From 5d334b9ce0137e70a8d1d05f78300d96e0d749a5 Mon Sep 17 00:00:00 2001
From: Alison Winters <alisonatwork@outlook.com>
Date: Sat, 27 Feb 2021 08:10:58 +0000
Subject: [PATCH] Support %lf and %lF in format string

Per C99 this should resolve to double.
---
 libc/fmt/palandprintf.c           | 4 ++++
 test/libc/fmt/palandprintf_test.c | 1 +
 2 files changed, 5 insertions(+)

diff --git a/libc/fmt/palandprintf.c b/libc/fmt/palandprintf.c
index de93e235f..4e6eec662 100644
--- a/libc/fmt/palandprintf.c
+++ b/libc/fmt/palandprintf.c
@@ -215,6 +215,10 @@ hidden int palandprintf(void *fn, void *arg, const char *format, va_list va) {
         signbit = sizeof(intmax_t) * 8 - 1;
         break;
       case 'l':
+        if (format[1] == 'f' || format[1] == 'F') {
+          format++;
+          break;
+        }
         if (format[1] == 'l') format++;
         /* fallthrough */
       case 't': /* ptrdiff_t */
diff --git a/test/libc/fmt/palandprintf_test.c b/test/libc/fmt/palandprintf_test.c
index 4e1c17077..25db155e6 100644
--- a/test/libc/fmt/palandprintf_test.c
+++ b/test/libc/fmt/palandprintf_test.c
@@ -421,6 +421,7 @@ TEST(sprintf, test_float) {
   EXPECT_STREQ("+42.90", Format("%+6.2f", 42.8952));
   EXPECT_STREQ("+42.9", Format("%+5.1f", 42.9252));
   EXPECT_STREQ("42.500000", Format("%f", 42.5));
+  EXPECT_STREQ("42.500000", Format("%lf", 42.5));
   EXPECT_STREQ("42.5", Format("%.1f", 42.5));
   EXPECT_STREQ("42167.000000", Format("%f", 42167.0));
   EXPECT_STREQ("-12345.987654321", Format("%.9f", -12345.987654321));