Add fuzz test for ZDICT_trainFromBuffer_legacy

Author: michielp1807

.github/workflows/checks.yaml

@@ -199,6 +199,7 @@ jobs:
           cargo fuzz run dictionary_round_trip -- -max_total_time=10
           cargo fuzz run dictionary_train -- -dict=./fuzz/dictionaries/dictionary_train.txt -max_total_time=60
           cargo fuzz run dictionary_train_fast -- -dict=./fuzz/dictionaries/dictionary_train.txt -max_total_time=60
+          cargo fuzz run dictionary_train_legacy -- -dict=./fuzz/dictionaries/dictionary_train.txt -max_total_time=60
         env:
           RUSTFLAGS: "-Awarnings"
 

fuzz/Cargo.toml

@@ -49,3 +49,10 @@ path = "fuzz_targets/dictionary_train_fast.rs"
 test = false
 doc = false
 bench = false
+
+[[bin]]
+name = "dictionary_train_legacy"
+path = "fuzz_targets/dictionary_train_legacy.rs"
+test = false
+doc = false
+bench = false

fuzz/fuzz_targets/dictionary_train_legacy.rs

@@ -0,0 +1,24 @@
+#![no_main]
+
+use c2rust_out_fuzz::{assert_eq_rs_c, ArbitrarySamples};
+use libfuzzer_sys::fuzz_target;
+
+// COVER dictionary builder tests
+fuzz_target!(|samples: ArbitrarySamples| {
+    // train
+    assert_eq_rs_c!({
+        let params = libzstd_rs_sys::ZDICT_legacy_params_t::default();
+
+        let mut dict = vec![0u8; samples.dict_size];
+        let dict_size = ZDICT_trainFromBuffer_legacy(
+            dict.as_mut_ptr().cast(),
+            samples.dict_size,
+            samples.samples.as_ptr().cast(),
+            samples.sample_sizes.as_ptr(),
+            samples.nb_samples as u32,
+            std::mem::transmute(params),
+        );
+
+        (dict_size, dict)
+    });
+});