some more protection from passing around and printing null values, we are now initializing null's passed to switch_caller_profile_new as blank strings in the caller profile, if your using any caller profile values in if's, please use !switch_strlen_zero() in your check.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@4203 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/include/switch_utils.h

@@ -199,6 +199,13 @@ switch_mutex_unlock(obj->flag_mutex);
 */
 #define switch_strlen_zero(s) (!s || *s == '\0')
 
+/*!
+  \brief Make a null string a blank string instead
+  \param s the string to test
+  \return the original string or blank string.
+*/
+#define switch_str_nil(s) (s ? s : "")
+
 /*!
   \brief Wait a desired number of microseconds and yield the CPU
 */