terminal: Fix IndexError when attempting to elide paths with empty components

IPython/terminal/ptutils.py

@@ -47,10 +47,10 b' def _elide_point(string:str, *, min_elide=30)->str:'
     if file_parts[-1] == '':
         file_parts.pop()
 
-    if len(object_parts) > 3:
+    if len(object_parts) > 3 and object_parts[1] and object_parts[-2]:
         return '{}.{}\N{HORIZONTAL ELLIPSIS}{}.{}'.format(object_parts[0], object_parts[1][0], object_parts[-2][-1], object_parts[-1])
 
-    elif len(file_parts) > 3:
+    elif len(file_parts) > 3 and file_parts[1] and file_parts[-2]:
         return ('{}' + os.sep + '{}\N{HORIZONTAL ELLIPSIS}{}' + os.sep + '{}').format(file_parts[0], file_parts[1][0], file_parts[-2][-1], file_parts[-1])
 
     return string