From 763a27280ad84fac1e26a9e0322408c1e7af8819 Mon Sep 17 00:00:00 2001
From: Tor Lillqvist <tml@iki.fi>
Date: Tue, 18 Sep 2018 15:27:17 +0300
Subject: [PATCH] Add possiblity to force logging to stderr with environment
 variable

At least LOOLWSD.cpp has a couple of global variables of types that in
their constructors invoke FakeSocket APIs. If we turn on FakeSocket
logging (fakeSocketSetLoggingCallback()) only in the app's
initialization code, we will miss logging from those global variable
constructors.

Sure, the clean solution would be to turn those global variables into
members in the LOOLWSD class instead, but this will do for now.
---
 net/FakeSocket.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/FakeSocket.cpp b/net/FakeSocket.cpp
index 9c83df4ce..99480dc4d 100644
--- a/net/FakeSocket.cpp
+++ b/net/FakeSocket.cpp
@@ -13,6 +13,8 @@
 
 #include <chrono>
 #include <condition_variable>
+#include <cstdlib>
+#include <iostream>
 #include <sstream>
 #include <mutex>
 #include <thread>
@@ -80,7 +82,10 @@ static std::vector<FakeSocketPair>& getFds()
 
 static std::string flush()
 {
-    if (loggingCallback != nullptr)
+    static bool alwaysStderr = std::getenv("FAKESOCKET_LOG_ALWAYS_STDERR") != nullptr;
+    if (alwaysStderr)
+        std::cerr << loggingBuffer.str() << std::endl;
+    else if (loggingCallback != nullptr)
         loggingCallback(loggingBuffer.str());
     loggingBuffer.str("");
     return "";