Remove unsafe

src/lib.rs

@@ -16,6 +16,7 @@
 //! [Cloudflare Workers]: https://www.cloudflare.com/en-gb/products/cloudflare-workers/
 //! [`HtmlRewriter`]: struct.HtmlRewriter.html
 //! [`rewrite_str`]: fn.rewrite_str.html
+#![forbid(unsafe_code)]
 #![allow(clippy::default_trait_access)]
 #![allow(clippy::module_name_repetitions)]
 #![allow(clippy::redundant_pub_crate)]

src/rewritable_units/mutations.rs

@@ -150,9 +150,6 @@ pub trait StreamingHandler: Send {
     // Safety: due to lack of Sync, this trait must not have `&self` methods
 }
 
-/// Avoid requring `StreamingHandler` to be `Sync`.
-/// It only has a method taking exclusive ownership, so there's no sharing possible.
-unsafe impl Sync for StringChunk {}
 impl RefUnwindSafe for StringChunk {}
 impl UnwindSafe for StringChunk {}
 

src/rewritable_units/text_encoder.rs

@@ -306,9 +306,8 @@ impl IncompleteUtf8Resync {
                         .ok_or(Utf8Error)?
                         .copy_from_slice(invalid);
                     self.char_len = invalid.len() as _;
-                    // valid_up_to promises it is valid
-                    debug_assert!(std::str::from_utf8(valid).is_ok());
-                    let valid = unsafe { std::str::from_utf8_unchecked(valid) };
+                    // valid_up_to promises it is always valid
+                    let valid = std::str::from_utf8(valid).map_err(|_| Utf8Error)?;
                     Ok((valid, b""))
                 }
             }