argv-array: add a new "pushl" method

It can be convenient to push many strings in a single line
(e.g., if you are initializing an array with defaults). This
patch provides a convenience wrapper to allow this.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Documentation/technical/api-argv-array.txt

@@ -37,6 +37,11 @@ Functions
 `argv_array_push`::
 	Push a copy of a string onto the end of the array.
 
+`argv_array_pushl`::
+	Push a list of strings onto the end of the array. The arguments
+	should be a list of `const char *` strings, terminated by a NULL
+	argument.
+
 `argv_array_pushf`::
 	Format a string and push it onto the end of the array. This is a
 	convenience wrapper combining `strbuf_addf` and `argv_array_push`.

argv-array.c

@@ -38,6 +38,17 @@ void argv_array_pushf(struct argv_array *array, const char *fmt, ...)
 	argv_array_push_nodup(array, strbuf_detach(&v, NULL));
 }
 
+void argv_array_pushl(struct argv_array *array, ...)
+{
+	va_list ap;
+	const char *arg;
+
+	va_start(ap, array);
+	while((arg = va_arg(ap, const char *)))
+		argv_array_push(array, arg);
+	va_end(ap);
+}
+
 void argv_array_clear(struct argv_array *array)
 {
 	if (array->argv != empty_argv) {

argv-array.h

@@ -15,6 +15,7 @@ void argv_array_init(struct argv_array *);
 void argv_array_push(struct argv_array *, const char *);
 __attribute__((format (printf,2,3)))
 void argv_array_pushf(struct argv_array *, const char *fmt, ...);
+void argv_array_pushl(struct argv_array *, ...);
 void argv_array_clear(struct argv_array *);
 
 #endif /* ARGV_ARRAY_H */