--set-all: Ignore comments starting with #

opustags.1

@@ -97,7 +97,7 @@ Delete all the previously existing tags.
 Sets the tags from scratch.
 All the original tags are deleted and new ones are read from standard input.
 Each line must specify a \fIFIELD=VALUE\fP pair and be separated with line feeds.
-Blank lines are ignored.
+Blank lines and lines starting with \fI#\fP are ignored.
 .SH EXAMPLES
 .PP
 List all the tags in file foo.opus:

src/cli.cc

@@ -202,6 +202,8 @@ ot::status ot::read_comments(FILE* input, std::list<std::string>& comments)
 			--nread;
 		if (nread == 0)
 			continue;
+		if (line[0] == '#') // comment
+			continue;
 		if (memchr(line, '=', nread) == nullptr) {
 			ot::status rc = {ot::st::error, "Malformed tag: " + std::string(line, nread)};
 			free(line);

t/opustags.t

@@ -179,6 +179,7 @@ ARTIST=七面鳥
 
 A=A
 X=Y
+#IGNORE=COMMENTS
 END_IN
 OK=yes again
 ARTIST=七面鳥