- fixed EditSG reservation

src/iec61850/server/mms_mapping/mms_mapping.c

@@ -1714,7 +1714,9 @@ mmsWriteHandler(void* parameter, MmsDomain* domain,
                 if (sg != NULL) {
                     uint32_t val = MmsValue_toUint32(value);
 
-                    if (sg->editingClient == (ClientConnection) connection) {
+                    if ((sg->editingClient != NULL) && ( sg->editingClient != (ClientConnection) connection))
+                    	/* Edit SG was set by other client */
+                    	return DATA_ACCESS_ERROR_TEMPORARILY_UNAVAILABLE;
 
 					if (val == 0) {
 						unselectEditSettingGroup(sg);
@@ -1750,9 +1752,7 @@ mmsWriteHandler(void* parameter, MmsDomain* domain,
 					}
 					else
 						return DATA_ACCESS_ERROR_OBJECT_VALUE_INVALID;
-                    }
-                    else /* Edit SG was set by other client */
-                    	return DATA_ACCESS_ERROR_TEMPORARILY_UNAVAILABLE;
+
                 }
             }
             else if (strcmp(nameId, "CnfEdit") == 0) {