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+CLAUDE.md
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diff --git a/CLAUDE.md b/CLAUDE.md
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@@ -0,0 +1,56 @@
+This file provides guidance to AI agents when working with code in this repository.
+
+Kothic is a MapCSS parser/processor tailored for Organic Maps. It compiles MapCSS stylesheets into the binary `drules_proto*.bin` (+ optional `.txt`) drawing-rule files that the renderer consumes, plus auxiliary metadata files (`classificator.txt`, `visibility.txt`, `colors.txt`, `patterns.txt`, `types.txt`).
+
+The parent project's `CLAUDE.md` (one level up at `omim/CLAUDE.md`) covers overall Organic Maps conventions; this file only documents kothic-specific details.
+
+## Commands
+
+```bash
+# Install deps (Python >= 3.8, protobuf ~3.20 — matches Ubuntu's python3-protobuf)
+pip3 install -r requirements.txt
+
+# Unit tests — discover all test*.py under tests/ (must run from project root)
+python3 -m unittest discover -s tests
+
+# Single test module / method
+python3 -m unittest tests.testLibkomwm
+python3 -m unittest tests.testLibkomwm.LibKomwmTest.test_generate_drules_mini
+
+# Lint (matches CI exactly — see .github/workflows/unit-tests.yml)
+ruff check --exclude=src/drules_struct_pb2.py --target-version=py39
+
+# Integration test — regenerates drules for all 6 themes from the real data/
+cd integration-tests && python3 full_drules_gen.py -d ../../../data -o drules --txt
+
+# Run the generator directly for one style
+python3 src/libkomwm.py -s <style.mapcss> -o <output_prefix> -p <priorities_dir> [--txt]
+
+# Full production regeneration (all 8 theme variants + merge) — run from anywhere
+../unix/generate_drules.sh
+```
+
+## Architecture
+
+**Entry point:** `src/libkomwm.py` — orchestrates the whole pipeline. `komap_mapswithme(options)` is the function callers (tests, `full_drules_gen.py`, `generate_drules.sh`) hook into. The bottom `main()` is the CLI wrapper.
+
+**Parser:** `src/mapcss/` — the MapCSS engine.
+- `__init__.py` defines the `MapCSS` class and all the regex-based tokenization (zoom, conditions, declarations, `@import`, variables).
+- `StyleChooser.py` — a single CSS-like rule block (selector + declaration). `MapCSS.parse()` produces a list of these.
+- `Rule.py` — one selector within a chooser (subject + zoom range + conditions). `type_matches` maps MapCSS subjects (`area`/`line`/`way`/`node`) to compatible geometry types.
+- `Condition.py` — a single `[tag=value]` predicate (eq/ne/lt/gt/regex/set/unset).
+- `Eval.py` — `eval('...')` MapCSS expressions, compiled to Python via `compile()`.
+- `webcolors/` — vendored color parsing (`whatever_to_hex`, `whatever_to_cairo`).
+
+**Protobuf output:** `src/drules_struct_pb2.py` is **auto-generated from `data/drules_struct.proto`** in the main repo — do not hand-edit. It defines `ContainerProto`, `ClassifElementProto`, `DrawElementProto`, etc. that `libkomwm` serializes.
+
+**Priority ranges** (see the long comment block near the top of `libkomwm.py`): drawing rules live in four ordered ranges — `overlays` (icons/captions, ±10000), `FG` (foreground areas/lines, 0–1000), `BG-top` (water, -1000–0), `BG-by-size` (landcover, -2000–-1000). The companion `priorities_*.prio.txt` files in `data/styles/<style>/include/` are **re-formatted and re-sorted in place** every time the generator runs; the renderer's layering logic in `drape_frontend/stylist.cpp` mirrors these ranges.
+
+**Test assets:** `tests/assets/` holds three case directories. `case-2-generate-drules-mini` is a stripped-down style (zooms 0–10, highway-only) whose generated output is checked for exact line/style counts — if you change the generator output format, those expected counts in `testLibkomwm.py` will need updating.
+
+## Conventions specific to kothic
+
+- This is a Python project inside a mostly-C++ repo; the parent `CLAUDE.md`'s C++ rules don't apply here. Follow PEP 8 / ruff defaults, target Python 3.9 (per CI).
+- `src/drules_struct_pb2.py` is auto-generated — never modify directly; regenerate from `data/drules_struct.proto`.
+- `libkomwm` carries module-level mutable state (`prio_ranges`, `visibilities`, `MULTIPROCESSING`). Tests and `full_drules_gen.py` `deepcopy` and restore it between runs — preserve that pattern if you add new global state.
+- Integration tests are not run by CI (`unit-tests.yml` only runs `unittest discover -s tests`). The integration script exists to verify the generator against the real `data/` styles.
diff --git a/src/mapcss/StyleChooser.py b/src/mapcss/StyleChooser.py
index d5da1d45..176dc23c 100644
--- a/src/mapcss/StyleChooser.py
+++ b/src/mapcss/StyleChooser.py
@@ -124,20 +124,29 @@ def get_runtime_conditions(self, tags):
 
