From 908496d43dd7c3a7ca1de42b0e0c21aa0498c7df Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Sat, 5 Sep 2020 10:43:01 +0100
Subject: [PATCH] ASan: make copied files in log entries safe at init.

Ensure that if we copy file-names of log entries while startup
logging is active, we free them, but only once startup logging is
disabled, or on shutdown. This is needed to avoid crashes when
we use file-name copying for the Qt message handler.
---
 simgear/debug/logstream.cxx | 33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/simgear/debug/logstream.cxx b/simgear/debug/logstream.cxx
index e843a659..0ccb631e 100644
--- a/simgear/debug/logstream.cxx
+++ b/simgear/debug/logstream.cxx
@@ -139,8 +139,8 @@ public:
         logTimer.stamp();
     }
 
-    virtual void operator()(sgDebugClass c, sgDebugPriority p,
-        const char* file, int line, const std::string& message)
+    void operator()(sgDebugClass c, sgDebugPriority p,
+                    const char* file, int line, const std::string& message) override
     {
         if (!shouldLog(c, p)) return;
 
@@ -448,10 +448,18 @@ public:
         {
             std::lock_guard<std::mutex> g(m_lock);
             m_startupLogging = on;
-            m_startupEntries.clear();
+            clearStartupEntriesLocked();
         }
     }
 
+    void clearStartupEntriesLocked()
+    {
+        std::for_each(m_startupEntries.begin(), m_startupEntries.end(), [](const LogEntry& e) {
+            if (e.freeFilename) free(const_cast<char*>(e.file));
+        });
+        m_startupEntries.clear();
+    }
+
     void run() override
     {
         while (1) {
@@ -474,11 +482,20 @@ public:
                 (*cb)(entry.debugClass, entry.debugPriority,
                     entry.file, entry.line, entry.message);
             }
-            
-            if (entry.freeFilename) {
+
+            // frrr the filename if required. For startup entries
+            // we wait and do this later
+            if (!m_startupLogging && entry.freeFilename) {
                 free(const_cast<char*>(entry.file));
             }
         } // of main thread loop
+
+        // house-keeping, avoid leak warnings if we exit before disabling
+        // startup logging
+        {
+            std::lock_guard<std::mutex> g(m_lock);
+            clearStartupEntriesLocked();
+        }
     }
 
     bool stop()
@@ -536,9 +553,9 @@ public:
         PauseThread pause(this);
         m_logPriority = p;
         m_logClass = c;
-                for (auto cb : m_consoleCallbacks) {
-	        cb->setLogLevels(c, p);
-		}
+        for (auto cb : m_consoleCallbacks) {
+            cb->setLogLevels(c, p);
+        }
     }
 
     bool would_log( sgDebugClass c, sgDebugPriority p ) const