Merge branch 'jk/trailer-fixes'

"git interpret-trailers" and its underlying machinery had a buggy
code that attempted to ignore patch text after commit log message,
which triggered in various codepaths that will always get the log
message alone and never get such an input.

* jk/trailer-fixes:
  append_signoff: use size_t for string offsets
  sequencer: ignore "---" divider when parsing trailers
  pretty, ref-filter: format %(trailers) with no_divider option
  interpret-trailers: allow suppressing "---" divider
  interpret-trailers: tighten check for "---" patch boundary
  trailer: pass process_trailer_opts to trailer_info_get()
  trailer: use size_t for iterating trailer list
  trailer: use size_t for string offsets

14 files changed, 175 insertions, 39 deletions

diff --git a/Documentation/git-interpret-trailers.txt b/Documentation/git-interpret-trailers.txt
index b8fafb1e8b..a5e8b36f62 100644
--- a/Documentation/git-interpret-trailers.txt
+++ b/Documentation/git-interpret-trailers.txt
@@ -56,8 +56,9 @@ least one Git-generated or user-configured trailer and consists of at
 least 25% trailers.
 The group must be preceded by one or more empty (or whitespace-only) lines.
 The group must either be at the end of the message or be the last
-non-whitespace lines before a line that starts with '---'. Such three
-minus signs start the patch part of the message.
+non-whitespace lines before a line that starts with '---' (followed by a
+space or the end of the line). Such three minus signs start the patch
+part of the message. See also `--no-divider` below.
 
 When reading trailers, there can be whitespaces after the
 token, the separator and the value. There can also be whitespaces
@@ -125,6 +126,11 @@ OPTIONS
 	A convenience alias for `--only-trailers --only-input
 	--unfold`.
 
+--no-divider::
+	Do not treat `---` as the end of the commit message. Use this
+	when you know your input contains just the commit message itself
+	(and not an email or the output of `git format-patch`).
+
 CONFIGURATION VARIABLES
 -----------------------
 
diff --git a/builtin/interpret-trailers.c b/builtin/interpret-trailers.c
index b742539d4d..4b87e0dd2e 100644
--- a/builtin/interpret-trailers.c
+++ b/builtin/interpret-trailers.c
@@ -104,6 +104,7 @@ int cmd_interpret_trailers(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "unfold", &opts.unfold, N_("join whitespace-continued values")),
 		{ OPTION_CALLBACK, 0, "parse", &opts, NULL, N_("set parsing options"),
 			PARSE_OPT_NOARG | PARSE_OPT_NONEG, parse_opt_parse },
+		OPT_BOOL(0, "no-divider", &opts.no_divider, N_("do not treat --- specially")),
 		OPT_CALLBACK(0, "trailer", &trailers, N_("trailer"),
 				N_("trailer(s) to add"), option_parse_trailer),
 		OPT_END()
diff --git a/commit.c b/commit.c
index 5781f9bc67..d6f7f5e4d2 100644
--- a/commit.c
+++ b/commit.c
@@ -1426,10 +1426,10 @@ const char *find_commit_header(const char *msg, const char *key, size_t *out_len
  * Returns the number of bytes from the tail to ignore, to be fed as
  * the second parameter to append_signoff().
  */
-int ignore_non_trailer(const char *buf, size_t len)
+size_t ignore_non_trailer(const char *buf, size_t len)
 {
-	int boc = 0;
-	int bol = 0;
+	size_t boc = 0;
+	size_t bol = 0;
 	int in_old_conflicts_block = 0;
 	size_t cutoff = wt_status_locate_end(buf, len);
 
diff --git a/commit.h b/commit.h
index e2c99d9b04..2b1a734388 100644
--- a/commit.h
+++ b/commit.h
@@ -293,7 +293,7 @@ extern const char *find_commit_header(const char *msg, const char *key,
 				      size_t *out_len);
 
 /* Find the end of the log message, the right place for a new trailer. */
-extern int ignore_non_trailer(const char *buf, size_t len);
+extern size_t ignore_non_trailer(const char *buf, size_t len);
 
 typedef int (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
 				 void *cb_data);
diff --git a/pretty.c b/pretty.c
index 98cf5228f9..8ca29e9281 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1304,6 +1304,9 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 
 	if (skip_prefix(placeholder, "(trailers", &arg)) {
 		struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
+
+		opts.no_divider = 1;
+
 		if (*arg == ':') {
 			arg++;
 			for (;;) {
diff --git a/ref-filter.c b/ref-filter.c
index 9bacd32f0a..e1bcb4ca8a 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -264,6 +264,8 @@ static int trailers_atom_parser(const struct ref_format *format, struct used_ato
 	struct string_list params = STRING_LIST_INIT_DUP;
 	int i;
 
