Keep UDH for concatenated SMS0.0.7

1 files changed, 15 insertions, 1 deletions

diff --git a/src/pdu_decode.c b/src/pdu_decode.c
index 643fa15..cbc2009 100644
--- a/src/pdu_decode.c
+++ b/src/pdu_decode.c
@@ -204,7 +204,21 @@ int pdu_decode_user_data(const char *pdu_str, struct pdu_info *pdu)
 	}
 
 	if (pdu->data_coding.general.alphabet == PDU_ALPHABET_DEFAULT) {
-		for (i = 0; i < pdu->user_data_len; i++) {
+		// Keep UDH for concatenated SMS.
+		// Otherwise it is impossible to process correctly concatenated SMS.
+		i = 0;
+		if (pdu->type.user_data_header) {
+			for (i = 0; i <= octets[0]; ++i) {
+				pdu->user_data[i] = octets[i];
+			}
+			i = octets[0] + 1; // Set message text start after UDH.
+			// Process octets padding for 7-bit encoding.
+			if (0 != (i * 8) % 7) {
+				pdu->user_data[i] = 0; // set padding data to 0;
+				i++;
+			}
+		}
+		for (; i < pdu->user_data_len; i++) {
 			pdu->user_data[i] = decode_septet(octets, i);
 		}
 		pdu->user_data[i] = '\0';