Write out rewritten SDP from answer to metadata file

daemon/call_interfaces.c

@@ -740,6 +740,12 @@ static const char *call_offer_answer_ng(bencode_item_t *input, struct callmaster
 		chopper->iov_num, chopper->str_len);
 	bencode_dictionary_add_string(output, "result", "ok");
 
+	struct recording *recording = call->recording;
+	if (opmode == OP_ANSWER && call->record_call && recording != NULL && recording->meta_fp != NULL) {
+		struct iovec *iov = &g_array_index(chopper->iov, struct iovec, 0);
+		int iovcnt = chopper->iov_num;
+		meta_write_sdp(recording->meta_fp, iov, iovcnt);
+	}
 	bencode_dictionary_get_str(input, "metadata", &metadata);
 	if (metadata.len > 0 && call->recording != NULL) {
 		if (call->recording->metadata != NULL) {

daemon/recording.c

@@ -184,6 +184,19 @@ str *meta_setup_file(struct recording *recording, str callid) {
 	}
 }
 
+/**
+ * Write out a block of SDP to the metadata file.
+ */
+ssize_t meta_write_sdp(FILE *meta_fp, struct iovec *sdp_iov, int iovcnt) {
+	fprintf(meta_fp, "\n");
+	int meta_fd = fileno(meta_fp);
+	// File pointers buffer data, whereas direct writing using the file
+	// descriptor does not. Make sure to flush any unwritten contents
+	// so the file contents appear in order.
+	fflush(meta_fp);
+	writev(meta_fd, sdp_iov, iovcnt);
+}
+
 /**
  * Writes metadata to metafile, closes file, and renames it to finished location.
  * Returns non-zero for failure.

daemon/recording.h

@@ -63,6 +63,11 @@ int detect_setup_recording(struct call *call, str recordcall);
  */
 str *meta_setup_file(struct recording *recording, str callid);
 
+/**
+ * Write out a block of SDP to the metadata file.
+ */
+ssize_t meta_write_sdp(FILE *meta_fp, struct iovec *sdp_iov, int iovcnt);
+
 /**
  * Writes metadata to metafile, closes file, and moves it to finished location.
  * Returns non-zero for failure.