updated for version 7.3.683
Problem:    ":python" may crash when vimbindeval() returns None.
Solution:   Check for v_string to be NULL. (Yukihiro Nakadaira)
diff --git a/src/if_py_both.h b/src/if_py_both.h
index 0a1ef1b..2398e81 100644
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -351,7 +351,8 @@
 
     if (our_tv->v_type == VAR_STRING)
     {
-	result = Py_BuildValue("s", our_tv->vval.v_string);
+	result = Py_BuildValue("s", our_tv->vval.v_string == NULL
+					? "" : (char *)our_tv->vval.v_string);
     }
     else if (our_tv->v_type == VAR_NUMBER)
     {
@@ -2751,7 +2752,8 @@
     switch (tv->v_type)
     {
 	case VAR_STRING:
-	    return PyBytes_FromString((char *) tv->vval.v_string);
+	    return PyBytes_FromString(tv->vval.v_string == NULL
+					    ? "" : (char *)tv->vval.v_string);
 	case VAR_NUMBER:
 	    return PyLong_FromLong((long) tv->vval.v_number);
 #ifdef FEAT_FLOAT
@@ -2763,7 +2765,8 @@
 	case VAR_DICT:
 	    return DictionaryNew(tv->vval.v_dict);
 	case VAR_FUNC:
-	    return FunctionNew(tv->vval.v_string);
+	    return FunctionNew(tv->vval.v_string == NULL
+					  ? (char_u *)"" : tv->vval.v_string);
 	case VAR_UNKNOWN:
 	    Py_INCREF(Py_None);
 	    return Py_None;
diff --git a/src/version.c b/src/version.c
index 143657e..62e0f4b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -720,6 +720,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    683,
+/**/
     682,
 /**/
     681,