fixed an edge-case bug preventing generation of helpful error message…

…s in response to non-sensical user input (eg "@atom:")

moltemplate/scripts/moltemplate.sh

@@ -6,8 +6,8 @@
 # Copyright (c) 2013
 
 G_PROGRAM_NAME="moltemplate.sh"
-G_VERSION="2.18.4"
-G_DATE="2020-8-05"
+G_VERSION="2.18.5"
+G_DATE="2020-8-06"
 
 echo "${G_PROGRAM_NAME} v${G_VERSION} ${G_DATE}" >&2
 echo "" >&2

moltemplate/ttree.py

@@ -102,8 +102,8 @@
 g_module_name = g_filename
 if g_filename.rfind('.py') != -1:
     g_module_name = g_filename[:g_filename.rfind('.py')]
-g_date_str = '2020-8-05'
-g_version_str = '0.86.5'
+g_date_str = '2020-8-06'
+g_version_str = '0.86.6'
 
 
 class ClassReference(object):
@@ -872,6 +872,7 @@ def FollowPathCounterVar(leaf_ptkns, starting_node, dbg_loc):
 
     is_static_node = isinstance(starting_node, StaticObj)
 
+    assert(len(leaf_ptkns) > 0)
     if is_static_node:
         is_simple_node = ((len(last_node.children) == 0) and
                           (len(last_node.instance_commands) == 0) and
@@ -1435,6 +1436,12 @@ def DescrToCatLeafNodes(descr_str, context_node, dbg_loc):
 
     cat_name, cat_ptkns, leaf_ptkns = DescrToCatLeafPtkns(descr_str, dbg_loc)
 
+    if len(leaf_ptkns) == 0:
+        raise InputError('Error(' + g_module_name + '.DescrToCatLeafNodes()):\n'
+                         '       Error near ' +
+                         ErrorLeader(dbg_loc.infile, dbg_loc.lineno) + '\n'
+                         '       Illegal counter variable \"' + descr_str + '\"\n')
+
     # ---- ellipsis hack ----
     #
     # Search for class:

setup.py

@@ -45,9 +45,9 @@
 
   url='https://github.com/jewettaij/moltemplate',
 
-  download_url='https://github.com/jewettaij/moltemplate/archive/v2.18.4.zip',
+  download_url='https://github.com/jewettaij/moltemplate/archive/v2.18.5.zip',
 
-  version='2.18.4',
+  version='2.18.5',
 
   keywords=['simulation', 'LAMMPS', 'molecule editor', 'molecule builder',
             'ESPResSo'],