2 files changed, 12 insertions, 6 deletions
diff --git a/third_party/abseil_cpp/absl/strings/internal/str_format/convert_test.cc b/third_party/abseil_cpp/absl/strings/internal/str_format/convert_test.cc
index 20c6229fcb37..0e8535c27b7a 100644
--- a/third_party/abseil_cpp/absl/strings/internal/str_format/convert_test.cc
+++ b/third_party/abseil_cpp/absl/strings/internal/str_format/convert_test.cc
@@ -764,6 +764,12 @@ TEST_F(FormatConvertTest, LongDouble) {
     }
   }
 
+  // Regression tests
+  //
+  // Using a string literal because not all platforms support hex literals or it
+  // might be out of range.
+  doubles.push_back(std::strtold("-0xf.ffffffb5feafffbp-16324L", nullptr));
+
   for (const char *fmt : kFormats) {
     for (char f : {'f', 'F',  //
                    'g', 'G',  //
diff --git a/third_party/abseil_cpp/absl/strings/internal/str_format/float_conversion.cc b/third_party/abseil_cpp/absl/strings/internal/str_format/float_conversion.cc
index a761a5a5f9ce..10e4695411b2 100644
--- a/third_party/abseil_cpp/absl/strings/internal/str_format/float_conversion.cc
+++ b/third_party/abseil_cpp/absl/strings/internal/str_format/float_conversion.cc
@@ -224,13 +224,13 @@ class FractionalDigitGenerator {
   // This function will allocate enough stack space to perform the conversion.
   static void RunConversion(
       uint128 v, int exp, absl::FunctionRef<void(FractionalDigitGenerator)> f) {
+    using Limits = std::numeric_limits<long double>;
     assert(-exp < 0);
-    assert(-exp >= std::numeric_limits<long double>::min_exponent - 128);
-    static_assert(
-        StackArray::kMaxCapacity >=
-            (128 - std::numeric_limits<long double>::min_exponent + 31) / 32,
-        "");
-    StackArray::RunWithCapacity((exp + 31) / 32,
+    assert(-exp >= Limits::min_exponent - 128);
+    static_assert(StackArray::kMaxCapacity >=
+                      (Limits::digits + 128 - Limits::min_exponent + 31) / 32,
+                  "");
+    StackArray::RunWithCapacity((Limits::digits + exp + 31) / 32,
                                 [=](absl::Span<uint32_t> input) {
                                   f(FractionalDigitGenerator(input, v, exp));
                                 });