From 4d9950d3bc72d92a0ee9a33ab3b77e097eb77354 Mon Sep 17 00:00:00 2001
From: John Newbery <john@johnnewbery.com>
Date: Mon, 10 Apr 2017 10:27:36 -0400
Subject: [PATCH] Set BCLog::LIBEVENT correctly for old libevent versions.

---
 src/httpserver.cpp | 28 ++++++++++++++++++++--------
 src/httpserver.h   |  4 ++++
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/src/httpserver.cpp b/src/httpserver.cpp
index 347433eb11..e7df23295d 100644
--- a/src/httpserver.cpp
+++ b/src/httpserver.cpp
@@ -384,15 +384,13 @@ bool InitHTTPServer()
 
     // Redirect libevent's logging to our own log
     event_set_log_callback(&libevent_log_cb);
-#if LIBEVENT_VERSION_NUMBER >= 0x02010100
-    // If -debug=libevent, set full libevent debugging.
-    // Otherwise, disable all libevent debugging.
-    if (LogAcceptCategory(BCLog::LIBEVENT)) {
-        event_enable_debug_logging(EVENT_DBG_ALL);
-    } else {
-        event_enable_debug_logging(EVENT_DBG_NONE);
+    // Update libevent's log handling. Returns false if our version of
+    // libevent doesn't support debug logging, in which case we should
+    // clear the BCLog::LIBEVENT flag.
+    if (!UpdateHTTPServerLogging(logCategories & BCLog::LIBEVENT)) {
+        logCategories &= ~BCLog::LIBEVENT;
     }
-#endif
+
 #ifdef WIN32
     evthread_use_windows_threads();
 #else
@@ -435,6 +433,20 @@ bool InitHTTPServer()
     return true;
 }
 
+bool UpdateHTTPServerLogging(bool enable) {
+#if LIBEVENT_VERSION_NUMBER >= 0x02010100
+    if (enable) {
+        event_enable_debug_logging(EVENT_DBG_ALL);
+    } else {
+        event_enable_debug_logging(EVENT_DBG_NONE);
+    }
+    return true;
+#else
+    // Can't update libevent logging if version < 02010100
+    return false;
+#endif
+}
+
 std::thread threadHTTP;
 std::future<bool> threadResult;
 
diff --git a/src/httpserver.h b/src/httpserver.h
index b55b253bea..6be9950682 100644
--- a/src/httpserver.h
+++ b/src/httpserver.h
@@ -32,6 +32,10 @@ void InterruptHTTPServer();
 /** Stop HTTP server */
 void StopHTTPServer();
 
+/** Change logging level for libevent. Removes BCLog::LIBEVENT from logCategories if
+ * libevent doesn't support debug logging.*/
+bool UpdateHTTPServerLogging(bool enable);
+
 /** Handler for requests to a certain HTTP path */
 typedef std::function<bool(HTTPRequest* req, const std::string &)> HTTPRequestHandler;
 /** Register handler for prefix.