Squashed 'external/toxcore/c-toxcore/' changes from 6d634674a9..73d9b845a3

73d9b845a3 cleanup: Remove old type-ordered event getters.
b0840cc02d feat: add ngc events
7df9a51349 refactor: Make event dispatch ordered by receive time.
bcb6592af5 test: Add C++ classes wrapping system interfaces.
4cea4f9ca4 fix: Make all the fuzzers work again, and add a test for protodump.
c4e209ea1d refactor: Factor out malloc+memcpy into memdup.
87bcc4322d fix: Remove fatal error for non-erroneous case
REVERT: 6d634674a9 cleanup: Remove old type-ordered event getters.
REVERT: d1d48d1dfc feat: add ngc events
REVERT: 994ffecc6b refactor: Make event dispatch ordered by receive time.

git-subtree-dir: external/toxcore/c-toxcore
git-subtree-split: 73d9b845a310c3f56d2d6d77ed56b93d84256d6e

testing/fuzzing/toxsave_fuzz_test.cc

@@ -0,0 +1,52 @@
+#include <cassert>
+#include <cstdint>
+#include <vector>
+
+#include "../../toxcore/tox.h"
+#include "../../toxcore/tox_private.h"
+#include "fuzz_support.h"
+
+namespace {
+
+void TestSaveDataLoading(Fuzz_Data &input)
+{
+    Tox_Err_Options_New error_options;
+
+    struct Tox_Options *tox_options = tox_options_new(&error_options);
+
+    assert(tox_options != nullptr);
+    assert(error_options == TOX_ERR_OPTIONS_NEW_OK);
+
+    const size_t savedata_size = input.size();
+    CONSUME_OR_RETURN(const uint8_t *savedata, input, savedata_size);
+
+    Null_System sys;
+    tox_options_set_operating_system(tox_options, sys.sys.get());
+
+    // pass test data to Tox
+    tox_options_set_savedata_data(tox_options, savedata, savedata_size);
+    tox_options_set_savedata_type(tox_options, TOX_SAVEDATA_TYPE_TOX_SAVE);
+
+    Tox *tox = tox_new(tox_options, nullptr);
+    tox_options_free(tox_options);
+    if (tox == nullptr) {
+        // Tox save was invalid, we're finished here
+        return;
+    }
+
+    // verify that the file can be saved again
+    std::vector<uint8_t> new_savedata(tox_get_savedata_size(tox));
+    tox_get_savedata(tox, new_savedata.data());
+
+    tox_kill(tox);
+}
+
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+    Fuzz_Data input{data, size};
+    TestSaveDataLoading(input);
+    return 0;  // Non-zero return values are reserved for future use.
+}