Merge branch 'hv/trailer-formatting'

The logic to handle "trailer" related placeholders in the
"--format=" mechanisms in the "log" family and "for-each-ref"
family is getting unified.

* hv/trailer-formatting:
  ref-filter: use pretty.c logic for trailers
  pretty.c: capture invalid trailer argument
  pretty.c: refactor trailer logic to `format_set_trailers_options()`
  t6300: use function to test trailer options

Author: gitster

Documentation/git-for-each-ref.txt

@@ -260,11 +260,9 @@ contents:lines=N::
 	The first `N` lines of the message.
 
 Additionally, the trailers as interpreted by linkgit:git-interpret-trailers[1]
-are obtained as `trailers` (or by using the historical alias
-`contents:trailers`).  Non-trailer lines from the trailer block can be omitted
-with `trailers:only`. Whitespace-continuations can be removed from trailers so
-that each trailer appears on a line by itself with its full content with
-`trailers:unfold`. Both can be used together as `trailers:unfold,only`.
+are obtained as `trailers[:options]` (or by using the historical alias
+`contents:trailers[:options]`). For valid [:option] values see `trailers`
+section of linkgit:git-log[1].
 
 For sorting purposes, fields with numeric values sort in numeric order
 (`objectsize`, `authordate`, `committerdate`, `creatordate`, `taggerdate`).

pretty.c

@@ -1149,6 +1149,63 @@ static int format_trailer_match_cb(const struct strbuf *key, void *ud)
 	return 0;
 }
 
+int format_set_trailers_options(struct process_trailer_options *opts,
+				struct string_list *filter_list,
+				struct strbuf *sepbuf,
+				struct strbuf *kvsepbuf,
+				const char **arg,
+				char **invalid_arg)
+{
+	for (;;) {
+		const char *argval;
+		size_t arglen;
+
+		if (**arg == ')')
+			break;
+
+		if (match_placeholder_arg_value(*arg, "key", arg, &argval, &arglen)) {
+			uintptr_t len = arglen;
+
+			if (!argval)
+				return -1;
+
+			if (len && argval[len - 1] == ':')
+				len--;
+			string_list_append(filter_list, argval)->util = (char *)len;
+
+			opts->filter = format_trailer_match_cb;
+			opts->filter_data = filter_list;
+			opts->only_trailers = 1;
+		} else if (match_placeholder_arg_value(*arg, "separator", arg, &argval, &arglen)) {
+			char *fmt;
+
+			strbuf_reset(sepbuf);
+			fmt = xstrndup(argval, arglen);
+			strbuf_expand(sepbuf, fmt, strbuf_expand_literal_cb, NULL);
+			free(fmt);
+			opts->separator = sepbuf;
+		} else if (match_placeholder_arg_value(*arg, "key_value_separator", arg, &argval, &arglen)) {
+			char *fmt;
+
+			strbuf_reset(kvsepbuf);
+			fmt = xstrndup(argval, arglen);
+			strbuf_expand(kvsepbuf, fmt, strbuf_expand_literal_cb, NULL);
+			free(fmt);
+			opts->key_value_separator = kvsepbuf;
+		} else if (!match_placeholder_bool_arg(*arg, "only", arg, &opts->only_trailers) &&
+			   !match_placeholder_bool_arg(*arg, "unfold", arg, &opts->unfold) &&
+			   !match_placeholder_bool_arg(*arg, "keyonly", arg, &opts->key_only) &&
+			   !match_placeholder_bool_arg(*arg, "valueonly", arg, &opts->value_only)) {
+			if (invalid_arg) {
+				size_t len = strcspn(*arg, ",)");
+				*invalid_arg = xstrndup(*arg, len);
+			}
+			return -1;
+		}
+	}
+	return 0;
+}
+
 static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 				const char *placeholder,
 				void *context)
@@ -1429,45 +1486,8 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 
 		if (*arg == ':') {
 			arg++;
-			for (;;) {
-				const char *argval;
-				size_t arglen;
-
-				if (match_placeholder_arg_value(arg, "key", &arg, &argval, &arglen)) {
-					uintptr_t len = arglen;
-
-					if (!argval)
-						goto trailer_out;
-
-					if (len && argval[len - 1] == ':')
-						len--;
-					string_list_append(&filter_list, argval)->util = (char *)len;
-
-					opts.filter = format_trailer_match_cb;
-					opts.filter_data = &filter_list;
-					opts.only_trailers = 1;
-				} else if (match_placeholder_arg_value(arg, "separator", &arg, &argval, &arglen)) {
-					char *fmt;
-
-					strbuf_reset(&sepbuf);
-					fmt = xstrndup(argval, arglen);
-					strbuf_expand(&sepbuf, fmt, strbuf_expand_literal_cb, NULL);
-					free(fmt);
-					opts.separator = &sepbuf;
-				} else if (match_placeholder_arg_value(arg, "key_value_separator", &arg, &argval, &arglen)) {
-					char *fmt;
-
-					strbuf_reset(&kvsepbuf);
-					fmt = xstrndup(argval, arglen);
-					strbuf_expand(&kvsepbuf, fmt, strbuf_expand_literal_cb, NULL);
-					free(fmt);
-					opts.key_value_separator = &kvsepbuf;
-				} else if (!match_placeholder_bool_arg(arg, "only", &arg, &opts.only_trailers) &&
-					   !match_placeholder_bool_arg(arg, "unfold", &arg, &opts.unfold) &&
-					   !match_placeholder_bool_arg(arg, "keyonly", &arg, &opts.key_only) &&
-					   !match_placeholder_bool_arg(arg, "valueonly", &arg, &opts.value_only))
-					break;
-			}
+			if (format_set_trailers_options(&opts, &filter_list, &sepbuf, &kvsepbuf, &arg, NULL))
+				goto trailer_out;
 		}
 		if (*arg == ')') {
 			format_trailers_from_commit(sb, msg + c->subject_off, &opts);

