diff --git a/CHANGELOG.md b/CHANGELOG.md
index b961882e..410dc887 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -130,6 +130,7 @@
 * Added Clixon example full system docker container, see [docker/system](docker/system).
 * Changed clixon base system container to use Alpine [docker/base](docker/base).
 * clixon-config YAML file has new revision: 2019-02-06.
+* Added new log function: `clicon_log_xml()` for logging XML tree
 * Replaced all calls to (obsolete) `cli_output` with `fprintf`
 * Added _experimental_ config option `CLICON_CLI_UTF8` default set to 0.
   * CLIgen UTF8 does not work with scrolling and control editing
diff --git a/apps/restconf/clixon_restconf.h b/apps/restconf/clixon_restconf.h
index a8625e9f..4c93c104 100644
--- a/apps/restconf/clixon_restconf.h
+++ b/apps/restconf/clixon_restconf.h
@@ -51,8 +51,6 @@ int notfound(FCGX_Request *r);
 int conflict(FCGX_Request *r);
 int internal_server_error(FCGX_Request *r);
 int notimplemented(FCGX_Request *r);
-
-int clicon_debug_xml(int dbglevel, char *str, cxobj *cx);
 int test(FCGX_Request *r, int dbg);
 cbuf *readdata(FCGX_Request *r);
 int get_user_cookie(char *cookiestr, char  *attribute, char **val);
diff --git a/apps/restconf/restconf_lib.c b/apps/restconf/restconf_lib.c
index fdf73f37..ec6689c4 100644
--- a/apps/restconf/restconf_lib.c
+++ b/apps/restconf/restconf_lib.c
@@ -284,26 +284,6 @@ notimplemented(FCGX_Request *r)
     return 0;
 }
 
-/*! Specialization of clicon_debug with xml tree */
-int 
-clicon_debug_xml(int    dbglevel, 
-		 char  *str,
-		 cxobj *x)
-{
-    int   retval = -1;
-    cbuf *cb;
-
-    if ((cb = cbuf_new()) == NULL)
-	goto done;
-    if (clicon_xml2cbuf(cb, x, 0, 0) < 0)
-	goto done;
-    clicon_debug(1, "%s %s", str, cbuf_get(cb));
-    retval = 0;
- done:
-    if (cb!=NULL)
-	cbuf_free(cb);
-    return retval;
-}
 
 /*!
  * @param[in]  r        Fastcgi request handle
diff --git a/apps/restconf/restconf_lib.h b/apps/restconf/restconf_lib.h
index 8c478370..57839bc8 100644
--- a/apps/restconf/restconf_lib.h
+++ b/apps/restconf/restconf_lib.h
@@ -56,7 +56,6 @@ int conflict(FCGX_Request *r);
 int internal_server_error(FCGX_Request *r);
 int notimplemented(FCGX_Request *r);
 
-int clicon_debug_xml(int dbglevel, char *str, cxobj *cx);
 int test(FCGX_Request *r, int dbg);
 cbuf *readdata(FCGX_Request *r);
 int get_user_cookie(char *cookiestr, char  *attribute, char **val);
diff --git a/lib/clixon/clixon_xml.h b/lib/clixon/clixon_xml.h
index da732586..5bcafe6b 100644
--- a/lib/clixon/clixon_xml.h
+++ b/lib/clixon/clixon_xml.h
@@ -179,5 +179,10 @@ int       xml_body_int32(cxobj *xb, int32_t *val);
 int       xml_body_uint32(cxobj *xb, uint32_t *val);
 int       xml_operation(char *opstr, enum operation_type *op);
 char     *xml_operation2str(enum operation_type op);
+#if defined(__GNUC__) && __GNUC__ >= 3
+int       clicon_log_xml(int level, cxobj *x, char  *format, ...)  __attribute__ ((format (printf, 3, 4)));
+#else
+int       clicon_log_xml(int level, cxobj *x, char  *format, ...);
+#endif
 
 #endif /* _CLIXON_XML_H */
diff --git a/lib/src/clixon_netconf_lib.c b/lib/src/clixon_netconf_lib.c
index 427e99fc..7f25330a 100644
--- a/lib/src/clixon_netconf_lib.c
+++ b/lib/src/clixon_netconf_lib.c
@@ -983,6 +983,11 @@ netconf_trymerge(cxobj       *x,
     char  *reason = NULL;
     cxobj *xc;
     
