address PR feedback

3 files changed, 30 insertions, 35 deletions

diff --git a/src/System.Net.Http/src/System/Net/Http/ByteArrayHelpers.cs b/src/System.Net.Http/src/System/Net/Http/ByteArrayHelpers.cs
index 23f133eaaa..cd28c40b9a 100644
--- a/src/System.Net.Http/src/System/Net/Http/ByteArrayHelpers.cs
+++ b/src/System.Net.Http/src/System/Net/Http/ByteArrayHelpers.cs
@@ -41,18 +41,13 @@ namespace System
             return true;
         }
 
-        internal static string GetStringFromByteSpan(ReadOnlySpan<byte> bytes)
+        internal static unsafe string GetStringFromByteSpan(ReadOnlySpan<byte> bytes)
         {
-            string s;
-            unsafe
+            // TODO: Use new Span-based Encoding overload when available
+            fixed (byte* p = &bytes.DangerousGetPinnableReference())
             {
-                fixed (byte* p = &bytes.DangerousGetPinnableReference())
-                {
-                    s = Encoding.ASCII.GetString(p, bytes.Length);
-                }
+                return Encoding.ASCII.GetString(p, bytes.Length);
             }
-
-            return s;
         }
     }
 }
diff --git a/src/System.Net.Http/src/System/Net/Http/Headers/HeaderDescriptor.cs b/src/System.Net.Http/src/System/Net/Http/Headers/HeaderDescriptor.cs
index 4b4ca304ab..3737e44709 100644
--- a/src/System.Net.Http/src/System/Net/Http/Headers/HeaderDescriptor.cs
+++ b/src/System.Net.Http/src/System/Net/Http/Headers/HeaderDescriptor.cs
@@ -100,9 +100,9 @@ namespace System.Net.Http.Headers
             }
 
             // If it's a known header value, use the known value instead of allocating a new string.
-            string[] knownValues = _knownHeader?.KnownValues;
-            if (knownValues != null)
+            if (_knownHeader != null && _knownHeader.KnownValues != null)
             {
+                string[] knownValues = _knownHeader.KnownValues;
                 for (int i = 0; i < knownValues.Length; i++)
                 {
                     if (ByteArrayHelpers.EqualsOrdinalAsciiIgnoreCase(knownValues[i], headerValue))
diff --git a/src/System.Net.Http/src/System/Net/Http/Headers/KnownHeaders.cs b/src/System.Net.Http/src/System/Net/Http/Headers/KnownHeaders.cs
index bdad477aec..ac209a1fba 100644
--- a/src/System.Net.Http/src/System/Net/Http/Headers/KnownHeaders.cs
+++ b/src/System.Net.Http/src/System/Net/Http/Headers/KnownHeaders.cs
@@ -98,7 +98,7 @@ namespace System.Net.Http.Headers
         private interface IHeaderNameAccessor
         {
             int Length { get; }
-            char CharAt(int index);
+            char this[int index] { get; }
         }
 
         private struct StringAccessor : IHeaderNameAccessor
@@ -111,14 +111,14 @@ namespace System.Net.Http.Headers
             }
 
             public int Length => _string.Length;
-            public char CharAt(int index) => _string[index];
+            public char this[int index] => _string[index];
         }
 
         // Can't use Span here as it's unsupported.
         private unsafe struct BytePtrAccessor : IHeaderNameAccessor
         {
-            private byte* _p;
-            private int _length;
+            private readonly byte* _p;
+            private readonly int _length;
 
             public BytePtrAccessor(byte* p, int length)
             {
@@ -127,7 +127,7 @@ namespace System.Net.Http.Headers
             }
 
             public int Length => _length;
-            public char CharAt(int index) => (char)_p[index];
+            public char this[int index] => (char)_p[index];
         }
 
