ci(doc-linter): fix RST code-block exit on short dedented lines

The dedent check inside `handle_file_action()` was

    if in_rst_codeblock:
        if len(line) > rst_codeblock_indent and not line[rst_codeblock_indent].isspace():
            in_rst_codeblock = False

This worked only when the next line was at least
`rst_codeblock_indent + 1` chars long — the indexing
`line[rst_codeblock_indent]` requires that. A short dedented
line (e.g., a single character at column 0 under a directive
indented at column 4) failed the length guard and `in_rst_codeblock`
stayed True. The block remained open longer than it should,
suppressing line-length checks on subsequent prose until either
EOF or the next `.. code-block::` reset the state.

Replace with a leading-whitespace-count check: on any non-blank
line, exit the block when leading-ws is <= the directive's
column. Blank lines don't reset the block context.

Test: a 3-line file with `.. code-block:: text` directive at col
0, one body line, a single `a` at col 0, then a 113-char line
at col 0. With the old logic the long line is still treated as
inside the code block and not flagged. With the new logic the
single-`a` dedent exits the block and the long line is flagged
as expected.

Tracked as items 6 and 12 of the rolling-side cleanup backlog
from PR #2014 / #2019 / #2020 reviews.

🤖 Generated by [robots](https://vyos.io)

(cherry picked from commit 6628b2901933f67568ba68617ee27c6f843c6dcf)

1 files changed, 15 insertions, 2 deletions

diff --git a/scripts/doc-linter.py b/scripts/doc-linter.py
index f4628c0b..fe262d98 100644
--- a/scripts/doc-linter.py
+++ b/scripts/doc-linter.py
@@ -180,8 +180,21 @@ def handle_file_action(filepath):
             # Each `.. code-block::` directive resets the tracked indent so a
             # later dedent past that column exits the block — even when the
             # directive itself appears inside an already-open outer block.
-            if in_rst_codeblock:
-                if len(line) > rst_codeblock_indent and not line[rst_codeblock_indent].isspace():
+            #
+            # Exit when the next non-blank line's leading-whitespace count is
+            # <= the directive's column. The body of an RST code-block must
+            # be indented MORE than the directive itself, so leading-ws at or
+            # below `rst_codeblock_indent` signals the block has ended.
+            #
+            # Previously this used `len(line) > rst_codeblock_indent and not
+            # line[rst_codeblock_indent].isspace()`, which silently skipped
+            # the exit check on lines shorter than `rst_codeblock_indent + 1`
+            # chars — e.g., a 3-char dedented line under a directive at
+            # column 4 left the block open, suppressing line-length checks
+            # downstream.
+            if in_rst_codeblock and line.strip():
+                leading = len(line) - len(line.lstrip())
+                if leading <= rst_codeblock_indent:
                     in_rst_codeblock = False
             if ".. code-block::" in line:
                 in_rst_codeblock = True