Add API call to determine if format capability structure is "empty".

Empty here means that there are no formats in the format_cap structure
or the only format in it is the "none" format.

I've added calls to check the emptiness of a format_cap in a few places
in order to short-circuit operations that would otherwise be pointless
as well as to prevent some assertions from being triggered in cases
where channels with no formats are used.



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/13@423414 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 15 insertions, 0 deletions

diff --git a/main/format_cap.c b/main/format_cap.c
index 65e469fc1..364c924bf 100644
--- a/main/format_cap.c
+++ b/main/format_cap.c
@@ -700,3 +700,18 @@ const char *ast_format_cap_get_names(struct ast_format_cap *cap, struct ast_str
 
 	return ast_str_buffer(*buf);
 }
+
+int ast_format_cap_empty(struct ast_format_cap *cap)
+{
+	int count = ast_format_cap_count(cap);
+
+	if (count > 1) {
+		return 0;
+	}
+
+	if (count == 0 || AST_VECTOR_GET(&cap->preference_order, 0)->format == ast_format_none) {
+		return 1;
+	}
+
+	return 0;
+}