Fix invalid scheme errors (#403)

* Version 0.13.6

* Fix broken error messaging when URL scheme is missing, or a non HTTP(S) scheme is used.

* Update CHANGELOG.md

Author: lovelydinosaur

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## Master
+
+- Fix broken error messaging when URL scheme is missing, or a non HTTP(S) scheme is used. (Pull #403)
+
 ## 0.13.6 (June 15th, 2021)
 
 ### Fixed

httpcore/_async/connection_pool.py

@@ -195,19 +195,16 @@ async def handle_async_request(
         stream: AsyncByteStream,
         extensions: dict,
     ) -> Tuple[int, Headers, AsyncByteStream, dict]:
+        if not url[0]:
+            raise UnsupportedProtocol(
+                "Request URL missing either an 'http://' or 'https://' protocol."
+            )
+
         if url[0] not in (b"http", b"https"):
-            scheme = url[0].decode("latin-1")
-            host = url[1].decode("latin-1")
-            if scheme == "":
-                raise UnsupportedProtocol(
-                    f"The request to '://{host}/' is missing either an 'http://' \
-                        or 'https://' protocol."
-                )
-            else:
-                raise UnsupportedProtocol(
-                    f"The request to '{scheme}://{host}' has \
-                        an unsupported protocol {scheme!r}"
-                )
+            protocol = url[0].decode("ascii")
+            raise UnsupportedProtocol(
+                f"Request URL has an unsupported protocol '{protocol}://'."
+            )
 
         if not url[1]:
             raise LocalProtocolError("Missing hostname in URL.")

httpcore/_sync/connection_pool.py

@@ -195,19 +195,16 @@ def handle_request(
         stream: SyncByteStream,
         extensions: dict,
     ) -> Tuple[int, Headers, SyncByteStream, dict]:
+        if not url[0]:
+            raise UnsupportedProtocol(
+                "Request URL missing either an 'http://' or 'https://' protocol."
+            )
+
         if url[0] not in (b"http", b"https"):
-            scheme = url[0].decode("latin-1")
-            host = url[1].decode("latin-1")
-            if scheme == "":
-                raise UnsupportedProtocol(
-                    f"The request to '://{host}/' is missing either an 'http://' \
-                        or 'https://' protocol."
-                )
-            else:
-                raise UnsupportedProtocol(
-                    f"The request to '{scheme}://{host}' has \
-                        an unsupported protocol {scheme!r}"
-                )
+            protocol = url[0].decode("ascii")
+            raise UnsupportedProtocol(
+                f"Request URL has an unsupported protocol '{protocol}://'."
+            )
 
         if not url[1]:
             raise LocalProtocolError("Missing hostname in URL.")