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COMMON: Fix inserting an array into itself under certain conditions

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This commit is contained in:
Max Horn 2011-05-16 15:23:09 +02:00
parent a564a10e7f
commit 88319a727a
2 changed files with 32 additions and 1 deletions
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5
common/array.h
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@ -293,9 +293,12 @@ protected:
if (n) {
const uint idx = pos - _storage;
T *oldStorage = _storage;
if (_size + n > _capacity) {
if (_size + n > _capacity || (_storage <= first && first <= _storage + _size) ) {
// If there is not enough space, allocate more and
// copy old elements over.
// Likewise, if this is a self-insert, we allocate new
// storage to avoid conflicts. This is not the most efficient
// way to ensure that, but probably the simplest on.
allocCapacity(roundUpCapacity(_size + n));
copy(oldStorage, oldStorage + idx, _storage);
pos = _storage + idx;

28
test/common/array.h
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@ -107,6 +107,34 @@ class ArrayTestSuite : public CxxTest::TestSuite
}
void test_self_insert() {
Common::Array<int> array;
int i;
// Insert some data -- and make sure we have enough space for
// *twice* as much data. This way, there is no need to allocate
// new storage, so if the insert() operation is "clever", it
// will try to reuse the existing storage.
// This in turn may uncover bugs if the insertion code does not
// expect self-insertions.
array.reserve(128);
for (i = 0; i < 64; ++i)
array.push_back(i);
// Now insert the array into the middle of itself
array.insert_at(12, array);
// Verify integrity
TS_ASSERT_EQUALS(array.size(), 128UL);
for (i = 0; i < 12; ++i)
TS_ASSERT_EQUALS(array[i], i);
for (i = 0; i < 64; ++i)
TS_ASSERT_EQUALS(array[i+12], i);
for (i = 12; i < 64; ++i)
TS_ASSERT_EQUALS(array[i+64], i);
}
void test_remove_at() {
Common::Array<int> array;