+	atom->u.contents.trailer_opts.no_divider = 1;
+
 	if (arg) {
 		string_list_split(&params, arg, ',', -1);
 		for (i = 0; i < params.nr; i++) {
diff --git a/sequencer.c b/sequencer.c
index bd159991e9..9ba873b875 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -226,13 +226,16 @@ static const char *get_todo_path(const struct replay_opts *opts)
  * Returns 3 when sob exists within conforming footer as last entry
  */
 static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
-	int ignore_footer)
+	size_t ignore_footer)
 {
+	struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
 	struct trailer_info info;
-	int i;
+	size_t i;
 	int found_sob = 0, found_sob_last = 0;
 
-	trailer_info_get(&info, sb->buf);
+	opts.no_divider = 1;
+
+	trailer_info_get(&info, sb->buf, &opts);
 
 	if (info.trailer_start == info.trailer_end)
 		return 0;
@@ -3829,7 +3832,7 @@ int sequencer_pick_revisions(struct replay_opts *opts)
 	return res;
 }
 
-void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
+void append_signoff(struct strbuf *msgbuf, size_t ignore_footer, unsigned flag)
 {
 	unsigned no_dup_sob = flag & APPEND_SIGNOFF_DEDUP;
 	struct strbuf sob = STRBUF_INIT;
diff --git a/sequencer.h b/sequencer.h
index c751c9d6e4..c986bc8251 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -90,7 +90,14 @@ int rearrange_squash(void);
 
 extern const char sign_off_header[];
 
-void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag);
+/*
+ * Append a signoff to the commit message in "msgbuf". The ignore_footer
+ * parameter specifies the number of bytes at the end of msgbuf that should
+ * not be considered at all. I.e., they are not checked for existing trailers,
+ * and the new signoff will be spliced into the buffer before those bytes.
+ */
+void append_signoff(struct strbuf *msgbuf, size_t ignore_footer, unsigned flag);
+
 void append_conflicts_hint(struct strbuf *msgbuf);
 int message_is_empty(const struct strbuf *sb,
 		     enum commit_msg_cleanup_mode cleanup_mode);
diff --git a/t/t4205-log-pretty-formats.sh b/t/t4205-log-pretty-formats.sh
index 2052cadb11..978a8a66ff 100755
--- a/t/t4205-log-pretty-formats.sh
+++ b/t/t4205-log-pretty-formats.sh
@@ -598,4 +598,27 @@ test_expect_success ':only and :unfold work together' '
 	test_cmp expect actual
 '
 
+test_expect_success 'trailer parsing not fooled by --- line' '
+	git commit --allow-empty -F - <<-\EOF &&
+	this is the subject
+
+	This is the body. The message has a "---" line which would confuse a
+	message+patch parser. But here we know we have only a commit message,
+	so we get it right.
+
+	trailer: wrong
+	---
+	This is more body.
+
+	trailer: right
+	EOF
+
+	{
+		echo "trailer: right" &&
+		echo
+	} >expect &&
+	git log --no-walk --format="%(trailers)" >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index 024f8c06f7..97bfbee6e8 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -715,6 +715,29 @@ test_expect_success 'basic atom: head contents:trailers' '
 	test_cmp expect actual.clean
 '
 
+test_expect_success 'trailer parsing not fooled by --- line' '
+	git commit --allow-empty -F - <<-\EOF &&
+	this is the subject
+
+	This is the body. The message has a "---" line which would confuse a
+	message+patch parser. But here we know we have only a commit message,
+	so we get it right.
+
+	trailer: wrong
+	---
+	This is more body.
+
+	trailer: right
+	EOF
+
+	{
+		echo "trailer: right" &&
+		echo
+	} >expect &&
+	git for-each-ref --format="%(trailers)" refs/heads/master >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'Add symbolic ref for the following tests' '
 	git symbolic-ref refs/heads/sym refs/heads/master
 '
diff --git a/t/t7501-commit.sh b/t/t7501-commit.sh
index 4cae92804d..1a6773ee68 100755
--- a/t/t7501-commit.sh
+++ b/t/t7501-commit.sh
@@ -517,6 +517,22 @@ Myfooter: x" &&
 	test_cmp expected actual
 '
 
+test_expect_success 'signoff not confused by ---' '
+	cat >expected <<-EOF &&
+		subject
+
+		body
+		---
+		these dashes confuse the parser!
+
+		Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>
+	EOF
+	# should be a noop, since we already signed
+	git commit --allow-empty --signoff -F expected &&
+	git log -1 --pretty=format:%B >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'multiple -m' '
 
 	>negative &&
diff --git a/t/t7513-interpret-trailers.sh b/t/t7513-interpret-trailers.sh
index 164719d1c9..c441861331 100755
--- a/t/t7513-interpret-trailers.sh
+++ b/t/t7513-interpret-trailers.sh
@@ -1417,4 +1417,46 @@ test_expect_success 'unfold' '
 	test_cmp expected actual
 '
 
