fix ReadAtLeastAsync (#37130) (#37151)

wfurt · web-flow · commit d06ce9d2116c · 2019-04-24T14:36:35.000-07:00
diff --git a/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs b/src/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs
@@ -1483,7 +1483,7 @@ internal static async ValueTask<int> ReadAtLeastAsync(Stream stream, Memory<byte
             int totalBytesRead = 0;
             while (totalBytesRead < minReadBytes)
             {
-                int bytesRead = await stream.ReadAsync(buffer).ConfigureAwait(false);
+                int bytesRead = await stream.ReadAsync(buffer.Slice(totalBytesRead)).ConfigureAwait(false);
                 if (bytesRead == 0)
                 {
                     throw new IOException(SR.net_http_invalid_response);

Original file line number	Diff line number	Diff line change
`@@ -1483,7 +1483,7 @@ internal static async ValueTask<int> ReadAtLeastAsync(Stream stream, Memory<byte`
`1483`	`1483`	`int totalBytesRead = 0;`
`1484`	`1484`	`while (totalBytesRead < minReadBytes)`
`1485`	`1485`	`{`
`1486`		`- int bytesRead = await stream.ReadAsync(buffer).ConfigureAwait(false);`
	`1486`	`+ int bytesRead = await stream.ReadAsync(buffer.Slice(totalBytesRead)).ConfigureAwait(false);`
`1487`	`1487`	`if (bytesRead == 0)`
`1488`	`1488`	`{`
`1489`	`1489`	`throw new IOException(SR.net_http_invalid_response);`