         // Find possible known header match via lookup on length and a distinguishing char for that length.
@@ -144,7 +144,7 @@ namespace System.Net.Http.Headers
                     return TE; // TE
 
                 case 3:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'A': case 'a': return Age; // [A]ge
                         case 'P': case 'p': return P3P; // [P]3P
@@ -154,7 +154,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 4:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'D': case 'd': return Date; // [D]ate
                         case 'E': case 'e': return ETag; // [E]Tag
@@ -166,7 +166,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 5:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'A': case 'a': return Allow; // [A]llow
                         case 'R': case 'r': return Range; // [R]ange
@@ -174,7 +174,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 6:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'A': case 'a': return Accept; // [A]ccept
                         case 'C': case 'c': return Cookie; // [C]ookie
@@ -186,7 +186,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 7:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'A': case 'a': return AltSvc;  // [A]lt-Svc
                         case 'C': case 'c': return Cookie2; // [C]ookie2
@@ -199,7 +199,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 8:
-                    switch (key.CharAt(3))
+                    switch (key[3])
                     {
                         case 'M': case 'm': return IfMatch;  // If-[M]atch
                         case 'R': case 'r': return IfRange;  // If-[R]ange
@@ -208,7 +208,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 10:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'C': case 'c': return Connection; // [C]onnection
                         case 'K': case 'k': return KeepAlive;  // [K]eep-Alive
@@ -218,7 +218,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 11:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'C': case 'c': return ContentMD5; // [C]ontent-MD5
                         case 'R': case 'r': return RetryAfter; // [R]etry-After
@@ -227,7 +227,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 12:
-                    switch (key.CharAt(2))
+                    switch (key[2])
                     {
                         case 'C': case 'c': return AcceptPatch; // Ac[c]ept-Patch
                         case 'N': case 'n': return ContentType; // Co[n]tent-Type
@@ -239,7 +239,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 13:
-                    switch (key.CharAt(6))
+                    switch (key[6])
                     {
                         case '-': return AcceptRanges;            // Accept[-]Ranges
                         case 'I': case 'i': return Authorization; // Author[i]zation
@@ -251,7 +251,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 14:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'A': case 'a': return AcceptCharset; // [A]ccept-Charset
                         case 'C': case 'c': return ContentLength; // [C]ontent-Length
@@ -259,7 +259,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 15:
-                    switch (key.CharAt(7))
+                    switch (key[7])
                     {
                         case '-': return XFrameOptions;  // X-Frame[-]Options
                         case 'M': case 'm': return XUACompatible;  // X-UA-Co[m]patible
@@ -270,7 +270,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 16:
-                    switch (key.CharAt(11))
+                    switch (key[11])
                     {
                         case 'O': case 'o': return ContentEncoding; // Content-Enc[o]ding
                         case 'G': case 'g': return ContentLanguage; // Content-Lan[g]uage
@@ -282,7 +282,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 17:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'I': case 'i': return IfModifiedSince;  // [I]f-Modified-Since
                         case 'S': case 's': return SecWebSocketKey;  // [S]ec-WebSocket-Key
@@ -291,7 +291,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 18:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'P': case 'p': return ProxyAuthenticate; // [P]roxy-Authenticate
                         case 'X': case 'x': return XContentDuration;  // [X]-Content-Duration
@@ -299,7 +299,7 @@ namespace System.Net.Http.Headers
                     break;
 
                 case 19:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'C': case 'c': return ContentDisposition; // [C]ontent-Disposition
                         case 'I': case 'i': return IfUnmodifiedSince;  // [I]f-Unmodified-Since
@@ -314,7 +314,7 @@ namespace System.Net.Http.Headers
                     return SecWebSocketVersion; // Sec-WebSocket-Version
 
                 case 22:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'A': case 'a': return AccessControlMaxAge;  // [A]ccess-Control-Max-Age
                         case 'S': case 's': return SecWebSocketProtocol; // [S]ec-WebSocket-Protocol
@@ -329,7 +329,7 @@ namespace System.Net.Http.Headers
                     return SecWebSocketExtensions; // Sec-WebSocket-Extensions
 
                 case 25:
-                    switch (key.CharAt(0))
+                    switch (key[0])
                     {
                         case 'S': case 's': return StrictTransportSecurity; // [S]trict-Transport-Security
                         case 'U': case 'u': return UpgradeInsecureRequests; // [U]pgrade-Insecure-Requests
@@ -340,7 +340,7 @@ namespace System.Net.Http.Headers
                     return AccessControlAllowOrigin; // Access-Control-Allow-Origin
 
                 case 28:
-                    switch (key.CharAt(21))
+                    switch (key[21])
                     {
                         case 'H': case 'h': return AccessControlAllowHeaders; // Access-Control-Allow-[H]eaders
                         case 'M': case 'm': return AccessControlAllowMethods; // Access-Control-Allow-[M]ethods