3 files changed, 101 insertions, 0 deletions
diff --git a/third_party/zip/Android.bp b/third_party/zip/Android.bp
index 044e6f8e..ec89c0c0 100644
--- a/third_party/zip/Android.bp
+++ b/third_party/zip/Android.bp
@@ -24,6 +24,7 @@ bootstrap_go_package {
         "android.go",
     ],
     testSrcs: [
+        "android_test.go",
         "reader_test.go",
         "writer_test.go",
         "zip_test.go",
diff --git a/third_party/zip/android.go b/third_party/zip/android.go
index e2e46ffd..f3b60555 100644
--- a/third_party/zip/android.go
+++ b/third_party/zip/android.go
@@ -32,6 +32,12 @@ func (w *Writer) CopyFrom(orig *File, newName string) error {
 	fh := &fileHeader
 	fh.Flags |= 0x8
 
+	// The zip64 extras change between the Central Directory and Local File Header, while we use
+	// the same structure for both. The Local File Haeder is taken care of by us writing a data
+	// descriptor with the zip64 values. The Central Directory Entry is written by Close(), where
+	// the zip64 extra is automatically created and appended when necessary.
+	fh.Extra = stripZip64Extras(fh.Extra)
+
 	h := &header{
 		FileHeader: fh,
 		offset:     uint64(w.cw.count),
@@ -70,6 +76,29 @@ func (w *Writer) CopyFrom(orig *File, newName string) error {
 	return err
 }
 
+// Strip any Zip64 extra fields
+func stripZip64Extras(input []byte) []byte {
+	ret := []byte{}
+
+	for len(input) >= 4 {
+		r := readBuf(input)
+		tag := r.uint16()
+		size := r.uint16()
+		if int(size) > len(r) {
+			break
+		}
+		if tag != zip64ExtraId {
+			ret = append(ret, input[:4+size]...)
+		}
+		input = input[4+size:]
+	}
+
+	// Keep any trailing data
+	ret = append(ret, input...)
+
+	return ret
+}
+
 // CreateCompressedHeader adds a file to the zip file using the provied
 // FileHeader for the file metadata.
 // It returns a Writer to which the already compressed file contents
diff --git a/third_party/zip/android_test.go b/third_party/zip/android_test.go
new file mode 100644
index 00000000..cdf66ff6
--- /dev/null
+++ b/third_party/zip/android_test.go
@@ -0,0 +1,71 @@
+// Copyright 2017 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zip
+
+import (
+	"bytes"
+	"testing"
+)
+
+var stripZip64Testcases = []struct {
+	name string
+	in   []byte
+	out  []byte
+}{
+	{
+		name: "empty",
+		in:   []byte{},
+		out:  []byte{},
+	},
+	{
+		name: "trailing data",
+		in:   []byte{1, 2, 3},
+		out:  []byte{1, 2, 3},
+	},
+	{
+		name: "valid non-zip64 extra",
+		in:   []byte{2, 0, 2, 0, 1, 2},
+		out:  []byte{2, 0, 2, 0, 1, 2},
+	},
+	{
+		name: "two valid non-zip64 extras",
+		in:   []byte{2, 0, 2, 0, 1, 2, 2, 0, 0, 0},
+		out:  []byte{2, 0, 2, 0, 1, 2, 2, 0, 0, 0},
+	},
+	{
+		name: "simple zip64 extra",
+		in:   []byte{1, 0, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8},
+		out:  []byte{},
+	},
+	{
+		name: "zip64 extra and valid non-zip64 extra",
+		in:   []byte{1, 0, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 2, 0, 0, 0},
+		out:  []byte{2, 0, 0, 0},
+	},
+	{
+		name: "invalid extra",
+		in:   []byte{0, 0, 8, 0, 0, 0},
+		out:  []byte{0, 0, 8, 0, 0, 0},
+	},
+}
+
+func TestStripZip64Extras(t *testing.T) {
+	for _, testcase := range stripZip64Testcases {
+		got := stripZip64Extras(testcase.in)
+		if !bytes.Equal(got, testcase.out) {
+			t.Errorf("Failed testcase %s\ninput: %v\n want: %v\n  got: %v\n", testcase.name, testcase.in, testcase.out, got)
+		}
+	}
+}