! test -d bar
+	! test -d bar &&
+	! test -d baz
 '
 
 test_expect_success 'git clean -e' '
diff --git a/t/t7501-commit.sh b/t/t7501-commit.sh
index 8bb38337a9..b20ca0eace 100755
--- a/t/t7501-commit.sh
+++ b/t/t7501-commit.sh
@@ -30,10 +30,12 @@ test_expect_success 'setup: initial commit' '
 '
 
 test_expect_success '-m and -F do not mix' '
+	git checkout HEAD file && echo >>file && git add file &&
 	test_must_fail git commit -m foo -m bar -F file
 '
 
 test_expect_success '-m and -C do not mix' '
+	git checkout HEAD file && echo >>file && git add file &&
 	test_must_fail git commit -C HEAD -m illegal
 '
 
@@ -79,7 +81,19 @@ test_expect_success 'empty commit message' '
 	test_must_fail git commit -F msg -a
 '
 
+test_expect_success 'template "emptyness" check does not kick in with -F' '
+	git checkout HEAD file && echo >>file && git add file &&
+	git commit -t file -F file
+'
+
+test_expect_success 'template "emptyness" check' '
+	git checkout HEAD file && echo >>file && git add file &&
+	test_must_fail git commit -t file 2>err &&
+	test_i18ngrep "did not edit" err
+'
+
 test_expect_success 'setup: commit message from file' '
+	git checkout HEAD file && echo >>file && git add file &&
 	echo this is the commit message, coming from a file >msg &&
 	git commit -F msg -a
 '
diff --git a/t/t7503-pre-commit-hook.sh b/t/t7503-pre-commit-hook.sh
index ee7f0cd459..984889b39d 100755
--- a/t/t7503-pre-commit-hook.sh
+++ b/t/t7503-pre-commit-hook.sh
@@ -118,4 +118,22 @@ test_expect_success 'with failing hook requiring GIT_PREFIX' '
 	git checkout -- file
 '
 
+test_expect_success 'check the author in hook' '
+	write_script "$HOOK" <<-\EOF &&
+	test "$GIT_AUTHOR_NAME" = "New Author" &&
+	test "$GIT_AUTHOR_EMAIL" = "newauthor@example.com"
+	EOF
+	test_must_fail git commit --allow-empty -m "by a.u.thor" &&
+	(
+		GIT_AUTHOR_NAME="New Author" &&
+		GIT_AUTHOR_EMAIL="newauthor@example.com" &&
+		export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL &&
+		git commit --allow-empty -m "by new.author via env" &&
+		git show -s
+	) &&
+	git commit --author="New Author <newauthor@example.com>" \
+		--allow-empty -m "by new.author via command line" &&
+	git show -s
+'
+
 test_done
diff --git a/test-subprocess.c b/test-subprocess.c
index 8926bc52a9..f2d4c0d22b 100644
--- a/test-subprocess.c
+++ b/test-subprocess.c
@@ -1,7 +1,7 @@
 #include "cache.h"
 #include "run-command.h"
 
-int main(int argc, char **argv)
+int main(int argc, const char **argv)
 {
 	struct child_process cp;
 	int nogit = 0;
@@ -9,12 +9,12 @@ int main(int argc, char **argv)
 	setup_git_directory_gently(&nogit);
 	if (nogit)
 		die("No git repo found");
-	if (!strcmp(argv[1], "--setup-work-tree")) {
+	if (argc > 1 && !strcmp(argv[1], "--setup-work-tree")) {
 		setup_work_tree();
 		argv++;
 	}
 	memset(&cp, 0, sizeof(cp));
 	cp.git_cmd = 1;
-	cp.argv = (const char **)argv+1;
+	cp.argv = argv + 1;
 	return run_command(&cp);
 }