From 6df910a61c19817c9f07c73b85c4ac749dffb10f Mon Sep 17 00:00:00 2001
From: Sean McArthur <sean@seanmonstar.com>
Date: Thu, 25 Apr 2019 18:36:31 -0700
Subject: [PATCH] re-add Error::cause() impl

---
 src/error.rs | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/src/error.rs b/src/error.rs
index b7b355b..11c6ea8 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -322,6 +322,34 @@ impl StdError for Error {
         }
     }
 
+    // Keep this for now, as std::io::Error didn't support source() until 1.35
+    #[allow(deprecated)]
+    fn cause(&self) -> Option<&dyn StdError> {
+        match self.inner.kind {
+            Kind::Http(ref e) => e.cause(),
+            Kind::Hyper(ref e) => e.cause(),
+            Kind::Mime(ref e) => e.cause(),
+            Kind::Url(ref e) => e.cause(),
+            #[cfg(all(feature = "default-tls", feature = "rustls-tls"))]
+            Kind::TlsIncompatible => None,
+            #[cfg(feature = "default-tls")]
+            Kind::NativeTls(ref e) => e.cause(),
+            #[cfg(feature = "rustls-tls")]
+            Kind::Rustls(ref e) => e.cause(),
+            #[cfg(feature = "trust-dns")]
+            Kind::DnsSystemConf(ref e) => e.cause(),
+            Kind::Io(ref e) => e.cause(),
+            Kind::UrlEncoded(ref e) => e.cause(),
+            Kind::Json(ref e) => e.cause(),
+            Kind::UrlBadScheme |
+            Kind::TooManyRedirects |
+            Kind::RedirectLoop |
+            Kind::Status(_) |
+            Kind::UnknownProxyScheme |
+            Kind::Timer => None,
+        }
+    }
+
     fn source(&self) -> Option<&(dyn StdError + 'static)> {
         match self.inner.kind {
             Kind::Http(ref e) => e.source(),