Remove unnecessary check

aspnet · Jan 10, 2017 · 4436860 · 4436860
1 parent 3297a9a
commit 4436860
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/FrameHeaders.cs b/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/FrameHeaders.cs
@@ -253,9 +253,9 @@ public static unsafe void ValidateHeaderCharacters(string headerCharacters)
                     }
 
                     // Non-vector testing:
-                    // Flag > 0x007f => Use value directly, already flagged
                     // Flag 0x7f     => Add 0x0001 to each char so DEL (0x7f) will set a high bit
                     // Flag < 0x20   => Sub 0x0020 from each char so high bit will be set in previous char bit
+                    // Flag > 0x007f => All but highest bit picked up by 0x7f flagging, highest bit picked up by < 0x20 flagging
                     // Bitwise | or the above three together
                     // Bitwise & and each char with 0xff80; result should be 0 if all tests pass
                     if (offset + sizeof(ulong) <= length)
@@ -264,7 +264,7 @@ public static unsafe void ValidateHeaderCharacters(string headerCharacters)
                         {
                             var stringUlong = (ulong*)(pHeader + offset);
                             offset += sizeof(ulong);
-                            if (((*stringUlong | (*stringUlong + 0x0001000100010001UL) | (*stringUlong - 0x0020002000200020UL)) & 0xff80ff80ff80ff80UL) != 0)
+                            if ((((*stringUlong + 0x0001000100010001UL) | (*stringUlong - 0x0020002000200020UL)) & 0xff80ff80ff80ff80UL) != 0)
                             {
                                 ThrowInvalidHeaderCharacter(pHeader + offset, sizeof(ulong));
                             }
@@ -274,7 +274,7 @@ public static unsafe void ValidateHeaderCharacters(string headerCharacters)
                     {
                         var stringUint = (uint*)(pHeader + offset);
                         offset += sizeof(uint);
-                        if (((*stringUint | (*stringUint + 0x00010001u) | (*stringUint - 0x00200020u)) & 0xff80ff80u) != 0)
+                        if ((((*stringUint + 0x00010001u) | (*stringUint - 0x00200020u)) & 0xff80ff80u) != 0)
                         {
                             ThrowInvalidHeaderCharacter(pHeader + offset, sizeof(uint));
                         }
@@ -283,7 +283,7 @@ public static unsafe void ValidateHeaderCharacters(string headerCharacters)
                     {
                         var stringUshort = (ushort*)(pHeader + offset);
                         offset += sizeof(ushort);
-                        if (((*stringUshort | (*stringUshort + 0x0001u) | (*stringUshort - 0x0020u)) & 0xff80u) != 0)
+                        if ((((*stringUshort + 0x0001u) | (*stringUshort - 0x0020u)) & 0xff80u) != 0)
                         {
                             ThrowInvalidHeaderCharacter(pHeader + offset, sizeof(ushort));
                         }