eina_str: add null check condition in eina_memdup.

Summary:
Added null check in eina_memdup function in eina_str

Signed-off-by: vivek <vivek.ellur@samsung.com>

Reviewers: cedric

Subscribers: cedric

Differential Revision: https://phab.enlightenment.org/D1997

Signed-off-by: Cedric BAIL <cedric@osg.samsung.com>

src/lib/eina/eina_str.c

@@ -668,8 +668,12 @@ eina_memdup(unsigned char *mem, size_t size, Eina_Bool terminate)
 {
    unsigned char *ret;
 
+   if (!mem) return NULL;
+
    terminate = !!terminate;
    ret = malloc(size + terminate);
+   if (!ret) return NULL;
+
    memcpy(ret, mem, size);
    if (terminate)
      ret[size] = 0;