pretty.h

@@ -6,6 +6,7 @@
 
 struct commit;
 struct strbuf;
+struct process_trailer_options;
 
 /* Commit formats */
 enum cmit_fmt {
@@ -142,4 +143,15 @@ int commit_format_is_empty(enum cmit_fmt);
 /* Make subject of commit message suitable for filename */
 void format_sanitized_subject(struct strbuf *sb, const char *msg, size_t len);
 
+/*
+ * Set values of fields in "struct process_trailer_options"
+ * according to trailers arguments.
+ */
+int format_set_trailers_options(struct process_trailer_options *opts,
+			struct string_list *filter_list,
+			struct strbuf *sepbuf,
+			struct strbuf *kvsepbuf,
+			const char **arg,
+			char **invalid_arg);
+
 #endif /* PRETTY_H */

ref-filter.c

@@ -67,6 +67,12 @@ struct refname_atom {
 	int lstrip, rstrip;
 };
 
+static struct ref_trailer_buf {
+	struct string_list filter_list;
+	struct strbuf sepbuf;
+	struct strbuf kvsepbuf;
+} ref_trailer_buf = {STRING_LIST_INIT_NODUP, STRBUF_INIT, STRBUF_INIT};
+
 static struct expand_data {
 	struct object_id oid;
 	enum object_type type;
@@ -313,28 +319,26 @@ static int subject_atom_parser(const struct ref_format *format, struct used_atom
 static int trailers_atom_parser(const struct ref_format *format, struct used_atom *atom,
 				const char *arg, struct strbuf *err)
 {
-	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++) {
-			const char *s = params.items[i].string;
-			if (!strcmp(s, "unfold"))
-				atom->u.contents.trailer_opts.unfold = 1;
-			else if (!strcmp(s, "only"))
-				atom->u.contents.trailer_opts.only_trailers = 1;
-			else {
-				strbuf_addf(err, _("unknown %%(trailers) argument: %s"), s);
-				string_list_clear(&params, 0);
-				return -1;
-			}
+		const char *argbuf = xstrfmt("%s)", arg);
+		char *invalid_arg = NULL;
+
+		if (format_set_trailers_options(&atom->u.contents.trailer_opts,
+		    &ref_trailer_buf.filter_list,
+		    &ref_trailer_buf.sepbuf,
+		    &ref_trailer_buf.kvsepbuf,
+		    &argbuf, &invalid_arg)) {
+			if (!invalid_arg)
+				strbuf_addf(err, _("expected %%(trailers:key=<value>)"));
+			else
+				strbuf_addf(err, _("unknown %%(trailers) argument: %s"), invalid_arg);
+			free((char *)invalid_arg);
+			return -1;
 		}
 	}
 	atom->u.contents.option = C_TRAILERS;
-	string_list_clear(&params, 0);
 	return 0;
 }