Keep the colleague's microbu-esp32c5 tree in this repository

obu-firmware builds against vanetza-idf from microbu-esp32c5/external, but
that tree was gitignored, so a clone of this repository could not build the
firmware it ships. It is now committed here as ordinary files in its own
folder, microbu-esp32c5/: the colleague's commit cf4b99f plus the V2X2MAP
bridge's signature verification (--trust) used on the bench. Nothing is
fetched from or pushed to the colleague's repository; this repository and
its remotes carry everything. The folder's own .gitignore keeps build output,
downloaded components and private key material out, as it did there; the
committed file set is identical to that repository's tracked files.

The ESP32-C5 is still flashed from obu-firmware/, which only takes
vanetza-idf from microbu-esp32c5/, so the two stay separate folders.
FLASHING.md says how to take a newer version of the colleague's tree (copy
it over the folder, rebuild, test, commit).

microbu-esp32c5/external/vanetza-idf/vanetza/net/tests/chunk_packet.cpp

@@ -0,0 +1,145 @@
+#include <gtest/gtest.h>
+#include <vanetza/net/chunk_packet.hpp>
+
+using vanetza::ByteBuffer;
+using vanetza::ChunkPacket;
+using vanetza::OsiLayer;
+
+TEST(ChunkPacket, ctor)
+{
+    ChunkPacket packet;
+    EXPECT_EQ(0, packet.size());
+}
+
+TEST(ChunkPacket, size_from_to)
+{
+    ChunkPacket packet;
+    packet[OsiLayer::Link] = ByteBuffer(8);
+    packet[OsiLayer::Session] = ByteBuffer(19);
+    packet[OsiLayer::Application] = ByteBuffer(5);
+
+    EXPECT_EQ(8, packet.size(OsiLayer::Link, OsiLayer::Link));
+    EXPECT_EQ(0, packet.size(OsiLayer::Network, OsiLayer::Transport));
+    EXPECT_EQ(27, packet.size(OsiLayer::Physical, OsiLayer::Session));
+    EXPECT_EQ(24, packet.size(OsiLayer::Session, OsiLayer::Application));
+}
+
+TEST(ChunkPacket, access)
+{
+    const ByteBuffer data { 3, 8, 7, 5, 6 };
+    ChunkPacket packet;
+    packet[OsiLayer::Transport] = ByteBuffer { data };
+
+    EXPECT_EQ(data.size(), packet.size());
+    EXPECT_EQ(data.size(), packet[OsiLayer::Transport].size());
+
+    ByteBuffer tmp;
+    packet[OsiLayer::Transport].convert(tmp);
+    EXPECT_EQ(data, tmp);
+}
+
+TEST(ChunkPacket, copy)
+{
+    ChunkPacket original;
+    original[OsiLayer::Physical] = ByteBuffer(12);
+    original[OsiLayer::Presentation] = ByteBuffer(34);
+
+    ChunkPacket copy { original };
+    EXPECT_EQ(46, copy.size());
+    EXPECT_EQ(12, copy[OsiLayer::Physical].size());
+    EXPECT_EQ(34, copy[OsiLayer::Presentation].size());
+
+    ChunkPacket tmp;
+    tmp = original;
+    EXPECT_EQ(46, tmp.size());
+}
+
+TEST(ChunkPacket, self_assignment)
+{
+    ChunkPacket data;
+    data[OsiLayer::Physical] = ByteBuffer(20);
+    ASSERT_EQ(20, data.size());
+    data = data;
+    EXPECT_EQ(20, data.size());
+}
+
+TEST(ChunkPacket, extract)
+{
+    std::array<ByteBuffer, 5> buffer;
+    for (unsigned i = 0; i < buffer.size(); ++i) {
+        ByteBuffer tmp;
+        tmp.resize(10, static_cast<ByteBuffer::value_type>(i));
+        buffer[i] = std::move(tmp);
+    }
+
+    ChunkPacket a;
+    a[OsiLayer::Link] = ByteBuffer { buffer[0] };
+    a[OsiLayer::Network] = ByteBuffer { buffer[1] };
+    a[OsiLayer::Transport] = ByteBuffer { buffer[2] };
+    a[OsiLayer::Session] = ByteBuffer { buffer[3] };
+    a[OsiLayer::Application] = ByteBuffer { buffer[4] };
+    EXPECT_EQ(50, a.size());
+
+    ChunkPacket b = a.extract(OsiLayer::Network, OsiLayer::Presentation);
+    EXPECT_EQ(20, a.size());
+    EXPECT_EQ(30, b.size());
+
+    ByteBuffer tmp;
+    a[OsiLayer::Link].convert(tmp);
+    EXPECT_EQ(buffer[0], tmp);
+    a[OsiLayer::Application].convert(tmp);
+    EXPECT_EQ(buffer[4], tmp);
+
+    b[OsiLayer::Network].convert(tmp);
+    EXPECT_EQ(buffer[1], tmp);
+    b[OsiLayer::Transport].convert(tmp);
+    EXPECT_EQ(buffer[2], tmp);
+    b[OsiLayer::Session].convert(tmp);
+    EXPECT_EQ(buffer[3], tmp);
+}
+
+TEST(ChunkPacket, merge)
+{
+    std::array<ByteBuffer, 11> buffer;
+    for (unsigned i = 0; i < buffer.size(); ++i) {
+        ByteBuffer tmp;
+        tmp.resize(10, static_cast<ByteBuffer::value_type>(i));
+        buffer[i] = std::move(tmp);
+    }
+
+    ChunkPacket a;
+    a[OsiLayer::Physical] = ByteBuffer { buffer[0] };
+    a[OsiLayer::Link] = ByteBuffer { buffer[1] };
+    a[OsiLayer::Network] = ByteBuffer { buffer[2] };
+    a[OsiLayer::Transport] = ByteBuffer { buffer[3] };
+    a[OsiLayer::Session] = ByteBuffer { buffer[4] };
+    a[OsiLayer::Application] = ByteBuffer { buffer[5] };
+    ASSERT_EQ(60, a.size());
+
+    ChunkPacket b;
+    b[OsiLayer::Physical] = ByteBuffer { buffer[6] };
+    b[OsiLayer::Link] = ByteBuffer { buffer[7] };
+    b[OsiLayer::Network] = ByteBuffer { buffer[8] };
+    b[OsiLayer::Transport] = ByteBuffer { buffer[9] };
+    b[OsiLayer::Application] = ByteBuffer { buffer[10] };
+    ASSERT_EQ(50, b.size());
+
+    a.merge(b, OsiLayer::Link, OsiLayer::Presentation);
+    EXPECT_EQ(50, a.size());
+
+    ByteBuffer tmp;
+    a[OsiLayer::Physical].convert(tmp);
+    EXPECT_EQ(buffer[0], tmp);
+    a[OsiLayer::Link].convert(tmp);
+    EXPECT_EQ(buffer[7], tmp);
+    a[OsiLayer::Network].convert(tmp);
+    EXPECT_EQ(buffer[8], tmp);
+    a[OsiLayer::Transport].convert(tmp);
+    EXPECT_EQ(buffer[9], tmp);
+    a[OsiLayer::Session].convert(tmp);
+    EXPECT_TRUE(tmp.empty());
+    a[OsiLayer::Presentation].convert(tmp);
+    EXPECT_TRUE(tmp.empty());
+    a[OsiLayer::Application].convert(tmp);
+    EXPECT_EQ(buffer[5], tmp);
+}