Do not use std::vector = {} to release memory

Github-Pull: #28452
Rebased-From: 3fcd7fc7ff563bdc0e2bba66b4cbe72d898c876e

1 files changed, 25 insertions, 0 deletions

diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index 0f9f332dc6..a8c611727f 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -2782,4 +2782,29 @@ BOOST_AUTO_TEST_CASE(util_WriteBinaryFile)
     BOOST_CHECK(valid);
     BOOST_CHECK_EQUAL(actual_text, expected_text);
 }
+
+BOOST_AUTO_TEST_CASE(clearshrink_test)
+{
+    {
+        std::vector<uint8_t> v = {1, 2, 3};
+        ClearShrink(v);
+        BOOST_CHECK_EQUAL(v.size(), 0);
+        BOOST_CHECK_EQUAL(v.capacity(), 0);
+    }
+
+    {
+        std::vector<bool> v = {false, true, false, false, true, true};
+        ClearShrink(v);
+        BOOST_CHECK_EQUAL(v.size(), 0);
+        BOOST_CHECK_EQUAL(v.capacity(), 0);
+    }
+
+    {
+        std::deque<int> v = {1, 3, 3, 7};
+        ClearShrink(v);
+        BOOST_CHECK_EQUAL(v.size(), 0);
+        // std::deque has no capacity() we can observe.
+    }
+}
+
 BOOST_AUTO_TEST_SUITE_END()