Reject array insert(pos, first, last) iterators not pointing into an array

The array-range insert() overload checked that pos fits the current
value and that first/last share the same owning value, but never
verified that value is itself an array. Passing iterators from an
object, a primitive, or null handed value-initialized (singular)
std::vector iterators straight to array_t::insert(), which is
undefined behavior. Add the missing is_array() check, mirroring the
equivalent check already present in the object-range insert()
overload.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
This commit is contained in:
Niels Lohmann
2026-09-05 17:05:57 +02:00
parent 2cee81ae6b
commit 38de588582
4 changed files with 28 additions and 0 deletions
+14
View File
@@ -641,6 +641,20 @@ TEST_CASE("modifiers")
CHECK_THROWS_WITH_AS(j_array.insert(j_array.end(), j_other_array.begin(), j_other_array2.end()), "[json.exception.invalid_iterator.210] iterators do not fit",
json::invalid_iterator&);
}
SECTION("iterators not pointing into an array")
{
json j_object2 = {{"k", 1}, {"l", 2}};
json j_primitive = 5;
json j_null;
CHECK_THROWS_WITH_AS(j_array.insert(j_array.begin(), j_object2.begin(), j_object2.end()), "[json.exception.invalid_iterator.202] iterators first and last must point to arrays",
json::invalid_iterator&);
CHECK_THROWS_WITH_AS(j_array.insert(j_array.begin(), j_primitive.begin(), j_primitive.end()), "[json.exception.invalid_iterator.202] iterators first and last must point to arrays",
json::invalid_iterator&);
CHECK_THROWS_WITH_AS(j_array.insert(j_array.begin(), j_null.begin(), j_null.end()), "[json.exception.invalid_iterator.202] iterators first and last must point to arrays",
json::invalid_iterator&);
}
}
SECTION("range for object")