Add gix_ref::packed::Buffer fuzzer

Author: nathaniel-brough

gix-ref/fuzz/Cargo.toml

@@ -34,3 +34,9 @@ name = "fuzz_log"
 path = "fuzz_targets/fuzz_log.rs"
 test = false
 doc = false
+
+[[bin]]
+name = "fuzz_packed_buffer"
+path = "fuzz_targets/fuzz_packed_buffer.rs"
+test = false
+doc = false

gix-ref/fuzz/fuzz_targets/fuzz_packed_buffer.rs

@@ -0,0 +1,31 @@
+#![no_main]
+
+use anyhow::Result;
+use arbitrary::Arbitrary;
+use bstr::BStr;
+use gix_ref::{packed::Buffer, FullNameRef};
+use libfuzzer_sys::fuzz_target;
+use std::hint::black_box;
+
+#[derive(Debug, Arbitrary)]
+struct Ctx<'a> {
+    packed_file_contents: &'a [u8],
+    name: &'a [u8],
+}
+
+fn fuzz(ctx: Ctx) -> Result<()> {
+    let buffer = Buffer::from_bytes(ctx.packed_file_contents)?;
+    _ = black_box(buffer.iter()?.count());
+
+    let full_name_ref: &FullNameRef = BStr::new(ctx.name).try_into()?;
+    let name = full_name_ref.as_partial_name();
+
+    _ = black_box(buffer.try_find(name));
+    _ = black_box(buffer.find(name));
+
+    Ok(())
+}
+
+fuzz_target!(|ctx: Ctx| {
+    _ = black_box(fuzz(ctx));
+});