Revert D116669664

Summary:
This diff reverts D116669664
(The context such as a Sandcastle job, Task, SEV, etc. was not provided.)

Depends on D116669664

Differential Revision: D116857476

fbshipit-source-id: 0a259d48a9e2ad1931bf4eabb4833b7ab76978bb

Author: generatedunixname89002005232357

third-party/folly/src/folly/io/IOBuf.cpp

@@ -860,11 +860,7 @@ IOBuf IOBuf::cloneCoalescedAsValueWithHeadroomTailroom(
 
   // Coalesce into newBuf
   const std::size_t newLength = computeChainDataLength();
-  std::size_t newCapacity = 0;
-  if (!checked_add(&newCapacity, newLength, newHeadroom, newTailroom) ||
-      newCapacity > kMaxIOBufSize) {
-    throw_exception<std::bad_alloc>();
-  }
+  const std::size_t newCapacity = newLength + newHeadroom + newTailroom;
   IOBuf newBuf{CREATE, newCapacity};
   newBuf.advance(newHeadroom);
 

third-party/folly/src/folly/io/test/IOBufTest.cpp

@@ -1576,22 +1576,6 @@ TEST(IOBuf, CoalesceEmptyBuffers) {
   EXPECT_TRUE(ByteRange(StringPiece("hello")) == br);
 }
 
-// cloneCoalescedAsValueWithHeadroomTailroom (and the unique_ptr wrapper that
-// forwards to it) must throw std::bad_alloc when the coalesced capacity
-// overflows size_t rather than wrapping around to an undersized buffer.
-TEST(IOBuf, CloneCoalescedCapacityOverflow) {
-  auto head = fromStr("hello");
-  head->insertAfterThisOne(fromStr("world"));
-  ASSERT_TRUE(head->isChained());
-
-  constexpr auto kMax = std::numeric_limits<std::size_t>::max();
-  EXPECT_THROW(
-      head->cloneCoalescedWithHeadroomTailroom(kMax, kMax), std::bad_alloc);
-  EXPECT_THROW(
-      head->cloneCoalescedAsValueWithHeadroomTailroom(kMax, kMax),
-      std::bad_alloc);
-}
-
 TEST(IOBuf, CloneCoalescedChain) {
   auto b = IOBuf::createChain(1000, 100);
   b->advance(10);