[IOS-XR] indent_adjust rule for "template" corrupts indentation when used as leaf param inside flow exporter-map

[Kani999]

Version

hier-config 3.4.1

Platform

Platform.CISCO_XR

Error

DuplicateChildError: Found a duplicate section: ('flow exporter-map EXPORTER1', 'route-policy POLICY1', 'endif')

Minimal Reproduction

from hier_config import get_hconfig, Platform

text = '''flow exporter-map EXPORTER1
 version v9
  template timeout 60
 !
 transport udp 9999
!
route-policy POLICY1
  if (destination in PREFIX-SET1) then
    drop
  endif
  if (destination in PREFIX-SET2) then
    done
  endif
  drop
end-policy
!
'''
get_hconfig(Platform.CISCO_XR, text)

Stack trace:

File ".../hier_config/base.py", line 86, in add_child
    raise DuplicateChildError(message)
hier_config.exceptions.DuplicateChildError: Found a duplicate section: ('flow exporter-map EXPORTER1', 'route-policy POLICY1', 'endif')

Root Cause Analysis

The IOS-XR driver defines an indent_adjust rule in hier_config/platforms/cisco_xr/driver.py (lines 106–110):

• start_expression="^\s*template" → increments indent_adjust by 1
• end_expression="^\s*end-template" → decrements it back

In flow exporter-map blocks, IOS-XR uses template timeout 60 as a leaf parameter — it is not a block opener and has no matching end-template. When the parser encounters this line:

1. indent_adjust is incremented to +1.
2. No end-template ever follows, so indent_adjust is permanently stuck at +1 for the remainder of the file.
3. All subsequent top-level blocks (route-policy POLICY1, etc.) are parsed as if they are children of the last open block (flow exporter-map EXPORTER1).
4. parent_allows_duplicate_child only permits duplicates when the direct parent starts with "route-policy" — but the parent is now flow exporter-map EXPORTER1, so endif appearing twice raises DuplicateChildError.

Suggested Fix Options

Option 1 — Narrow the start_expression to exclude template timeout (and similar leaf forms):

start_expression=r"^\s*template(?!\s+timeout)"

This uses a negative lookahead so lines like template timeout 60 no longer trigger the indent increment.

Option 2 — Scope the rule so it only fires when the current parent context is a template block:

Require the enclosing parent to be a template definition before bumping indent_adjust, avoiding false positives from leaf uses of the template keyword in other block types.

Driver File

hier_config/platforms/cisco_xr/driver.py, lines 106–110