From 6c06b70911d2c3c4bb60aac65ad8fc504a12746a Mon Sep 17 00:00:00 2001
From: Peter Ross <pross@xvid.org>
Date: Tue, 1 Mar 2022 19:50:19 +1100
Subject: [PATCH] LibC: Set PRI[xX]8/PRI[xX]16 macros to `x` and `X`

Described in:
  <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/
    inttypes.h.html>

The macros were first added in a7a456002e91d9f13793e23aab4c24519c4e87c7,
but it is not clear why the PRIx16/32 macros were defined as 'b' & 'w'.
PrintfImplementation was never able to parse these values.
---
 Tests/LibC/TestSnprintf.cpp        | 10 ++++++++++
 Userland/Libraries/LibC/inttypes.h |  8 ++++----
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/Tests/LibC/TestSnprintf.cpp b/Tests/LibC/TestSnprintf.cpp
index 7346200922..bfb03d18d7 100644
--- a/Tests/LibC/TestSnprintf.cpp
+++ b/Tests/LibC/TestSnprintf.cpp
@@ -10,6 +10,8 @@
 #include <AK/Random.h>
 #include <AK/StringBuilder.h>
 #include <ctype.h>
+#include <inttypes.h>
+#include <stdint.h>
 #include <stdio.h>
 
 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
@@ -263,3 +265,11 @@ TEST_CASE(hexadecimal_values)
     EXPECT(test_single<int>({ LITERAL("xxx\0"), "|%x|", 0, 3, LITERAL("|0|\0") }));
     EXPECT(test_single<int>({ LITERAL("xxx\0"), "|%#x|", 0, 3, LITERAL("|0|\0") }));
 }
+
+TEST_CASE(inttypes_macros)
+{
+    EXPECT(test_single<uint8_t>({ LITERAL("xxxxx"), "|%" PRIx8 "|", 0xAB, 4, LITERAL("|ab|\0") }));
+    EXPECT(test_single<uint8_t>({ LITERAL("xxxxx"), "|%" PRIX8 "|", 0xAB, 4, LITERAL("|AB|\0") }));
+    EXPECT(test_single<uint16_t>({ LITERAL("xxxxxxx"), "|%" PRIx16 "|", 0xC0DE, 6, LITERAL("|c0de|\0") }));
+    EXPECT(test_single<uint16_t>({ LITERAL("xxxxxxx"), "|%" PRIX16 "|", 0xC0DE, 6, LITERAL("|C0DE|\0") }));
+}
diff --git a/Userland/Libraries/LibC/inttypes.h b/Userland/Libraries/LibC/inttypes.h
index 6c479dd123..695928876d 100644
--- a/Userland/Libraries/LibC/inttypes.h
+++ b/Userland/Libraries/LibC/inttypes.h
@@ -41,10 +41,10 @@ __BEGIN_DECLS
 #    define PRIu64 "lu"
 #    define PRIuPTR "lx"
 #endif
-#define PRIx8 "b"
-#define PRIX8 "hhX"
-#define PRIx16 "w"
-#define PRIX16 "hX"
+#define PRIx8 "x"
+#define PRIX8 "X"
+#define PRIx16 "x"
+#define PRIX16 "X"
 #define PRIx32 "x"
 #define PRIX32 "X"
 #ifndef __x86_64__