From 6b7bfed40c559c06d2a4e074427dbc24819bd447 Mon Sep 17 00:00:00 2001
From: Victor Zverovich <victor.zverovich@gmail.com>
Date: Tue, 3 Nov 2020 19:19:10 -0800
Subject: [PATCH] Fix fallback float formatter at assymetric bounds (#1976)

---
 include/fmt/format-inl.h | 2 +-
 test/format-test.cc      | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h
index 9a5f85c2..9046de91 100644
--- a/include/fmt/format-inl.h
+++ b/include/fmt/format-inl.h
@@ -2332,7 +2332,7 @@ void fallback_format(Double d, int num_digits, bool binary32, buffer<char>& buf,
       upper = &upper_store;
     }
     denominator.assign_pow10(exp10);
-    denominator <<= 1;
+    denominator <<= shift;
   } else if (exp10 < 0) {
     numerator.assign_pow10(-exp10);
     lower.assign(numerator);
diff --git a/test/format-test.cc b/test/format-test.cc
index 2f12bd15..1f9a208f 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -1317,6 +1317,8 @@ TEST(FormatterTest, FormatDouble) {
   EXPECT_EQ(buffer, format("{:a}", -42.0));
   safe_sprintf(buffer, "%A", -42.0);
   EXPECT_EQ(buffer, format("{:A}", -42.0));
+  EXPECT_EQ("9223372036854775808.000000",
+            format("{:f}", 9223372036854775807.0));
 }
 
 TEST(FormatterTest, PrecisionRounding) {