fix incorrect count calculation for host->guest stream writes (#91)

This also updates the `wit-bindgen` dep to pull in an alignment fix.

Fixes #85

Signed-off-by: Joel Dice <joel.dice@fermyon.com>

Author: dicej

Cargo.lock

@@ -301,9 +301,9 @@ io-lifetimes = { version = "2.0.3", default-features = false }
 io-extras = "0.18.1"
 rustix = "0.38.43"
 # TODO: switch back to release:
-wit-bindgen = { git = "https://github.com/bytecodealliance/wit-bindgen", rev = "3df706cf", default-features = false }
-wit-bindgen-rt = { git = "https://github.com/bytecodealliance/wit-bindgen", rev = "3df706cf", default-features = false }
-wit-bindgen-rust-macro = { git = "https://github.com/bytecodealliance/wit-bindgen", rev = "3df706cf", default-features = false }
+wit-bindgen = { git = "https://github.com/bytecodealliance/wit-bindgen", rev = "ec56282b", default-features = false }
+wit-bindgen-rt = { git = "https://github.com/bytecodealliance/wit-bindgen", rev = "ec56282b", default-features = false }
+wit-bindgen-rust-macro = { git = "https://github.com/bytecodealliance/wit-bindgen", rev = "ec56282b", default-features = false }
 
 # wasm-tools family:
 # TODO: switch back to release:

Cargo.toml

@@ -143,7 +143,7 @@ fn accept<T: func::Lower + Send + Sync + 'static, B: Buffer<T>, U>(
                     .and_then(|b| b.get_mut(..T::SIZE32 * count))
                     .ok_or_else(|| anyhow::anyhow!("read pointer out of bounds of memory"))?;
 
-                let count = values.len().min(usize::try_from(count).unwrap());
+                let count = (values.len() - offset).min(usize::try_from(count).unwrap());
 
                 if let Some(ty) = payload(ty, types) {
                     T::store_list(lower, ty, address, &values[offset..][..count])?;