1 files changed, 20 insertions, 0 deletions
diff --git a/absl/strings/cord_test.cc b/absl/strings/cord_test.cc
index fb673411..710a1b40 100644
--- a/absl/strings/cord_test.cc
+++ b/absl/strings/cord_test.cc
@@ -1316,6 +1316,26 @@ TEST(Cord, Concat_Append) {
   EXPECT_EQ(s2.size(), size + 1);
 }
 
+TEST(Cord, DiabolicalGrowth) {
+  // This test exercises a diabolical Append(<one char>) on a cord, making the
+  // cord shared before each Append call resulting in a terribly fragmented
+  // resulting cord.
+  // TODO(b/183983616): Apply some minimum compaction when copying a shared
+  // source cord into a mutable copy for updates in CordRepRing.
+  RandomEngine rng(testing::GTEST_FLAG(random_seed));
+  const std::string expected = RandomLowercaseString(&rng, 5000);
+  absl::Cord cord;
+  for (char c : expected) {
+    absl::Cord shared(cord);
+    cord.Append(absl::string_view(&c, 1));
+  }
+  std::string value;
+  absl::CopyCordToString(cord, &value);
+  EXPECT_EQ(value, expected);
+  ABSL_RAW_LOG(INFO, "Diabolical size allocated = %zu",
+               cord.EstimatedMemoryUsage());
+}
+
 TEST(MakeFragmentedCord, MakeFragmentedCordFromInitializerList) {
   absl::Cord fragmented =
       absl::MakeFragmentedCord({"A ", "fragmented ", "Cord"});