From 4058e117ca775756f6e99c25c4f2e5bec8cf8175 Mon Sep 17 00:00:00 2001
From: fredzio <chardon.frederic@gmail.com>
Date: Sat, 17 Apr 2021 09:12:03 +0200
Subject: [PATCH] Don't clobber game log file when we collect a stack trace.

When the crash catcher catch a signal it forks to collect data about its
parent. In the process the child reinitialize the log file, which ends
up empty.
---
 components/crashcatcher/crashcatcher.cpp | 2 +-
 components/crashcatcher/crashcatcher.hpp | 2 ++
 components/debug/debugging.cpp           | 7 ++++++-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/components/crashcatcher/crashcatcher.cpp b/components/crashcatcher/crashcatcher.cpp
index e0a5c964fa..86571e1e3a 100644
--- a/components/crashcatcher/crashcatcher.cpp
+++ b/components/crashcatcher/crashcatcher.cpp
@@ -43,7 +43,7 @@ namespace bfs = boost::filesystem;
 #include <sys/user.h>
 #endif
 
-static const char crash_switch[] = "--cc-handle-crash";
+#include "crashcatcher.hpp"
 
 static const char fatal_err[] = "\n\n*** Fatal Error ***\n";
 static const char pipe_err[] = "!!! Failed to create pipe\n";
diff --git a/components/crashcatcher/crashcatcher.hpp b/components/crashcatcher/crashcatcher.hpp
index fd8f0d1542..b693ccae43 100644
--- a/components/crashcatcher/crashcatcher.hpp
+++ b/components/crashcatcher/crashcatcher.hpp
@@ -9,6 +9,8 @@
     #define USE_CRASH_CATCHER 0
 #endif
 
+constexpr char crash_switch[] = "--cc-handle-crash";
+
 #if USE_CRASH_CATCHER
 extern void crashCatcherInstall(int argc, char **argv, const std::string &crashLogPath);
 #else
diff --git a/components/debug/debugging.cpp b/components/debug/debugging.cpp
index e9bcf8ad75..0e372942f2 100644
--- a/components/debug/debugging.cpp
+++ b/components/debug/debugging.cpp
@@ -179,7 +179,12 @@ int wrapApplication(int (*innerApplication)(int argc, char *argv[]), int argc, c
         std::cerr.rdbuf (&sb);
 #else
         // Redirect cout and cerr to the log file
-        logfile.open (boost::filesystem::path(cfgMgr.getLogPath() / logName));
+        // If we are collecting a stack trace, append to existing log file
+        std::ios_base::openmode mode = std::ios::out;
+        if(argc == 2 && strcmp(argv[1], crash_switch) == 0)
+            mode |= std::ios::app;
+
+        logfile.open (boost::filesystem::path(cfgMgr.getLogPath() / logName), mode);
 
         coutsb.open (Debug::Tee(logfile, oldcout));
         cerrsb.open (Debug::Tee(logfile, oldcerr));