     # TODO: Rename to "applyStyles"
     def updateStyles(self, sl, tags, xscale, zscale, filter_by_runtime_conditions):
-        # Are any of the ruleChains fulfilled?
-        rule_and_object_id = self.testChains(tags)
-
-        if not rule_and_object_id:
-            return sl
-
-        rule = rule_and_object_id[0]
-        object_id = rule_and_object_id[1]
+        # A single rule block can have comma-separated selectors that target
+        # different ::object-id subparts, e.g.
+        #     node|z16-[addr:housenumber][addr:street],
+        #     node|z16-[addr:housenumber][addr:street]::int_name,
+        #     {text: none;}
+        # Apply the body to every matching subpart (deduped by object-id), not
+        # just the first one — otherwise the other selectors silently keep
+        # whatever values the cascade brought in from earlier choosers.
+        seen_object_ids = set()
+        for rule in self.ruleChains:
+            object_id = rule.test(tags)
+            if not object_id or object_id in seen_object_ids:
+                continue
+            if (filter_by_runtime_conditions is not None
+                and rule.runtime_conditions is not None
+                and filter_by_runtime_conditions != rule.runtime_conditions):
+                continue
+            seen_object_ids.add(object_id)
+            self._applyBodyToObjectId(sl, tags, xscale, zscale, object_id)
 
-        if (filter_by_runtime_conditions is not None
-            and rule.runtime_conditions is not None
-            and filter_by_runtime_conditions != rule.runtime_conditions):
-            return sl
+        return sl
 
+    def _applyBodyToObjectId(self, sl, tags, xscale, zscale, object_id):
         for r in self.styles:
             if self.has_evals:
                 ra = {}
@@ -178,8 +187,6 @@ def updateStyles(self, sl, tags, xscale, zscale, filter_by_runtime_conditions):
                     allinit.update(ra)
                     sl.append(allinit)
 
-        return sl
-
     def testChains(self, tags):
         """
         Tests an object against a chain
diff --git a/tests/testStyleChooser.py b/tests/testStyleChooser.py
index c0784288..848af2bf 100644
--- a/tests/testStyleChooser.py
+++ b/tests/testStyleChooser.py
@@ -213,11 +213,11 @@ def test_update_styles_by_class(self):
         sc = StyleChooser((15, 19))
 
         sc.newObject()
-        sc.addCondition(Condition("eq", ("::class", "::flats") )) # `sc` styles should apply only to `::flats` class
+        sc.addCondition(Condition("eq", ("::class", "::flats") ))
         sc.addCondition(parseCondition("oneway?"))
 
         sc.newObject()
-        sc.addCondition(Condition("eq", ("::class", "::bridgeblack") )) # This class is ignored by StyleChooser
+        sc.addCondition(Condition("eq", ("::class", "::bridgeblack") ))
         sc.addCondition(parseCondition("oneway?"))
 
         sc.addStyles([{
@@ -227,19 +227,22 @@ def test_update_styles_by_class(self):
 
         object_tags = {"highway": "service", "oneway": "yes"}
 
-        # Apply new style to predefined styles with filter by class
+        # Apply new style to predefined styles. Both ::flats and ::bridgeblack
+        # selectors match (oneway=yes); body must be applied to each, leaving
+        # ::default — which has no matching ruleChain — alone.
         new_styles = sc.updateStyles(styles, object_tags, 1.0, 1.0, False)
 
-        expected_new_styles = [{ # The first style changes
+        expected_new_styles = [{
             "some-width": 1.5,
             "other-offset": 4.0,
             "object-id": "::flats"
         },
-        { # Style not changed (class is not `::flats`)
-            "some-width": 3.5,
+        {
+            "some-width": 1.5,
+            "other-offset": 4.0,
             "object-id": "::bridgeblack"
         },
-        { # Style not changed (class is not `::flats`)
+        { # No matching ruleChain for ::default
             "some-width": 4.5,
             "object-id": "::default"
         }]
@@ -291,5 +294,42 @@ def test_runtime_conditions(self):
         # TODO: Create test with  sc.addRuntimeCondition(Condition(condType, ('extra_tag', cond)))
         pass
 
+    def test_update_styles_multi_object_id(self):
+        """Regression: one rule block with comma-separated selectors targeting
+        different ::object-id subparts must apply the body to every matching
+        subpart, not just the first one. Mirrors the real-world case of:
+            node|z16-[addr:housenumber][addr:street],
+            node|z16-[addr:housenumber][addr:street]::int_name,
+            {text: none;}
+        """
+        # Predefined styles already in the cascade — both ::default and
+        # ::int_name come in with a populated text field that we want to clear.
+        styles = [
+            {"text": "name", "object-id": "::default"},
+            {"text": "int_name", "object-id": "::int_name"},
+        ]
+
+        sc = StyleChooser((15, 19))
+
+        sc.newObject()
+        sc.addCondition(parseCondition("addr:housenumber"))
+        sc.addCondition(parseCondition("addr:street"))
+
+        sc.newObject()
+        sc.addCondition(parseCondition("addr:housenumber"))
+        sc.addCondition(parseCondition("addr:street"))
+        sc.addCondition(Condition("eq", ("::class", "::int_name")))
+
+        sc.addStyles([{"text": "none"}])
+
+        tags = {"addr:housenumber": "12", "addr:street": "Baker street"}
+        new_styles = sc.updateStyles(styles, tags, 1.0, 1.0, False)
+
+        by_oid = {s["object-id"]: s for s in new_styles}
+        self.assertEqual(by_oid["::default"]["text"], "none")
+        self.assertEqual(by_oid["::int_name"]["text"], "none",
+                         "::int_name body must be applied even though "
+                         "::default selector matches first")
+
 if __name__ == '__main__':
     unittest.main()