🐛 FIX: Honor empty rule lists in custom presets

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Change Log
 
+## Unreleased
+
+* 🐛 Honor empty `rules` and `rules2` lists in custom presets by disabling every rule in the specified chain.
+
 ## 4.3.0 - 2026-11-10
 
 This release fixes two quadratic-time parsing paths that let crafted input stall rendering for minutes (security),

docs/using.md

@@ -67,6 +67,10 @@ from markdown_it.presets import zero
 zero.make()
 ```
 
+In a custom preset's `components`, an empty `rules` list disables all rules in that component.
+The same applies to `rules2` for inline post-processing rules.
+Omitting either list leaves the corresponding rules unchanged.
+
 ```{jupyter-execute}
 md = MarkdownIt("zero")
 md.options

markdown_it/main.py

@@ -131,10 +131,10 @@ def configure(
         if "components" in config:
             for name, component in config["components"].items():
                 rules = component.get("rules", None)
-                if rules:
+                if rules is not None:
                     self[name].ruler.enableOnly(rules)
                 rules2 = component.get("rules2", None)
-                if rules2:
+                if rules2 is not None:
                     self[name].ruler2.enableOnly(rules2)
 
         return self

tests/test_api/test_main.py

@@ -4,7 +4,7 @@
 
 import pytest
 
-from markdown_it import MarkdownIt
+from markdown_it import MarkdownIt, presets
 from markdown_it.token import Token
 
 if TYPE_CHECKING:
@@ -107,6 +107,34 @@ def test_override_options():
     assert md.options["maxNesting"] == 99
 
 
+def test_preset_empty_rules() -> None:
+    """An empty preset rule list disables the entire specified chain."""
+    for component, key, chain in (
+        ("core", "rules", "core"),
+        ("block", "rules", "block"),
+        ("inline", "rules", "inline"),
+        ("inline", "rules2", "inline2"),
+    ):
+        config = presets.commonmark.make()
+        config["components"][component][key] = []
+
+        md = MarkdownIt(config)
+
+        assert md.get_active_rules()[chain] == []
+
+
+def test_preset_empty_inline_rules_render_literal_text() -> None:
+    """Custom presets can disable all inline markup without individual names."""
+    config = presets.commonmark.make()
+    config["components"]["inline"]["rules"] = []
+
+    md = MarkdownIt(config)
+
+    assert md.renderInline("**bold** [link](https://example.com)") == (
+        "**bold** [link](https://example.com)"
+    )
+
+
 def test_gfm_like2_tasklists_editable():
     md_default = MarkdownIt("gfm-like2", GFM_LIKE2_OPTIONS)
     assert md_default.options["tasklists_editable"] is False