From b233dbc2d2bcc79c9fc574dd5968269df680b073 Mon Sep 17 00:00:00 2001
From: Yan Chen <48968912+chenyan-dfinity@users.noreply.github.com>
Date: Tue, 17 Oct 2023 11:15:40 -0700
Subject: [PATCH] fix error msg for empty type (#478)

* fix error msg for empty type

* fix
---
 Cargo.lock                     | 2 +-
 rust/candid/Cargo.toml         | 2 +-
 rust/candid/src/de.rs          | 6 +++++-
 rust/candid/src/types/value.rs | 3 +--
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index d0334fe3..6ed7a8b7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -257,7 +257,7 @@ checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
 
 [[package]]
 name = "candid"
-version = "0.9.9"
+version = "0.9.10"
 dependencies = [
  "anyhow",
  "arbitrary",
diff --git a/rust/candid/Cargo.toml b/rust/candid/Cargo.toml
index cd1aa777..5351fcbf 100644
--- a/rust/candid/Cargo.toml
+++ b/rust/candid/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "candid"
-version = "0.9.9"
+version = "0.9.10"
 edition = "2021"
 authors = ["DFINITY Team"]
 description = "Candid is an interface description language (IDL) for interacting with canisters running on the Internet Computer."
diff --git a/rust/candid/src/de.rs b/rust/candid/src/de.rs
index 3e8404fe..036440c6 100644
--- a/rust/candid/src/de.rs
+++ b/rust/candid/src/de.rs
@@ -423,7 +423,11 @@ impl<'de> Deserializer<'de> {
     where
         V: Visitor<'de>,
     {
-        Err(Error::subtype("Cannot decode empty type"))
+        Err(if *self.wire_type == TypeInner::Empty {
+            Error::msg("Cannot decode empty type")
+        } else {
+            Error::subtype("Cannot decode empty type")
+        })
     }
     fn deserialize_future<'a, V>(&'a mut self, visitor: V) -> Result<V::Value>
     where
diff --git a/rust/candid/src/types/value.rs b/rust/candid/src/types/value.rs
index 89ac3cf5..a2676218 100644
--- a/rust/candid/src/types/value.rs
+++ b/rust/candid/src/types/value.rs
@@ -451,8 +451,7 @@ impl<'de> Visitor<'de> for IDLValueVisitor {
             5u8 => {
                 use std::io::Read;
                 let len = leb128::read::unsigned(&mut bytes).map_err(E::custom)? as usize;
-                let mut buf = Vec::new();
-                buf.resize(len, 0);
+                let mut buf = vec![0; len];
                 bytes.read_exact(&mut buf).map_err(E::custom)?;
                 let meth = String::from_utf8(buf).map_err(E::custom)?;
                 let id = crate::Principal::try_from(bytes).map_err(E::custom)?;