+    if (*xret == NULL){
+	if ((*xret = xml_dup(x)) == NULL)
+	    goto done;
+	goto ok;
+    }
     if (xml_merge(*xret, x, yspec, &reason) < 0)
 	goto done;
     if (reason){
@@ -993,6 +998,7 @@ netconf_trymerge(cxobj       *x,
 	retval = 1;
 	goto done;
     }
+ ok:
     retval = 0;
  done:
     if (reason)
diff --git a/lib/src/clixon_xml.c b/lib/src/clixon_xml.c
index f236c5f0..be277b3d 100644
--- a/lib/src/clixon_xml.c
+++ b/lib/src/clixon_xml.c
@@ -798,6 +798,7 @@ xml_cv_set(cxobj  *x,
  *
  * @retval xmlobj     if found.
  * @retval NULL       if no such node found.
+ * @see xml_find_type  wich is a more generic function
  */
 cxobj *
 xml_find(cxobj *x_up, 
@@ -987,7 +988,7 @@ xml_rm(cxobj *xc)
  *  # Here xt will be: <a>2</a>
  * @endcode
  * @see xml_child_rm
- * @see xml_child_rootchild_node  where xc is explicitly given
+ * @see xml_rootchild_node  where xc is explicitly given
  */
 int
 xml_rootchild(cxobj  *xp, 
@@ -1024,7 +1025,7 @@ xml_rootchild(cxobj  *xp,
  * @param[in]  xc   xml child node. Must be a child of xp
  * @retval     0    OK
  * @retval    -1    Error
- * @see xml_child_rootchild  where an index is used to find xc
+ * @see xml_rootchild  where an index is used to find xc
  */
 int
 xml_rootchild_node(cxobj  *xp, 
@@ -2188,6 +2189,61 @@ xml_operation2str(enum operation_type op)
     }
 }
 
+/*! Specialization of clicon_debug with xml tree 
+ * @param[in]  level    log level, eg LOG_DEBUG,LOG_INFO,...,LOG_EMERG. 
+ * @param[in]  x        XML tree that is logged without prettyprint
+ * @param[in]  format   Message to print as argv.
+*/
+int
+clicon_log_xml(int    level, 
+	       cxobj *x,
+	       char  *format, ...)
+{
+    va_list args;
+    int     len;
+    char   *msg = NULL;
+    cbuf   *cb = NULL;
+    int     retval = -1;
+
+    /* Print xml as cbuf */
+    if ((cb = cbuf_new()) == NULL)
+	goto done;
+    if (clicon_xml2cbuf(cb, x, 0, 0) < 0)
+	goto done;
+    
+    /* first round: compute length of debug message */
+    va_start(args, format);
+    len = vsnprintf(NULL, 0, format, args);
+    va_end(args);
+    
+    /* allocate a message string exactly fitting the message length */
+    if ((msg = malloc(len+1)) == NULL){
+	fprintf(stderr, "malloc: %s\n", strerror(errno)); /* dont use clicon_err here due to recursion */
+	goto done;
+    }
+
+    /* second round: compute write message from format and args */
+    va_start(args, format);
+    if (vsnprintf(msg, len+1, format, args) < 0){
+	va_end(args);
+	fprintf(stderr, "vsnprintf: %s\n", strerror(errno)); /* dont use clicon_err here due to recursion */
+	goto done;
+    }
+    va_end(args);
+
+    /* Actually log it */
+    clicon_log(level, "%s: %s", msg, cbuf_get(cb));
+
+    retval = 0;
+  done:
+    if (cb)
+	cbuf_free(cb);
+    if (msg)
+	free(msg);
+    return retval;
+}
+
+
 /*
  * Turn this on to get a xml parse and pretty print test program
  * Usage: xpath
diff --git a/lib/src/clixon_xml_map.c b/lib/src/clixon_xml_map.c
index c0babd4f..6a410510 100644
--- a/lib/src/clixon_xml_map.c
+++ b/lib/src/clixon_xml_map.c
@@ -2329,6 +2329,11 @@ xml_merge(cxobj     *x0,
     yang_stmt *ymod;
     cbuf      *cbr = NULL; /* Reason buffer */
 
+    if (x0 == NULL || x1 == NULL){
+	clicon_err(OE_UNIX, EINVAL, "parameters x0 or x1 is NULL");
+	goto done;
+	goto done;
+    }
     /* Loop through children of the modification tree */
     x1c = NULL;
     while ((x1c = xml_child_each(x1, x1c, CX_ELMNT)) != NULL) {
diff --git a/yang/clixon/clixon-config@2019-02-06.yang b/yang/clixon/clixon-config@2019-02-06.yang
index 4cb5bed0..57b457a3 100644
--- a/yang/clixon/clixon-config@2019-02-06.yang
+++ b/yang/clixon/clixon-config@2019-02-06.yang
@@ -135,7 +135,10 @@ module clixon-config {
 	leaf CLICON_CONFIGFILE{
 	    type string;
 	    description
-		"Location of configuration-file for default values (this file)";
+               "Location of configuration-file for default values (this file).
+                 Default is CLIXON_DEFAULT_CONFIG=/usr/local/etc/clicon.xml
+                 set in configure. Note that due to bootstrapping, a default
+                 value here does not work.";
 	}
 	leaf-list CLICON_YANG_DIR {
 	    ordered-by user;