From b0125b66116468b1e5d0dd2ee4eb0eebb4e7ecb4 Mon Sep 17 00:00:00 2001
From: Daniel-Constantin Mierla <miconda@gmail.com>
Date: Thu, 9 Sep 2021 10:27:01 +0200
Subject: [PATCH] presence: skip body operations on empty string

(cherry picked from commit c849070371740c01f9f13a889c610de9132349f3)
---
 src/modules/presence/notify.c       | 3 ++-
 src/modules/presence/presence_dmq.c | 3 +++
 src/modules/presence/presentity.c   | 6 ++++--
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/modules/presence/notify.c b/src/modules/presence/notify.c
index 87ed58cff41..cf52c21c221 100644
--- a/src/modules/presence/notify.c
+++ b/src/modules/presence/notify.c
@@ -1700,7 +1700,8 @@ int send_notify_request(
 	}
 
 	/* build extra headers */
-	if(build_str_hdr(subs, notify_body ? 1 : 0, &str_hdr) < 0) {
+	if(build_str_hdr(subs, (notify_body && notify_body->len>0) ? 1 : 0,
+				&str_hdr) < 0) {
 		LM_ERR("while building headers\n");
 		goto error;
 	}
diff --git a/src/modules/presence/presence_dmq.c b/src/modules/presence/presence_dmq.c
index 8dd7c99fe89..83a88f1aa14 100644
--- a/src/modules/presence/presence_dmq.c
+++ b/src/modules/presence/presence_dmq.c
@@ -303,6 +303,9 @@ int pres_dmq_handle_msg(
 		} else if(strcmp(it->string, "body") == 0) {
 			p_body.s = it->valuestring;
 			p_body.len = strlen(it->valuestring);
+			if(p_body.len==0) {
+				p_body.s = NULL;
+			}
 		} else {
 			LM_ERR("unrecognized field in json object\n");
 			goto invalid;
diff --git a/src/modules/presence/presentity.c b/src/modules/presence/presentity.c
index bc17bf10748..a7629a4e920 100644
--- a/src/modules/presence/presentity.c
+++ b/src/modules/presence/presentity.c
@@ -737,6 +737,7 @@ static int ps_db_update_presentity(sip_msg_t *msg, presentity_t *presentity,
 	result_cols[rez_ruid_col = n_result_cols++] = &str_ruid_col;
 
 	if(new_t) {
+		/* new_t!=0 */
 		LM_DBG("new presentity with etag %.*s\n", presentity->etag.len,
 				presentity->etag.s);
 
@@ -888,6 +889,7 @@ static int ps_db_update_presentity(sip_msg_t *msg, presentity_t *presentity,
 			*sent_reply = 1;
 		goto send_notify;
 	} else {
+		/* new_t==0 */
 		LM_DBG("updating existing presentity with etag %.*s\n",
 				presentity->etag.len, presentity->etag.s);
 
@@ -1206,7 +1208,7 @@ static int ps_db_update_presentity(sip_msg_t *msg, presentity_t *presentity,
 		update_vals[n_update_cols].val.int_val = presentity->priority;
 		n_update_cols++;
 
-		if(body && body->s) {
+		if(body && body->s && body->len>0) {
 			update_keys[n_update_cols] = &str_body_col;
 			update_vals[n_update_cols].type = DB1_BLOB;
 			update_vals[n_update_cols].nul = 0;
@@ -1748,7 +1750,7 @@ static int ps_cache_update_presentity(sip_msg_t *msg, presentity_t *presentity,
 		ptc.expires = presentity->expires + (int)time(NULL);
 		ptc.received_time = presentity->received_time;
 		ptc.priority = presentity->priority;
-		if(body && body->s) {
+		if(body && body->s && body->len>0) {
 			ptc.body = *body;
 		}
 		if(presentity->sender) {