Fix List swap behavior on front, back and adjacent elements

- immediately return if A == B;
- first and last elements (front, back) are updated upon relinking;
- handles a special case of forward and backward adjacent elements.

(cherry picked from commit ac69f092fc)
This commit is contained in:
Andrii Doroshenko (Xrayez) 2020-09-12 23:58:56 +03:00 committed by Rémi Verschelde
parent 564d7101b4
commit 1f42a8a073
No known key found for this signature in database
GPG key ID: C3336907360768E1

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@ -417,24 +417,38 @@ public:
ERR_FAIL_COND(p_A->data != _data);
ERR_FAIL_COND(p_B->data != _data);
if (p_A == p_B) {
return;
}
Element *A_prev = p_A->prev_ptr;
Element *A_next = p_A->next_ptr;
Element *B_prev = p_B->prev_ptr;
Element *B_next = p_B->next_ptr;
p_A->next_ptr = p_B->next_ptr;
p_A->prev_ptr = p_B->prev_ptr;
p_B->next_ptr = A_next;
p_B->prev_ptr = A_prev;
if (p_A->prev_ptr)
p_A->prev_ptr->next_ptr = p_A;
if (p_A->next_ptr)
p_A->next_ptr->prev_ptr = p_A;
if (p_B->prev_ptr)
p_B->prev_ptr->next_ptr = p_B;
if (p_B->next_ptr)
p_B->next_ptr->prev_ptr = p_B;
if (A_prev) {
A_prev->next_ptr = p_B;
} else {
_data->first = p_B;
}
if (B_prev) {
B_prev->next_ptr = p_A;
} else {
_data->first = p_A;
}
if (A_next) {
A_next->prev_ptr = p_B;
} else {
_data->last = p_B;
}
if (B_next) {
B_next->prev_ptr = p_A;
} else {
_data->last = p_A;
}
p_A->prev_ptr = A_next == p_B ? p_B : B_prev;
p_A->next_ptr = B_next == p_A ? p_B : B_next;
p_B->prev_ptr = B_next == p_A ? p_A : A_prev;
p_B->next_ptr = A_next == p_B ? p_A : A_next;
}
/**
* copy the list