+test_expect_success 'handling of --- lines in input' '
+	echo "real-trailer: just right" >expected &&
+
+	git interpret-trailers --parse >actual <<-\EOF &&
+	subject
+
+	body
+
+	not-a-trailer: too soon
+	------ this is just a line in the commit message with a bunch of
+	------ dashes; it does not have any syntactic meaning.
+
+	real-trailer: just right
+	---
+	below the dashed line may be a patch, etc.
+
+	not-a-trailer: too late
+	EOF
+
+	test_cmp expected actual
+'
+
+test_expect_success 'suppress --- handling' '
+	echo "real-trailer: just right" >expected &&
+
+	git interpret-trailers --parse --no-divider >actual <<-\EOF &&
+	subject
+
+	This commit message has a "---" in it, but because we tell
+	interpret-trailers not to respect that, it has no effect.
+
+	not-a-trailer: too soon
+	---
+
+	This is still the commit message body.
+
+	real-trailer: just right
+	EOF
+
+	test_cmp expected actual
+'
+
 test_done
diff --git a/trailer.c b/trailer.c
index 4e309460d1..0796f326b3 100644
--- a/trailer.c
+++ b/trailer.c
@@ -585,7 +585,7 @@ static const char *token_from_item(struct arg_item *item, char *tok)
 	return item->conf.name;
 }
 
-static int token_matches_item(const char *tok, struct arg_item *item, int tok_len)
+static int token_matches_item(const char *tok, struct arg_item *item, size_t tok_len)
 {
 	if (!strncasecmp(tok, item->conf.name, tok_len))
 		return 1;
@@ -603,7 +603,7 @@ static int token_matches_item(const char *tok, struct arg_item *item, int tok_le
  * distinguished from the non-well-formed-line case (in which this function
  * returns -1) because some callers of this function need such a distinction.
  */
-static int find_separator(const char *line, const char *separators)
+static ssize_t find_separator(const char *line, const char *separators)
 {
 	int whitespace_found = 0;
 	const char *c;
@@ -630,10 +630,10 @@ static int find_separator(const char *line, const char *separators)
  */
 static void parse_trailer(struct strbuf *tok, struct strbuf *val,
 			 const struct conf_info **conf, const char *trailer,
-			 int separator_pos)
+			 ssize_t separator_pos)
 {
 	struct arg_item *item;
-	int tok_len;
+	size_t tok_len;
 	struct list_head *pos;
 
 	if (separator_pos != -1) {
@@ -721,7 +721,7 @@ static void process_command_line_args(struct list_head *arg_head,
 	list_for_each(pos, new_trailer_head) {
 		struct new_trailer_item *tr =
 			list_entry(pos, struct new_trailer_item, list);
-		int separator_pos = find_separator(tr->text, cl_separators);
+		ssize_t separator_pos = find_separator(tr->text, cl_separators);
 
 		if (separator_pos == 0) {
 			struct strbuf sb = STRBUF_INIT;
@@ -763,9 +763,9 @@ static const char *next_line(const char *str)
 /*
  * Return the position of the start of the last line. If len is 0, return -1.
  */
-static int last_line(const char *buf, size_t len)
+static ssize_t last_line(const char *buf, size_t len)
 {
-	int i;
+	ssize_t i;
 	if (len == 0)
 		return -1;
 	if (len == 1)
@@ -788,12 +788,14 @@ static int last_line(const char *buf, size_t len)
  * Return the position of the start of the patch or the length of str if there
  * is no patch in the message.
  */
-static int find_patch_start(const char *str)
+static size_t find_patch_start(const char *str)
 {
 	const char *s;
 
 	for (s = str; *s; s = next_line(s)) {
-		if (starts_with(s, "---"))
+		const char *v;
+
+		if (skip_prefix(s, "---", &v) && isspace(*v))
 			return s - str;
 	}
 
@@ -804,10 +806,11 @@ static int find_patch_start(const char *str)
  * Return the position of the first trailer line or len if there are no
  * trailers.
  */
-static int find_trailer_start(const char *buf, size_t len)
+static size_t find_trailer_start(const char *buf, size_t len)
 {
 	const char *s;
-	int end_of_title, l, only_spaces = 1;
+	ssize_t end_of_title, l;
+	int only_spaces = 1;
 	int recognized_prefix = 0, trailer_lines = 0, non_trailer_lines = 0;
 	/*
 	 * Number of possible continuation lines encountered. This will be
@@ -838,7 +841,7 @@ static int find_trailer_start(const char *buf, size_t len)
 	     l = last_line(buf, l)) {
 		const char *bol = buf + l;
 		const char **p;
-		int separator_pos;
+		ssize_t separator_pos;
 
 		if (bol[0] == comment_line_char) {
 			non_trailer_lines += possible_continuation_lines;
@@ -899,14 +902,14 @@ continue_outer_loop:
 }
 
