handle errors in spdlog gracefully (#410)

* handle errors in spdlog gracefully - try to report and avoid termination
* changelog

2 files changed, 31 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 505ca9f3b..76abe8640 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,6 @@
 ##
+- Improvement: Ignore OOM errors in spdlog, just drop the error since we can't do anything useful if we run out of memory here
+- Improvement: Try to catch any exceptions in spdlog error handling to avoid abort termination of process
 - Improvement: Block cache access/write log from writing to log if disk is low on free space
 
 ## 0.2.22
diff --git a/src/zenserver/diag/logging.cpp b/src/zenserver/diag/logging.cpp
index 13270b41d..0f15253cc 100644
--- a/src/zenserver/diag/logging.cpp
+++ b/src/zenserver/diag/logging.cpp
@@ -446,6 +446,35 @@ InitializeLogging(const ZenServerOptions& GlobalOptions)
 		FileSink->set_pattern("[%C-%m-%d.%e %T] [%n] [%l] %v");
 	}
 
+	spdlog::set_error_handler([](const std::string& msg) {
+		if (msg == std::bad_alloc().what())
+		{
+			// Don't report out of memory in spdlog as we usually log in response to errors which will cause another OOM crashing the
+			// program
+			return;
+		}
+		// Bypass zen logging wrapping to reduce potential other error sources
+		if (auto ErrLogger = zen::logging::ErrorLog(); ErrLogger != nullptr)
+		{
+			try
+			{
+				ErrLogger->log(spdlog::level::err, msg);
+			}
+			catch (const std::exception&)
+			{
+				// Just ignore any errors when in error handler
+			}
+		}
+		try
+		{
+			Log().error(msg);
+		}
+		catch (const std::exception&)
+		{
+			// Just ignore any errors when in error handler
+		}
+	});
+
 	const std::string StartLogTime	  = zen::DateTime::Now().ToIso8601();
 	const zen::Oid	  ServerSessionId = zen::GetSessionId();