From e71012814800462519b9040e82c892dfa39bf817 Mon Sep 17 00:00:00 2001
From: Daniel-Constantin Mierla <miconda@gmail.com>
Date: Thu, 14 May 2015 14:29:12 +0200
Subject: [PATCH] textops: safety check to know there is a string to add via
 lump

(cherry picked from commit ca220afe0f738f2353d16c96dd16ab279ffdcf74)
---
 modules/textops/textops.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/modules/textops/textops.c b/modules/textops/textops.c
index a945937b3a5..fa8874ffac6 100644
--- a/modules/textops/textops.c
+++ b/modules/textops/textops.c
@@ -2126,6 +2126,11 @@ int add_hf_helper(struct sip_msg* msg, str *str1, str *str2,
 	len=s0.len;
 	if (str2) len+= str2->len + REQ_LINE(msg).uri.len;
 
+	if(len==0) {
+		LM_INFO("nothing to add\n");
+		return -1;
+	}
+
 	s  = (char*)pkg_malloc(len);
 	if (!s) {
 		LM_ERR("no pkg memory left\n");