From 21a82e1c55af62333463c5e3bfcb502491de03b5 Mon Sep 17 00:00:00 2001
From: Jim Easterbrook <jim@jim-easterbrook.me.uk>
Date: Wed, 4 Dec 2024 13:22:08 +0000
Subject: [PATCH 1/2] DateValue::toRational returns zero if out of range

The "seconds since UNIX epoch" overflows a Rational (int32) in 2038. See
https://github.com/Exiv2/exiv2/issues/3080 for background.

(cherry picked from commit 308e219f641112f645c54b2fee7f22048ed5bd0d)
---
 src/value.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/value.cpp b/src/value.cpp
index 1cbb78e581..2070b4c38e 100644
--- a/src/value.cpp
+++ b/src/value.cpp
@@ -873,7 +873,11 @@ float DateValue::toFloat(size_t n) const {
 }
 
 Rational DateValue::toRational(size_t n) const {
-  return {static_cast<int32_t>(toInt64(n)), 1};
+  const int64_t t = toInt64(n);
+  if (t < std::numeric_limits<int32_t>::min() || t > std::numeric_limits<int32_t>::max()) {
+    return {0, 1};
+  }
+  return {static_cast<int32_t>(t), 1};
 }
 
 TimeValue::TimeValue() : Value(time) {

From 9b7f7e0f2b48bed91fc3be539bb6f8efd77b37de Mon Sep 17 00:00:00 2001
From: Jim Easterbrook <jim@jim-easterbrook.me.uk>
Date: Wed, 4 Dec 2024 14:40:45 +0000
Subject: [PATCH 2/2] Set 'ok_' to false if timestamp overflow error

This is the correct way to indicate that the value conversion failed.

(cherry picked from commit c7a0b78357c62ffb5178efdeed53b51c4800b082)
---
 src/value.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/value.cpp b/src/value.cpp
index 2070b4c38e..c9d031e9b9 100644
--- a/src/value.cpp
+++ b/src/value.cpp
@@ -863,6 +863,7 @@ int64_t DateValue::toInt64(size_t /*n*/) const {
 uint32_t DateValue::toUint32(size_t /*n*/) const {
   const int64_t t = toInt64();
   if (t < 0 || t > std::numeric_limits<uint32_t>::max()) {
+    ok_ = false;
     return 0;
   }
   return static_cast<uint32_t>(t);
@@ -875,6 +876,7 @@ float DateValue::toFloat(size_t n) const {
 Rational DateValue::toRational(size_t n) const {
   const int64_t t = toInt64(n);
   if (t < std::numeric_limits<int32_t>::min() || t > std::numeric_limits<int32_t>::max()) {
+    ok_ = false;
     return {0, 1};
   }
   return {static_cast<int32_t>(t), 1};