branch-2.1: [fix](memory) Fix PODArray::add_num_element (#50785)

pick #50756

Author: xinyiZzz

be/src/vec/common/pod_array.h

@@ -389,12 +389,12 @@ class PODArray : public PODArrayBase<sizeof(T), initial_bytes, TAllocator, pad_r
     template <typename U, typename... TAllocatorParams>
     void add_num_element(U&& x, uint32_t num, TAllocatorParams&&... allocator_params) {
         if (num != 0) {
-            const auto new_end = this->c_end + this->byte_size(num);
-            if (UNLIKELY(new_end > this->c_end_of_storage)) {
+            const auto growth_size = this->byte_size(num);
+            if (UNLIKELY(this->c_end + growth_size > this->c_end_of_storage)) {
                 this->reserve(this->size() + num);
             }
             std::fill(t_end(), t_end() + num, x);
-            this->c_end = new_end;
+            this->c_end = this->c_end + growth_size;
         }
     }
 
@@ -420,7 +420,9 @@ class PODArray : public PODArrayBase<sizeof(T), initial_bytes, TAllocator, pad_r
       */
     template <typename... Args>
     void emplace_back(Args&&... args) {
-        if (UNLIKELY(this->c_end == this->c_end_of_storage)) this->reserve_for_next_size();
+        if (UNLIKELY(this->c_end + sizeof(T) > this->c_end_of_storage)) {
+            this->reserve_for_next_size();
+        }
 
         new (t_end()) T(std::forward<Args>(args)...);
         this->c_end += this->byte_size(1);
@@ -457,22 +459,6 @@ class PODArray : public PODArrayBase<sizeof(T), initial_bytes, TAllocator, pad_r
         this->c_end += bytes_to_copy;
     }
 
-    template <typename It1, typename It2>
-    void insert(iterator it, It1 from_begin, It2 from_end) {
-        insert_prepare(from_begin, from_end);
-
-        size_t bytes_to_copy = this->byte_size(from_end - from_begin);
-        size_t bytes_to_move = (end() - it) * sizeof(T);
-
-        if (UNLIKELY(bytes_to_move))
-            memcpy(this->c_end + bytes_to_copy - bytes_to_move, this->c_end - bytes_to_move,
-                   bytes_to_move);
-
-        memcpy(this->c_end - bytes_to_move, reinterpret_cast<const void*>(&*from_begin),
-               bytes_to_copy);
-        this->c_end += bytes_to_copy;
-    }
-
     template <typename It1, typename It2>
     void insert_assume_reserved(It1 from_begin, It2 from_end) {
         size_t bytes_to_copy = this->byte_size(from_end - from_begin);