fuzz: Disable jetscii for more stability

Author: untitaker

fuzz/Cargo.lock

@@ -9,11 +9,11 @@ cargo-fuzz = true
 [dependencies]
 libfuzzer-sys = "0.4"
 afl = { version = "0.17.0", optional = true }
-html5gum = { path = "../" }
+html5gum = { path = "../", default-features = false }
 pretty_assertions = "1.0.0"
 
 # thirdparty crates to fuzz against
-html5gum_old = { version = "=0.6.1", package = "html5gum" }
+html5gum_old = { version = "=0.6.1", package = "html5gum", default-features = false }
 html5ever = "0.36.1"
 swc_common = "18.0"
 swc_html_parser = "18.0"

fuzz/Cargo.toml

@@ -89,3 +89,9 @@ other's testcases to some degree, as `cargo-fuzz` is wired to read from both
 `in/` and `out/`, and AFL is wired to read from `in/` and manage its queue in
 `out/`. See [AFL compatibility in libfuzzer
 docs](https://llvm.org/docs/LibFuzzer.html#afl-compatibility).
+
+## Stability
+
+The `jetscii` crate is causing instability in AFL coverage instrumentation and
+has therefore been disabled in html5gum. The `memchr` crate probably has
+stability issues too, if third-party parsers use it.