From fa12fd3c82a50e33e49f68e1cf8ae4d444b8d035 Mon Sep 17 00:00:00 2001
From: Deepak Lewis <192128+tailrecur@users.noreply.github.com>
Date: Fri, 19 Feb 2021 14:58:35 +0100
Subject: [PATCH] Disable expect header usage using a request extension

---
 src/client.rs     | 5 +++++
 src/config/mod.rs | 9 +++++++++
 2 files changed, 14 insertions(+)

diff --git a/src/client.rs b/src/client.rs
index 704f97cf..fa2d7f3e 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -1174,6 +1174,11 @@ impl HttpClient {
             headers.append(&header_to_curl_string(name, value, title_case))?;
         }
 
+        request
+            .extensions()
+            .get::<DisableExpectHeader>()
+            .map(|_| headers.append("Expect:"));
+
         easy.http_headers(headers)?;
 
         Ok((easy, future))
diff --git a/src/config/mod.rs b/src/config/mod.rs
index 1364356c..69efead2 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -566,6 +566,11 @@ pub trait Configurable: internal::ConfigurableBase {
         self.configure(TitleCaseHeaders(enable))
     }
 
+    /// Disable using `Expect` header to test request validity
+    fn disable_expect_header(self) -> Self {
+        self.configure(DisableExpectHeader(true))
+    }
+
     /// Enable or disable comprehensive per-request metrics collection.
     ///
     /// When enabled, detailed timing metrics will be tracked while a request is
@@ -919,3 +924,7 @@ impl SetOpt for IpVersion {
 /// Send header names as title case instead of lowercase.
 #[derive(Clone, Debug)]
 pub(crate) struct TitleCaseHeaders(pub(crate) bool);
+
+/// Disable Expect Header usage
+#[derive(Clone, Debug)]
+pub(crate) struct DisableExpectHeader(pub(crate) bool);