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fix(container): add empty check to Heap::pop() to prevent UB #236

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fix(container): add empty check to Heap::pop() to prevent UB #236

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3 changes: 3 additions & 0 deletions src/include/zvec/ailego/container/heap.h
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Original file line number Diff line number Diff line change
Expand Up @@ -91,6 +91,9 @@ class Heap : public TBase {

//! Pop the front element
void pop(void) {
if (TBase::empty()) {
return;
}
Comment on lines +94 to +96
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@greptile-apps greptile-apps bot Mar 17, 2026

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P2 Silent no-op changes documented API contract

The pre-existing test file (tests/ailego/container/heap_test.cc, line 234) explicitly documents the original design intent:

// heap.pop(); // disallowed

This indicates that pop() on an empty heap was intentionally a caller-side precondition, analogous to std::priority_queue::pop() (which is UB when empty). Changing the implementation to a silent no-op reverses that contract without updating the documentation comment, and it can silently mask logic bugs at call sites where the caller incorrectly tracks heap size.

If the intent is truly to make this safe to call unconditionally, the stale // disallowed comment in the test should be removed and a positive test for the empty-pop case should be added to heap_test.cc. As written, the PR description claims "comprehensive test cases" were added but no test file changes appear in the diff.

if (TBase::size() > 1) {
auto last = TBase::end() - 1;
this->replace_heap(TBase::begin(), last, std::move(*last));
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