t.Fatalf("got %d headers, want %d headers", len(hdrs), len(v.headers))
			}

			for i, sum := range chksums {
				if i >= len(v.chksums) {
					t.Fatalf("entry %d: unexpected sum: got %s", i, sum)
				}
				if sum != v.chksums[i] {
					t.Fatalf("entry %d: incorrect checksum: got %s, want %s", i, sum, v.chksums[i])
				}
			}

			if err != v.err {
				t.Fatalf("unexpected error: got %v, want %v", err, v.err)

# SHA256 checksums of snapshot zip files in this directory.
# These checksums are included in the FIPS security policy
# (validation instructions sent to the lab) and MUST NOT CHANGE.
# That is, the zip files themselves must not change.
#
# It is okay to add new zip files to the list, and it is okay to
# remove zip files from the list when they are removed from
# this directory. To update this file:
#
#	go test cmd/go/internal/fips140 -update
#

                  <tarLongFileMode>gnu</tarLongFileMode>
                </configuration>
              </execution>
            </executions>
          </plugin>
          <!-- calculate checksums of source release for Apache dist area -->
          <plugin>
            <groupId>net.nicoulaj.maven.plugins</groupId>
            <artifactId>checksum-maven-plugin</artifactId>
            <version>1.11</version>

// DataOffset returns the offset of the file's possibly-compressed
// data, relative to the beginning of the zip file.
//
// Most callers should instead use [File.Open], which transparently
// decompresses data and verifies checksums.
func (f *File) DataOffset() (offset int64, err error) {
	bodyOffset, err := f.findBodyOffset()
	if err != nil {
		return
	}
	return f.headerOffset + bodyOffset, nil
}