 /* Return the position of the end of the trailers. */
-static int find_trailer_end(const char *buf, size_t len)
+static size_t find_trailer_end(const char *buf, size_t len)
 {
 	return len - ignore_non_trailer(buf, len);
 }
 
 static int ends_with_blank_line(const char *buf, size_t len)
 {
-	int ll = last_line(buf, len);
+	ssize_t ll = last_line(buf, len);
 	if (ll < 0)
 		return 0;
 	return is_blank_line(buf + ll);
@@ -939,17 +942,17 @@ static void unfold_value(struct strbuf *val)
 	strbuf_release(&out);
 }
 
-static int process_input_file(FILE *outfile,
-			      const char *str,
-			      struct list_head *head,
-			      const struct process_trailer_options *opts)
+static size_t process_input_file(FILE *outfile,
+				 const char *str,
+				 struct list_head *head,
+				 const struct process_trailer_options *opts)
 {
 	struct trailer_info info;
 	struct strbuf tok = STRBUF_INIT;
 	struct strbuf val = STRBUF_INIT;
-	int i;
+	size_t i;
 
-	trailer_info_get(&info, str);
+	trailer_info_get(&info, str, opts);
 
 	/* Print lines before the trailers as is */
 	if (!opts->only_trailers)
@@ -1032,7 +1035,7 @@ void process_trailers(const char *file,
 {
 	LIST_HEAD(head);
 	struct strbuf sb = STRBUF_INIT;
-	int trailer_end;
+	size_t trailer_end;
 	FILE *outfile = stdout;
 
 	ensure_configured();
@@ -1066,7 +1069,8 @@ void process_trailers(const char *file,
 	strbuf_release(&sb);
 }
 
-void trailer_info_get(struct trailer_info *info, const char *str)
+void trailer_info_get(struct trailer_info *info, const char *str,
+		      const struct process_trailer_options *opts)
 {
 	int patch_start, trailer_end, trailer_start;
 	struct strbuf **trailer_lines, **ptr;
@@ -1076,7 +1080,11 @@ void trailer_info_get(struct trailer_info *info, const char *str)
 
 	ensure_configured();
 
-	patch_start = find_patch_start(str);
+	if (opts->no_divider)
+		patch_start = strlen(str);
+	else
+		patch_start = find_patch_start(str);
+
 	trailer_end = find_trailer_end(str, patch_start);
 	trailer_start = find_trailer_start(str, trailer_end);
 
@@ -1111,7 +1119,7 @@ void trailer_info_get(struct trailer_info *info, const char *str)
 
 void trailer_info_release(struct trailer_info *info)
 {
-	int i;
+	size_t i;
 	for (i = 0; i < info->trailer_nr; i++)
 		free(info->trailers[i]);
 	free(info->trailers);
@@ -1121,7 +1129,7 @@ static void format_trailer_info(struct strbuf *out,
 				const struct trailer_info *info,
 				const struct process_trailer_options *opts)
 {
-	int i;
+	size_t i;
 
 	/* If we want the whole block untouched, we can take the fast path. */
 	if (!opts->only_trailers && !opts->unfold) {
@@ -1132,7 +1140,7 @@ static void format_trailer_info(struct strbuf *out,
 
 	for (i = 0; i < info->trailer_nr; i++) {
 		char *trailer = info->trailers[i];
-		int separator_pos = find_separator(trailer, separators);
+		ssize_t separator_pos = find_separator(trailer, separators);
 
 		if (separator_pos >= 1) {
 			struct strbuf tok = STRBUF_INIT;
@@ -1158,7 +1166,7 @@ void format_trailers_from_commit(struct strbuf *out, const char *msg,
 {
 	struct trailer_info info;
 
-	trailer_info_get(&info, msg);
+	trailer_info_get(&info, msg, opts);
 	format_trailer_info(out, &info, opts);
 	trailer_info_release(&info);
 }
diff --git a/trailer.h b/trailer.h
index 9c10026c35..b997739649 100644
--- a/trailer.h
+++ b/trailer.h
@@ -71,6 +71,7 @@ struct process_trailer_options {
 	int only_trailers;
 	int only_input;
 	int unfold;
+	int no_divider;
 };
 
 #define PROCESS_TRAILER_OPTIONS_INIT {0}
@@ -79,7 +80,8 @@ void process_trailers(const char *file,
 		      const struct process_trailer_options *opts,
 		      struct list_head *new_trailer_head);
 
-void trailer_info_get(struct trailer_info *info, const char *str);
+void trailer_info_get(struct trailer_info *info, const char *str,
+		      const struct process_trailer_options *opts);
 
 void trailer_info_release(struct trailer_info *info);