diff --git a/protobuf/src/main/java/com/fasterxml/jackson/dataformat/protobuf/ProtobufParser.java b/protobuf/src/main/java/com/fasterxml/jackson/dataformat/protobuf/ProtobufParser.java
index dee473f1b..8baaeefd6 100644
--- a/protobuf/src/main/java/com/fasterxml/jackson/dataformat/protobuf/ProtobufParser.java
+++ b/protobuf/src/main/java/com/fasterxml/jackson/dataformat/protobuf/ProtobufParser.java
@@ -763,7 +763,10 @@ private JsonToken _handleRootKey(int tag) throws IOException
}
// array?
if (f.repeated) {
- if (f.packed) {
+ // 03-Jul-2026, tatu: [dataformats-binary#134] Decide packed-vs-unpacked from
+ // the actual wire type, not just the schema's declared `packed` flag:
+ // proto3 permits either encoding for repeated scalar/enum fields.
+ if (f.isPackedInWire(wireType)) {
_state = STATE_ARRAY_START_PACKED;
} else {
_state = STATE_ARRAY_START;
@@ -807,7 +810,10 @@ private JsonToken _handleNestedKey(int tag) throws IOException
// array?
if (f.repeated) {
- if (f.packed) {
+ // 03-Jul-2026, tatu: [dataformats-binary#134] Decide packed-vs-unpacked from
+ // the actual wire type, not just the schema's declared `packed` flag:
+ // proto3 permits either encoding for repeated scalar/enum fields.
+ if (f.isPackedInWire(wireType)) {
_state = STATE_ARRAY_START_PACKED;
} else {
_state = STATE_ARRAY_START;
@@ -1074,7 +1080,10 @@ public boolean nextFieldName(SerializableString sstr) throws IOException
// array?
if (_currentField.repeated) {
- if (_currentField.packed) {
+ // 03-Jul-2026, tatu: [dataformats-binary#134] Decide packed-vs-unpacked from
+ // the actual wire type, not just the schema's declared `packed` flag:
+ // proto3 permits either encoding for repeated scalar/enum fields.
+ if (_currentField.isPackedInWire(wireType)) {
_state = STATE_ARRAY_START_PACKED;
} else {
_state = STATE_ARRAY_START;
@@ -1110,7 +1119,10 @@ public boolean nextFieldName(SerializableString sstr) throws IOException
// array?
if (_currentField.repeated) {
- if (_currentField.packed) {
+ // 03-Jul-2026, tatu: [dataformats-binary#134] Decide packed-vs-unpacked from
+ // the actual wire type, not just the schema's declared `packed` flag:
+ // proto3 permits either encoding for repeated scalar/enum fields.
+ if (_currentField.isPackedInWire(wireType)) {
_state = STATE_ARRAY_START_PACKED;
} else {
_state = STATE_ARRAY_START;
@@ -1159,7 +1171,10 @@ public String nextFieldName() throws IOException
// array?
if (_currentField.repeated) {
- if (_currentField.packed) {
+ // 03-Jul-2026, tatu: [dataformats-binary#134] Decide packed-vs-unpacked from
+ // the actual wire type, not just the schema's declared `packed` flag:
+ // proto3 permits either encoding for repeated scalar/enum fields.
+ if (_currentField.isPackedInWire(wireType)) {
_state = STATE_ARRAY_START_PACKED;
} else {
_state = STATE_ARRAY_START;
@@ -1198,7 +1213,10 @@ public String nextFieldName() throws IOException
// array?
if (_currentField.repeated) {
- if (_currentField.packed) {
+ // 03-Jul-2026, tatu: [dataformats-binary#134] Decide packed-vs-unpacked from
+ // the actual wire type, not just the schema's declared `packed` flag:
+ // proto3 permits either encoding for repeated scalar/enum fields.
+ if (_currentField.isPackedInWire(wireType)) {
_state = STATE_ARRAY_START_PACKED;
} else {
_state = STATE_ARRAY_START;
diff --git a/protobuf/src/main/java/com/fasterxml/jackson/dataformat/protobuf/schema/ProtobufField.java b/protobuf/src/main/java/com/fasterxml/jackson/dataformat/protobuf/schema/ProtobufField.java
index 8a0e92c67..b0a4380e0 100644
--- a/protobuf/src/main/java/com/fasterxml/jackson/dataformat/protobuf/schema/ProtobufField.java
+++ b/protobuf/src/main/java/com/fasterxml/jackson/dataformat/protobuf/schema/ProtobufField.java
@@ -221,7 +221,34 @@ public final boolean isArray() {
public final boolean isValidFor(int typeTag) {
return (typeTag == wireType)
// 13-Apr-2017, tatu: to fix [dataformats-binary#76]
- || (packed && repeated && typeTag == WireType.LENGTH_PREFIXED);
+ // 03-Jul-2026, tatu: [dataformats-binary#134] A repeated scalar/enum
+ // field may arrive packed (LENGTH_PREFIXED) regardless of the schema's
+ // declared `packed` flag -- proto3 permits either encoding on the wire,
+ // so tolerance must key off the type, not the schema default.
+ || (repeated && type.isPackable() && typeTag == WireType.LENGTH_PREFIXED);
+ }
+
+ /**
+ * Accessor for deciding whether an incoming, repeated field should be read
+ * using "packed" (single length-prefixed block) encoding.
