4 files changed, 58 insertions, 9 deletions
diff --git a/absl/strings/cord.cc b/absl/strings/cord.cc
index e9d72fa8..115705a2 100644
--- a/absl/strings/cord.cc
+++ b/absl/strings/cord.cc
@@ -689,13 +689,10 @@ void Cord::InlineRep::AppendArray(absl::string_view src,
       return;
     }
 
-    // Note: we don't concern ourselves if src aliases data stored in the
-    // inlined data of 'this',  as we update the InlineData only at the end.
-    // We are going from an inline size to beyond inline size. Make the new size
-    // either double the inlined size, or the added size + 10%.
-    const size_t size1 = inline_length * 2 + src.size();
-    const size_t size2 = inline_length + src.size() / 10;
-    rep = CordRepFlat::New(std::max<size_t>(size1, size2));
+    // Allocate flat to be a perfect fit on first append exceeding inlined size.
+    // Subsequent growth will use amortized growth until we reach maximum flat
+    // size.
+    rep = CordRepFlat::New(inline_length + src.size());
     appended = std::min(src.size(), rep->flat()->Capacity() - inline_length);
     memcpy(rep->flat()->Data(), data_.as_chars(), inline_length);
     memcpy(rep->flat()->Data() + inline_length, src.data(), appended);
diff --git a/absl/strings/cord_test.cc b/absl/strings/cord_test.cc
index d0296338..06a7bd6c 100644
--- a/absl/strings/cord_test.cc
+++ b/absl/strings/cord_test.cc
@@ -1385,6 +1385,59 @@ TEST_P(CordTest, DiabolicalGrowth) {
                cord.EstimatedMemoryUsage());
 }
 
+// The following tests check support for >4GB cords in 64-bit binaries, and
+// 2GB-4GB cords in 32-bit binaries.  This function returns the large cord size
+// that's appropriate for the binary.
+
+// Construct a huge cord with the specified valid prefix.
+static absl::Cord MakeHuge(absl::string_view prefix) {
+  absl::Cord cord;
+  if (sizeof(size_t) > 4) {
+    // In 64-bit binaries, test 64-bit Cord support.
+    const size_t size =
+        static_cast<size_t>(std::numeric_limits<uint32_t>::max()) + 314;
+    cord.Append(absl::MakeCordFromExternal(
+        absl::string_view(prefix.data(), size),
+        [](absl::string_view s) { DoNothing(s, nullptr); }));
+  } else {
+    // Cords are limited to 32-bit lengths in 32-bit binaries.  The following
+    // tests check for use of "signed int" to represent Cord length/offset.
+    // However absl::string_view does not allow lengths >= (1u<<31), so we need
+    // to append in two parts;
+    const size_t s1 = (1u << 31) - 1;
+    // For shorter cord, `Append` copies the data rather than allocating a new
+    // node. The threshold is currently set to 511, so `s2` needs to be bigger
+    // to not trigger the copy.
+    const size_t s2 = 600;
+    cord.Append(absl::MakeCordFromExternal(
+        absl::string_view(prefix.data(), s1),
+        [](absl::string_view s) { DoNothing(s, nullptr); }));
+    cord.Append(absl::MakeCordFromExternal(
+        absl::string_view("", s2),
+        [](absl::string_view s) { DoNothing(s, nullptr); }));
+  }
+  return cord;
+}
+
+TEST_P(CordTest, HugeCord) {
+  absl::Cord cord = MakeHuge("huge cord");
+  EXPECT_LE(cord.size(), cord.EstimatedMemoryUsage());
+  EXPECT_GE(cord.size() + 100, cord.EstimatedMemoryUsage());
+}
+
+// Tests that Append() works ok when handed a self reference
+TEST_P(CordTest, AppendSelf) {
+  // We run the test until data is ~16K
+  // This guarantees it covers small, medium and large data.
+  std::string control_data = "Abc";
+  absl::Cord data(control_data);
+  while (control_data.length() < 0x4000) {
+    data.Append(data);
+    control_data.append(control_data);
+    ASSERT_EQ(control_data, data);
+  }
+}
+
 TEST_P(CordTest, MakeFragmentedCordFromInitializerList) {
   absl::Cord fragmented =
       absl::MakeFragmentedCord({"A ", "fragmented ", "Cord"});
diff --git a/absl/strings/internal/cord_rep_btree.h b/absl/strings/internal/cord_rep_btree.h
index 303f4580..bbaa7934 100644
--- a/absl/strings/internal/cord_rep_btree.h
+++ b/absl/strings/internal/cord_rep_btree.h
@@ -23,7 +23,6 @@
 #include "absl/base/internal/raw_logging.h"
 #include "absl/base/optimization.h"
 #include "absl/strings/internal/cord_internal.h"
-#include "absl/strings/internal/cord_rep_btree.h"
 #include "absl/strings/internal/cord_rep_flat.h"
 #include "absl/strings/string_view.h"
 #include "absl/types/span.h"
diff --git a/absl/strings/internal/str_format/bind.h b/absl/strings/internal/str_format/bind.h
index 267cc0ef..b26cff66 100644
--- a/absl/strings/internal/str_format/bind.h
+++ b/absl/strings/internal/str_format/bind.h
@@ -100,7 +100,7 @@ class FormatSpecTemplate
   // We use the 'unavailable' attribute to give a better compiler error than
   // just 'method is deleted'.
   // To avoid checking the format twice, we just check that the format is
-  // constexpr. If is it valid, then the overload below will kick in.
+  // constexpr. If it is valid, then the overload below will kick in.
   // We add the template here to make this overload have lower priority.
   template <typename = void>
   FormatSpecTemplate(const char* s)  // NOLINT