Fix a bug in iterator validation code in which we don't update the table's…

Fix a bug in iterator validation code in which we don't update the table's reserved growth if the reservation wouldn't grow the table.

PiperOrigin-RevId: 497246219
Change-Id: I9671236f56d10851c49de71c21899368be6c3a00

absl/container/internal/raw_hash_set.h

@@ -2064,8 +2064,8 @@ class raw_hash_set {
       // This is after resize, to ensure that we have completed the allocation
       // and have potentially sampled the hashtable.
       infoz().RecordReservation(n);
-      common().reset_reserved_growth(n);
     }
+    common().reset_reserved_growth(n);
   }
 
   // Extension API: support for heterogeneous keys.

absl/container/internal/raw_hash_set_test.cc

@@ -2292,6 +2292,21 @@ TEST(Table, InvalidIteratorUseWithReserve) {
   EXPECT_DEATH_IF_SUPPORTED(*it, kInvalidIteratorDeathMessage);
 }
 
+TEST(Table, ReservedGrowthUpdatesWhenTableDoesntGrow) {
+  IntTable t;
+  for (int i = 0; i < 8; ++i) t.insert(i);
+  // Want to insert twice without invalidating iterators so reserve.
+  const size_t cap = t.capacity();
+  t.reserve(t.size() + 2);
+  // We want to be testing the case in which the reserve doesn't grow the table.
+  ASSERT_EQ(cap, t.capacity());
+  auto it = t.find(0);
+  t.insert(100);
+  t.insert(200);
+  // `it` shouldn't have been invalidated.
+  EXPECT_EQ(*it, 0);
+}
+
 }  // namespace
 }  // namespace container_internal
 ABSL_NAMESPACE_END