Fix fixed32/fixed64 and FieldMask handling in the CelValue runtime path

common/src/main/java/dev/cel/common/values/ProtoCelValueConverter.java

@@ -71,6 +71,18 @@ protected Object fromWellKnownProto(MessageLiteOrBuilder msg, WellKnownProto wel
               "Unpacking failed for message: " + message.getDescriptorForType().getFullName(), e);
         }
         return toRuntimeValue(unpackedMessage);
+      case FIELD_MASK:
+        // The base-class default converts FieldMask to a comma-separated string (its JSON wire
+        // form). That's correct when a FieldMask is being assigned to a google.protobuf.Value
+        // field (see ProtoLiteAdapter/CelProtoJsonAdapter, which handle JSON assignment at
+        // their own level), but it breaks CEL expressions that access fields on the FieldMask
+        // itself (e.g. `fieldMask.paths`) — the string has no field `paths`.
+        //
+        // The CEL spec's WKT conversion table does not list FieldMask. cel-go treats it as a
+        // regular message, as does cel-java's legacy ProtoLiteAdapter.adaptValueToWellKnownProto
+        // for non-JSON contexts. Preserve that behavior here by wrapping as a ProtoMessageValue.
+        return ProtoMessageValue.create(
+            (Message) message, celDescriptorPool, this, celOptions.enableJsonFieldNames());
       default:
         return super.fromWellKnownProto(message, wellKnownProto);
     }
@@ -154,11 +166,13 @@ public Object fromProtoMessageFieldToCelValue(Message message, FieldDescriptor f
 
         return toRuntimeValue(result);
       case UINT32:
+      case FIXED32:
         if (!fieldDescriptor.isRepeated()) {
           return UnsignedLong.valueOf((int) result);
         }
         break;
       case UINT64:
+      case FIXED64:
         if (!fieldDescriptor.isRepeated()) {
           return UnsignedLong.fromLongBits((long) result);
         }

common/src/test/java/dev/cel/common/values/ProtoMessageValueTest.java

@@ -303,6 +303,59 @@ public void selectField_durationOutOfRange_success(int seconds, int nanos) {
         .isEqualTo(Duration.ofSeconds(seconds, nanos));
   }
 
+  // The CEL spec maps proto's fixed32/fixed64 to CEL's uint. cel-java's checker (via
+  // DescriptorMappings) and its legacy DescriptorMessageProvider (via ProtoAdapter) both honor
+  // this. The CelValue path via ProtoCelValueConverter.fromProtoMessageFieldToCelValue used to
+  // miss FIXED32/FIXED64, falling through to normalizePrimitive and producing Integer/Long. That
+  // caused overload resolution to fail at runtime with "No matching overload" when the checker
+  // said uint but the runtime served a signed integer.
+  @Test
+  public void selectField_fixed32_returnsUnsignedLong() {
+    TestAllTypes testAllTypes = TestAllTypes.newBuilder().setSingleFixed32(1).build();
+
+    ProtoMessageValue protoMessageValue =
+        ProtoMessageValue.create(
+            testAllTypes, DefaultDescriptorPool.INSTANCE, PROTO_CEL_VALUE_CONVERTER, false);
+
+    assertThat(protoMessageValue.select("single_fixed32")).isEqualTo(UnsignedLong.valueOf(1L));
+  }
+
+  @Test
+  public void selectField_fixed64_returnsUnsignedLong() {
+    TestAllTypes testAllTypes =
+        TestAllTypes.newBuilder().setSingleFixed64(UnsignedLong.MAX_VALUE.longValue()).build();
+
+    ProtoMessageValue protoMessageValue =
+        ProtoMessageValue.create(
+            testAllTypes, DefaultDescriptorPool.INSTANCE, PROTO_CEL_VALUE_CONVERTER, false);
+
+    assertThat(protoMessageValue.select("single_fixed64")).isEqualTo(UnsignedLong.MAX_VALUE);
+  }
+
+  // FieldMask is not in the CEL spec's WKT conversion table and should be treated as a regular
+  // message so expressions like `fieldMask.paths` work. The base-class default
+  // (BaseProtoCelValueConverter) converts FieldMask to a comma-separated string in
+  // fromWellKnownProto; that's only correct in JSON-assignment contexts (handled separately by
+  // CelProtoJsonAdapter). ProtoCelValueConverter overrides to preserve FieldMask as a
+  // ProtoMessageValue so field selection continues to work.
+  @Test
+  public void selectField_fieldMask_returnsProtoMessageValue() {
+    TestAllTypes testAllTypes =
+        TestAllTypes.newBuilder()
+            .setFieldMask(
+                com.google.protobuf.FieldMask.newBuilder().addPaths("foo").addPaths("bar"))
+            .build();
+
+    ProtoMessageValue protoMessageValue =
+        ProtoMessageValue.create(
+            testAllTypes, DefaultDescriptorPool.INSTANCE, PROTO_CEL_VALUE_CONVERTER, false);
+
+    Object selected = protoMessageValue.select("field_mask");
+    assertThat(selected).isInstanceOf(ProtoMessageValue.class);
+    assertThat(((ProtoMessageValue) selected).select("paths"))
+        .isEqualTo(ImmutableList.of("foo", "bar"));
+  }
+
   @SuppressWarnings("ImmutableEnumChecker") // Test only
   private enum SelectFieldJsonValueTestCase {
     NULL(Value.newBuilder().build(), NullValue.NULL_VALUE),

publish/cel_version.bzl

@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """Maven artifact version for CEL."""
-CEL_VERSION = "0.13.0"
+CEL_VERSION = "0.13.0-planner-SNAPSHOT"