+ *
+ * For genuinely packable types (scalar numeric/enum/boolean) the native
+ * unpacked wire type differs from {@code LENGTH_PREFIXED}, so the actual wire
+ * type is unambiguous and authoritative: proto3 permits either encoding on the
+ * wire regardless of the schema's declared {@code packed} flag.
+ *
+ * For non-packable types (String/Bytes/Message) a single element and a
+ * jackson-style "packed" block are both {@code LENGTH_PREFIXED}, so the
+ * wire type cannot distinguish them; there we must fall back to the schema's
+ * declared {@code packed} flag.
+ *
+ * @since 2.21.5 [dataformats-binary#134]
+ */
+ public final boolean isPackedInWire(int typeTag) {
+ if (type.isPackable()) {
+ return repeated && (typeTag == WireType.LENGTH_PREFIXED);
+ }
+ return packed;
}
@Override
diff --git a/protobuf/src/test/java/com/fasterxml/jackson/dataformat/protobuf/Proto3PackedDefault134Test.java b/protobuf/src/test/java/com/fasterxml/jackson/dataformat/protobuf/Proto3PackedDefault134Test.java
index 4dd9a39dc..d07560cdc 100644
--- a/protobuf/src/test/java/com/fasterxml/jackson/dataformat/protobuf/Proto3PackedDefault134Test.java
+++ b/protobuf/src/test/java/com/fasterxml/jackson/dataformat/protobuf/Proto3PackedDefault134Test.java
@@ -116,4 +116,72 @@ public void testProto3WriteDefaultsToPacked() throws Exception
assertEquals(100, t.get("f").get(0).asInt());
assertEquals(200, t.get("f").get(1).asInt());
}
+
+ // [dataformats-binary#134]: even though a proto3 schema declares the field
+ // "packed" by default, the wire is authoritative -- an unpacked proto3 stream
+ // (legal per spec) must still decode. Decoder keys off the actual wire type.
+ @Test
+ public void testProto3PackedSchemaStillReadsUnpackedWire() throws Exception
+ {
+ final String SCHEMA_STR = "syntax = \"proto3\";\n"
+ + "message t {\n"
+ + " repeated uint32 f = 1;\n"
+ + "}\n";
+ // unpacked encoding despite proto3 default being packed
+ final byte[] pb = { 0x8, 0x64, 0x8, (byte) 0xc8, 0x1 }; // f = [100, 200], unpacked
+
+ ProtobufSchema schema = ProtobufSchemaLoader.std.parse(SCHEMA_STR);
+ JsonNode t = MAPPER.readerFor(JsonNode.class).with(schema).readValue(pb);
+
+ assertEquals(2, t.get("f").size());
+ assertEquals(100, t.get("f").get(0).asInt());
+ assertEquals(200, t.get("f").get(1).asInt());
+ }
+
+ // [dataformats-binary#134]: conversely, an unpacked-by-default schema (proto2,
+ // or proto3 with `[packed=false]`) must still decode a packed wire stream.
+ @Test
+ public void testUnpackedSchemaStillReadsPackedWire() throws Exception
+ {
+ final String SCHEMA_STR = "syntax = \"proto2\";\n"
+ + "message t {\n"
+ + " repeated uint32 f = 1;\n"
+ + "}\n";
+ // packed encoding despite proto2 default being unpacked
+ final byte[] pb = { 0xa, 0x3, 0x64, (byte) 0xc8, 0x1 }; // f = [100, 200], packed
+
+ ProtobufSchema schema = ProtobufSchemaLoader.std.parse(SCHEMA_STR);
+ JsonNode t = MAPPER.readerFor(JsonNode.class).with(schema).readValue(pb);
+
+ assertEquals(2, t.get("f").size());
+ assertEquals(100, t.get("f").get(0).asInt());
+ assertEquals(200, t.get("f").get(1).asInt());
+ }
+
+ // [dataformats-binary#134]: mismatch tolerance must also work for a repeated
+ // field nested inside a message (exercises `_handleNestedKey`, not just root).
+ // Uses proto2 + explicit `[packed=true]` to declare the nested field packed
+ // while feeding an unpacked wire stream (the old square protoparser does not
+ // accept proto3 singular message fields, so we avoid proto3 syntax here).
+ @Test
+ public void testNestedRepeatedPackedSchemaReadsUnpackedWire() throws Exception
+ {
+ final String SCHEMA_STR = "message Outer {\n"
+ + " optional Inner inner = 1;\n"
+ + "}\n"
+ + "message Inner {\n"
+ + " repeated uint32 f = 1 [packed=true];\n"
+ + "}\n";
+ // Outer.inner (field 1, length-delimited) wrapping Inner with unpacked f=[100,200]
+ // inner payload: 0x8,0x64, 0x8,0xc8,0x1 (5 bytes)
+ final byte[] pb = { 0xa, 0x5, 0x8, 0x64, 0x8, (byte) 0xc8, 0x1 };
+
+ ProtobufSchema schema = ProtobufSchemaLoader.std.parse(SCHEMA_STR, "Outer");
+ JsonNode t = MAPPER.readerFor(JsonNode.class).with(schema).readValue(pb);
+
+ JsonNode arr = t.get("inner").get("f");
+ assertEquals(2, arr.size());
+ assertEquals(100, arr.get(0).asInt());
+ assertEquals(200, arr.get(1).asInt());
+ }
}