From 538b91fc6e24168c878db4341bd1e118a08851ae Mon Sep 17 00:00:00 2001
From: Jesse Wilson <jwilson@squareup.com>
Date: Tue, 23 Apr 2024 20:13:18 -0400
Subject: [PATCH] Remove renumbering indirection in settings frames

This makes the code difficult to understand.
---
 .../src/main/kotlin/okhttp3/internal/http2/Http2Reader.kt | 6 +++---
 .../src/main/kotlin/okhttp3/internal/http2/Http2Writer.kt | 8 +-------
 okhttp/src/main/kotlin/okhttp3/internal/http2/Settings.kt | 8 ++++----
 3 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/okhttp/src/main/kotlin/okhttp3/internal/http2/Http2Reader.kt b/okhttp/src/main/kotlin/okhttp3/internal/http2/Http2Reader.kt
index 38e7c685ba0a..cc8a4cc11486 100644
--- a/okhttp/src/main/kotlin/okhttp3/internal/http2/Http2Reader.kt
+++ b/okhttp/src/main/kotlin/okhttp3/internal/http2/Http2Reader.kt
@@ -261,7 +261,7 @@ class Http2Reader(
     if (length % 6 != 0) throw IOException("TYPE_SETTINGS length % 6 != 0: $length")
     val settings = Settings()
     for (i in 0 until length step 6) {
-      var id = source.readShort() and 0xffff
+      val id = source.readShort() and 0xffff
       val value = source.readInt()
 
       when (id) {
@@ -277,11 +277,11 @@ class Http2Reader(
         }
 
         // SETTINGS_MAX_CONCURRENT_STREAMS
-        3 -> id = 4 // Renumbered in draft 10.
+        3 -> {
+        }
 
         // SETTINGS_INITIAL_WINDOW_SIZE
         4 -> {
-          id = 7 // Renumbered in draft 10.
           if (value < 0) {
             throw IOException("PROTOCOL_ERROR SETTINGS_INITIAL_WINDOW_SIZE > 2^31 - 1")
           }
diff --git a/okhttp/src/main/kotlin/okhttp3/internal/http2/Http2Writer.kt b/okhttp/src/main/kotlin/okhttp3/internal/http2/Http2Writer.kt
index 6c63ef263300..ca8de63c9598 100644
--- a/okhttp/src/main/kotlin/okhttp3/internal/http2/Http2Writer.kt
+++ b/okhttp/src/main/kotlin/okhttp3/internal/http2/Http2Writer.kt
@@ -209,13 +209,7 @@ class Http2Writer(
       )
       for (i in 0 until Settings.COUNT) {
         if (!settings.isSet(i)) continue
-        val id =
-          when (i) {
-            4 -> 3 // SETTINGS_MAX_CONCURRENT_STREAMS renumbered.
-            7 -> 4 // SETTINGS_INITIAL_WINDOW_SIZE renumbered.
-            else -> i
-          }
-        sink.writeShort(id)
+        sink.writeShort(i)
         sink.writeInt(settings[i])
       }
       sink.flush()
diff --git a/okhttp/src/main/kotlin/okhttp3/internal/http2/Settings.kt b/okhttp/src/main/kotlin/okhttp3/internal/http2/Settings.kt
index ef704cdfde5d..a52bd3321037 100644
--- a/okhttp/src/main/kotlin/okhttp3/internal/http2/Settings.kt
+++ b/okhttp/src/main/kotlin/okhttp3/internal/http2/Settings.kt
@@ -116,7 +116,10 @@ class Settings {
     const val ENABLE_PUSH = 2
 
     /** Sender's maximum number of concurrent streams. */
-    const val MAX_CONCURRENT_STREAMS = 4
+    const val MAX_CONCURRENT_STREAMS = 3
+
+    /** Window size in bytes. */
+    const val INITIAL_WINDOW_SIZE = 4
 
     /** HTTP/2: Size in bytes of the largest frame payload the sender will accept. */
     const val MAX_FRAME_SIZE = 5
@@ -124,9 +127,6 @@ class Settings {
     /** HTTP/2: Advisory only. Size in bytes of the largest header list the sender will accept. */
     const val MAX_HEADER_LIST_SIZE = 6
 
-    /** Window size in bytes. */
-    const val INITIAL_WINDOW_SIZE = 7
-
     /** Total number of settings. */
     const val COUNT = 10
   }