Allows "classic" CONNECT request headers even when the extended connection option has been set.

PiperOrigin-RevId: 450736697

quiche/http2/adapter/header_validator.cc

diff --git a/quiche/http2/adapter/header_validator.cc b/quiche/http2/adapter/header_validator.cc
index 972b0c6..67d543a 100644
--- a/quiche/http2/adapter/header_validator.cc
+++ b/quiche/http2/adapter/header_validator.cc
@@ -96,14 +96,15 @@
       static const std::vector<std::string>* kExtendedConnectHeaders =
           new std::vector<std::string>(
               {":authority", ":method", ":path", ":protocol", ":scheme"});
-      return pseudo_headers == *kExtendedConnectHeaders;
-    } else {
-      // See RFC 7540 Section 8.3.
-      static const std::vector<std::string>* kConnectHeaders =
-          new std::vector<std::string>({":authority", ":method"});
-      return authority.has_value() && !authority.value().empty() &&
-             pseudo_headers == *kConnectHeaders;
+      if (pseudo_headers == *kExtendedConnectHeaders) {
+        return true;
+      }
     }
+    // See RFC 7540 Section 8.3.
+    static const std::vector<std::string>* kConnectHeaders =
+        new std::vector<std::string>({":authority", ":method"});
+    return authority.has_value() && !authority.value().empty() &&
+           pseudo_headers == *kConnectHeaders;
   }
 
   if (path.empty()) {

quiche/http2/adapter/header_validator_test.cc

diff --git a/quiche/http2/adapter/header_validator_test.cc b/quiche/http2/adapter/header_validator_test.cc
index fc3e207..6e446f2 100644
--- a/quiche/http2/adapter/header_validator_test.cc
+++ b/quiche/http2/adapter/header_validator_test.cc
@@ -303,6 +303,15 @@
   EXPECT_EQ(HeaderValidator::HEADER_OK,
             v.ValidateSingleHeader(":method", "CONNECT"));
   EXPECT_TRUE(v.FinishHeaderBlock(HeaderType::REQUEST));
+
+  v.SetAllowExtendedConnect();
+  // "Classic" CONNECT headers should still be accepted.
+  v.StartHeaderBlock();
+  EXPECT_EQ(HeaderValidator::HEADER_OK,
+            v.ValidateSingleHeader(":authority", "athena.dialup.mit.edu:23"));
+  EXPECT_EQ(HeaderValidator::HEADER_OK,
+            v.ValidateSingleHeader(":method", "CONNECT"));
+  EXPECT_TRUE(v.FinishHeaderBlock(HeaderType::REQUEST));
 }
 
 TEST(HeaderValidatorTest, WebsocketPseudoHeaders) {