Fix case-insensitive MuPDF detail path collision

Author: zhaobozhen

docs/rules-v5-contract.md

@@ -24,9 +24,12 @@ Each matcher has the following **required** fields:
 - `priority`: nonnegative integer, lower first; import uses legacy `_id`.
 - `label`: original DB display label, independent of localized details.
 - `iconId`: stable `ic_lib_*` string or null; explicit per-matcher value.
-- `regexName`: original string or null, used only for compatibility paths.
+- `regexName`: compatibility detail alias or null; a nonempty alias makes Android
+  request `<type-dir>/regex/<regexName>.json`, including for `exact` matchers.
+  It does not change `name` or matching mode.
 - `hasDetail`: boolean; false means no details, even if library `data` exists.
-- `legacyPath`: original detail path or null.
+- `legacyPath`: compatibility detail path or null; must agree with the client's
+  request path, including any `regexName` alias.
 - `examples`: `{positive: [string], negative: [string]}`; empty arrays permitted for
   imported patterns without trustworthy examples, never invented witnesses.
 
@@ -93,6 +96,13 @@ legacy files are retained during migration; new source edits ship updated legacy
 artifacts from the same compiler invocation. Orphan descriptions remain available
 at old paths without becoming matches.
 
+`load_source` rejects distinct legacy detail paths whose `casefold()` values are
+equal, so generated files can coexist on case-insensitive filesystems. Use a
+distinct detail alias when exact names differ only by case; keep their matching
+names unchanged. Publish a detail path change together with the updated rules DB.
+Removing the old path makes its detail unavailable to clients still using the old
+DB until they update their rules; a path rename is not seamless compatibility.
+
 ## Matching and SVG safety
 
 Exact name equality is attempted first for **all rows**, including the literal

libraries/D100E2DE-D729-4D97-A66E-8B51A090ED5B.json

@@ -39,9 +39,9 @@
       "priority": 1773,
       "label": "MuPDF",
       "iconId": null,
-      "regexName": null,
+      "regexName": "mupdf_uppercase",
       "hasDetail": true,
-      "legacyPath": "native-libs/libMuPDF.so.json",
+      "legacyPath": "native-libs/regex/mupdf_uppercase.json",
       "examples": {
         "positive": [
           "libMuPDF.so"

native-libs/libMuPDF.so.json native-libs/regex/mupdf_uppercase.jsonnative-libs/libMuPDF.so.json renamed to native-libs/regex/mupdf_uppercase.json

@@ -30,6 +30,35 @@ def test_source_details_and_exact_lookup(self):
                 self.assertEqual(row['uuid'],detail['uuid'])
                 self.assertTrue(detail['data'])
 
+    def test_mupdf_case_distinct_names_and_detail_paths(self):
+        for name,id,legacy_path,alias in [('libMuPDF.so',1773,'native-libs/regex/mupdf_uppercase.json','mupdf_uppercase'),
+                                          ('libmupdf.so',3090,'native-libs/libmupdf.so.json',None)]:
+            row=next(row for row in self.rows if row['id']==id)
+            self.assertFalse(row['isRegexRule'])
+            self.assertEqual(alias,row['regexName'])
+            for use_regex in (False,True):
+                self.assertEqual(id,rules.find_rule(self.rows,name,0,use_regex))
+            self.assertEqual(self.common[row['detailPath']],self.legacy[legacy_path])
+        self.assertNotIn('native-libs/libMuPDF.so.json',self.legacy)
+
+    def test_legacy_paths_reject_case_collisions_and_allow_identical_reuse(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            root=Path(tmp);shutil.copytree(ROOT/'icons',root/'icons');(root/'libraries').mkdir()
+            filename='D100E2DE-D729-4D97-A66E-8B51A090ED5B.json'
+            original=rules.read(ROOT/'libraries'/filename);path=root/'libraries'/filename
+            for source in ('matcher','orphan'):
+                with self.subTest(source=source):
+                    lib=copy.deepcopy(original)
+                    if source=='matcher':lib['matchers'][0]['legacyPath']='native-libs/libMuPDF.so.json'
+                    else:lib['unreferencedDescriptions']=[dict(path='native-libs/libMuPDF.so.json',payload=dict(uuid=lib['uuid'],data=lib['data']))]
+                    path.write_bytes(rules.encoded(lib))
+                    with self.assertRaisesRegex(ValueError,'Case-insensitive legacy path collision'):rules.load_source(root)
+            lib=copy.deepcopy(original)
+            lib['unreferencedDescriptions']=[dict(path=lib['matchers'][0]['legacyPath'],payload=dict(uuid=lib['uuid'],data=lib['data']))]
+            path.write_bytes(rules.encoded(lib))
+            _,_,legacy,_=rules.load_source(root)
+            self.assertEqual(2,len(legacy))
+
     def test_reproducible_build_and_versioning(self):
         with tempfile.TemporaryDirectory() as tmp,contextlib.redirect_stdout(io.StringIO()):
             a,b=Path(tmp)/'a',Path(tmp)/'b'

tests/test_rules.py

@@ -149,10 +149,11 @@ def load_source(root=ROOT):
         raw=path.read_bytes();generated=validate_vector(raw,path.stem)
         fail(icons.get(f'icons/{path.stem}.svg')==generated,f'SVG must be derived from Android XML: {path.stem}')
         vectors[f'icons/android/{path.name}']=raw
-    libraries=[];rules=[];details={};legacy={};ids=set();names=set()
+    libraries=[];rules=[];details={};legacy={};legacy_names={};ids=set();names=set()
     def add_legacy(path,payload):
         safe_path(path)
         fail(path.split('/')[0] in ('native-libs','services-libs','activities-libs','receivers-libs','providers-libs','dex-libs','static-libs','permissions-libs','metadata-libs','actions-libs') and path.endswith('.json'),'Invalid legacy detail path')
+        fail(legacy_names.setdefault(path.casefold(),path)==path,f'Case-insensitive legacy path collision: {legacy_names[path.casefold()]} and {path}')
         value=encoded(payload)
         fail(path not in legacy or legacy[path]==value,f'Conflicting legacy details: {path}')
         legacy[path]=value