AK: Don't crash in HashTable::clear_with_capacity on an empty table

When calling clear_with_capacity on an empty HashTable/HashMap, a null
deref would occur when trying to memset() m_buckets. Checking that it
has capacity before clearing fixes the issue.

1 files changed, 2 insertions, 0 deletions

diff --git a/AK/HashTable.h b/AK/HashTable.h
index ad6f7de16e..b2d9b6fe08 100644
--- a/AK/HashTable.h
+++ b/AK/HashTable.h
@@ -291,6 +291,8 @@ public:
     }
     void clear_with_capacity()
     {
+        if (m_capacity == 0)
+            return;
         if constexpr (!Detail::IsTriviallyDestructible<T>) {
             for (auto* bucket : *this)
                 bucket->~T();