From a9f8ea0a1e8ba1206f8c28d96b924606847b85a9 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sun, 21 Jun 2020 17:22:07 -0700
Subject: [PATCH] Simplify search for packed repr attr

---
 serde_derive/Cargo.toml            |  2 +-
 serde_derive/src/internals/attr.rs | 17 +++++------------
 serde_derive_internals/Cargo.toml  |  2 +-
 3 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/serde_derive/Cargo.toml b/serde_derive/Cargo.toml
index de03621b..5921d9dc 100644
--- a/serde_derive/Cargo.toml
+++ b/serde_derive/Cargo.toml
@@ -22,7 +22,7 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "1.0", features = ["visit"] }
+syn = { version = "1.0.33", features = ["visit"] }
 
 [dev-dependencies]
 serde = { version = "1.0", path = "../serde" }
diff --git a/serde_derive/src/internals/attr.rs b/serde_derive/src/internals/attr.rs
index d32c1f52..e6f72dfe 100644
--- a/serde_derive/src/internals/attr.rs
+++ b/serde_derive/src/internals/attr.rs
@@ -597,19 +597,12 @@ impl Container {
         for attr in &item.attrs {
             if attr.path.is_ident("repr") {
                 let _ = attr.parse_args_with(|input: ParseStream| {
-                    input.step(|cursor| {
-                        let mut rest = *cursor;
-                        while let Some((tt, next)) = rest.token_tree() {
-                            match &tt {
-                                TokenTree::Ident(ident) if ident == "packed" => {
-                                    is_packed |= true;
-                                    return Ok(((), next));
-                                }
-                                _ => rest = next,
-                            }
+                    while let Some(token) = input.parse()? {
+                        if let TokenTree::Ident(ident) = token {
+                            is_packed |= ident == "packed";
                         }
-                        Err(cursor.error("no `packed` was found in the reprs"))
-                    })
+                    }
+                    Ok(())
                 });
             }
         }
diff --git a/serde_derive_internals/Cargo.toml b/serde_derive_internals/Cargo.toml
index 164f2751..64ee1c62 100644
--- a/serde_derive_internals/Cargo.toml
+++ b/serde_derive_internals/Cargo.toml
@@ -16,7 +16,7 @@ path = "lib.rs"
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "1.0", default-features = false, features = ["derive", "parsing", "printing", "clone-impls"] }
+syn = { version = "1.0.33", default-features = false, features = ["derive", "parsing", "printing", "clone-impls"] }
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]