From 73f4eb511cf80cf52b78627347727ca02774b731 Mon Sep 17 00:00:00 2001
From: John Moffett <john.moff@gmail.com>
Date: Thu, 23 Mar 2023 13:52:22 -0400
Subject: [PATCH] Check that the Timestamp String is valid

The current `FormatISO8601DateTime` function will
return an empty string if it encounters an error
when converting the `int64_t` seconds since epoch
to a formatted date time. In the unlikely case that happens,
`strStamped.pop_back()` would be undefined behavior.
---
 src/logging.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/logging.cpp b/src/logging.cpp
index a9b2a2b33a5..2d278bcef80 100644
--- a/src/logging.cpp
+++ b/src/logging.cpp
@@ -352,7 +352,7 @@ std::string BCLog::Logger::LogTimestampStr(const std::string& str)
         const auto now{SystemClock::now()};
         const auto now_seconds{std::chrono::time_point_cast<std::chrono::seconds>(now)};
         strStamped = FormatISO8601DateTime(TicksSinceEpoch<std::chrono::seconds>(now_seconds));
-        if (m_log_time_micros) {
+        if (m_log_time_micros && !strStamped.empty()) {
             strStamped.pop_back();
             strStamped += strprintf(".%06dZ", Ticks<std::chrono::microseconds>(now - now_seconds));
         }