feat(p1a): curate XmlReader/XmlWriter/JsonDocument as owned factories

frontend/roslyn/OwnSharp.Extractor/Program.cs

@@ -2260,9 +2260,15 @@
 //     IncrementalHash.CreateHash(), ... (guarded by static + Create-prefixed + the RESULT
 //     implementing IDisposable + the crypto namespace, so an instance `CreateEncryptor()` or
 //     a non-IDisposable `CreateFromName()` is never mistaken for one).
+//   * P1a stdlib pack: System.Xml `XmlReader.Create`/`XmlWriter.Create` -> a fresh owned
+//     reader/writer; System.Text.Json `JsonDocument.Parse` -> a JsonDocument that pools memory
+//     and must be disposed. Gated on the RESULT implementing IDisposable, so a Task-returning
+//     `JsonDocument.ParseAsync` is excluded.
 // Curated + symbol-resolved, so a borrowed/cached disposable handed back by some other API is
 // never mistaken for an owned acquire (precision over recall — the set grows only as
-// ownership is certain).
+// ownership is certain). Kept in lockstep with the bridge table `_BCL_FRESH_BY_NS`
+// (ownlang/ownir.py): the extractor decides whether to EMIT the factory call fact, the bridge
+// recognises the callee name as `fresh`.
 static bool IsOwningFactory(ExpressionSyntax? e, SemanticModel model)
 {
     if (e is not InvocationExpressionSyntax i
@@ -2278,6 +2284,35 @@
         && ImplementsIDisposable(sym.ReturnType)
         && IsInNamespace(sym.ContainingType, "System", "Security", "Cryptography"))
         return true;
+    if (sym.IsStatic && ImplementsIDisposable(sym.ReturnType)
+        && ((sym.Name == "Create"
+             && sym.ContainingType is { Name: "XmlReader" or "XmlWriter" } xt
+             && IsInNamespace(xt, "System", "Xml"))
+            || (sym.Name == "Parse"
+                && sym.ContainingType is { Name: "JsonDocument" } jt
+                && IsInNamespace(jt, "System", "Text", "Json")))
+        // ...but ONLY the overloads that take no disposable input. The Stream/TextReader/
+        // TextWriter overloads do NOT own that input (XmlReaderSettings.CloseInput /
+        // XmlWriterSettings.CloseOutput default false, JsonDocument.Parse never closes its
+        // stream), so claiming a pure factory there would let the escape pass drop the
+        // caller-owned input and suppress its leak (Codex). The common string/URI/path
+        // overloads have no disposable arg and still resolve. (precision over recall.)
+        && !AnyDisposableArgument(i, model))
+        return true;
+    return false;
+}
+
+// True if any argument to the call resolves to a type implementing IDisposable — a disposable
+// the callee might NOT take ownership of, so an enclosing owned-factory claim must be declined
+// rather than silently drop that argument from leak tracking.
+static bool AnyDisposableArgument(InvocationExpressionSyntax inv, SemanticModel model)
+{
+    foreach (var arg in inv.ArgumentList.Arguments)
+    {
+        var t = model.GetTypeInfo(arg.Expression).Type;
+        if (t is not null && ImplementsIDisposable(t))
+            return true;
+    }
     return false;
 }
 
@@ -2954,7 +2989,7 @@
     .Split(Path.PathSeparator, StringSplitOptions.RemoveEmptyEntries)
     .Where(p => p.EndsWith(".dll", StringComparison.OrdinalIgnoreCase))
     .ToList();
 var refNames = new HashSet<string>(tpa.Select(Path.GetFileName), StringComparer.OrdinalIgnoreCase);
 var references = tpa.Select(p => (MetadataReference)MetadataReference.CreateFromFile(p)).ToList();
 // P-004 WPF profile: widen the reference set with assemblies named by the
 // OWN_EXTRA_REF_DIRS env var (colon-separated dirs) — e.g. the WindowsDesktop ref

ownlang/ownir.py

@@ -1185,6 +1185,17 @@ def _infer_return_skeleton(nodes: Any, param_names: set[str],
         "SHA1.Create", "SHA256.Create", "SHA384.Create", "SHA512.Create", "MD5.Create",
         "Aes.Create", "RSA.Create", "ECDsa.Create",
     ),
+    # P1a (stdlib contract pack): more well-known static factories whose result the caller
+    # OWNS and must dispose. `XmlReader`/`XmlWriter.Create` return a fresh reader/writer; a
+    # `JsonDocument` from `Parse` pools memory and must be disposed (a `var doc =
+    # JsonDocument.Parse(json)` that drops `doc` is a common real leak). Kept in lockstep with
+    # the extractor's `IsOwningFactory` (frontend/roslyn/.../Program.cs).
+    "System.Xml": (
+        "XmlReader.Create", "XmlWriter.Create",
+    ),
+    "System.Text.Json": (
+        "JsonDocument.Parse",
+    ),
 }
 _BCL_FRESH_FACTORIES = frozenset(e for es in _BCL_FRESH_BY_NS.values() for e in es)
 # the fully-qualified identities (each under its real namespace), accepted beside the bare forms.

tests/test_ownir.py

@@ -1691,6 +1691,25 @@ def _bcl(body: list) -> list:
     if _bcl([{"op": "call", "callee": "global::MyCompany.File.OpenRead", "args": ["p"],
               "result": "s", "line": 4}]):
         fails.append("Tier B precision: `global::`-qualified non-System.IO must NOT match")
+    # P1a (stdlib pack): more curated owned-returning factories. A dropped XmlReader/XmlWriter/
+    # JsonDocument result leaks at the factory call (OWN001), the same producer-side contract as
+    # File.Open* — both the bare `Type.Method` and the namespace-qualified identity resolve.
+    for fresh_callee, ln in (("XmlReader.Create", 5),
+                             ("System.Xml.XmlReader.Create", 6),
+                             ("XmlWriter.Create", 7),
+                             ("System.Xml.XmlWriter.Create", 8),
+                             ("JsonDocument.Parse", 9),
+                             ("System.Text.Json.JsonDocument.Parse", 10)):
+        checks += 1
+        leak = [(x.code, x.line) for x in _bcl(
+            [{"op": "call", "callee": fresh_callee, "args": ["a"], "result": "s", "line": ln}])]
+        if leak != [("OWN001", ln)]:
+            fails.append(f"P1a: a leaked `{fresh_callee}` result must be OWN001@{ln}, got {leak}")
+    # disposing the P1a factory result is clean (no false leak), proving it is a real acquire.
+    checks += 1
+    if _bcl([{"op": "call", "callee": "XmlReader.Create", "args": ["a"], "result": "s", "line": 5},
+             {"op": "release", "var": "s", "line": 6}]):
+        fails.append("P1a: a disposed XmlReader.Create result must be clean (silent)")
     checks += 1
     # OVERRIDE (Codex): a first-party summary is authoritative — a first-party `File.OpenRead`
     # that returns its parameter is NOT fresh, so a caller dropping its result is clean; the