Debug logging changes

Don’t write out logs by default unless you are using -server or -daemon
flags
Write debug logs out if you specify the -debuglog flag
Do not write debug logs out if you specify -nodebuglog
Write debug logs out if you specify -debug (overrides all other options)

src/init.cpp

@@ -341,6 +341,7 @@ std::string HelpMessage()
         "  -daemon                " + _("Run in the background as a daemon and accept commands") + "\n" +
 #endif
         "  -testnet               " + _("Use the test network") + "\n" +
+        "  -debuglog              " + +("Write out the debug.log file") + "\n" +
         "  -debug                 " + _("Output extra debugging information. Implies all other -debug* options") + "\n" +
         "  -debugnet              " + _("Output extra network debugging information") + "\n" +
         "  -logtimestamps         " + _("Prepend debug output with timestamp (default: 1)") + "\n" +
@@ -554,6 +555,8 @@ bool AppInit2(boost::thread_group& threadGroup)
     // ********************************************************* Step 3: parameter-to-internal-flags
 
     fDebug = GetBoolArg("-debug");
+    bool defaultWriteToLog = GetBoolArg("-server") || GetBoolArg("-daemon");
+    fWriteDebugLog = fDebug ? fDebug : GetBoolArg("-debuglog", defaultWriteToLog);
     fBenchmark = GetBoolArg("-benchmark");
 
     // -par=0 means autodetect, but nScriptCheckThreads==0 means no concurrency

src/qt/guiutil.cpp

@@ -267,6 +267,13 @@ bool isObscured(QWidget *w)
 
 void openDebugLogfile()
 {
+    // If we are opening it, might as well fire up debugging for this session.
+    if ( ! fWriteDebugLog )
+    {
+        fWriteDebugLog = true;
+        OutputDebugStringF("Starting debug session");
+    }
+
     boost::filesystem::path pathDebug = GetDataDir() / "debug.log";
 
     /* Open debug.log with the associated application */

src/util.cpp

@@ -69,10 +69,12 @@ namespace boost {
 
 using namespace std;
 
+// Seriously? Global hell.
 map<string, string> mapArgs;
 map<string, vector<string> > mapMultiArgs;
 bool fDebug = false;
 bool fDebugNet = false;
+bool fWriteDebugLog = false;
 bool fPrintToConsole = false;
 bool fPrintToDebugger = false;
 bool fDaemon = false;
@@ -237,6 +239,8 @@ static void DebugPrintInit()
 
 int OutputDebugStringF(const char* pszFormat, ...)
 {
+    if ( ! fWriteDebugLog ) return 0;
+
     int ret = 0; // Returns total number of characters written
     if (fPrintToConsole)
     {
@@ -246,7 +250,7 @@ int OutputDebugStringF(const char* pszFormat, ...)
         ret += vprintf(pszFormat, arg_ptr);
         va_end(arg_ptr);
     }
-    else if (!fPrintToDebugger)
+    else if (!fPrintToDebugger && fWriteDebugLog )
     {
         static bool fStartedNewLine = true;
         boost::call_once(&DebugPrintInit, debugPrintInitFlag);

src/util.h

@@ -138,6 +138,7 @@ extern std::map<std::string, std::string> mapArgs;
 extern std::map<std::string, std::vector<std::string> > mapMultiArgs;
 extern bool fDebug;
 extern bool fDebugNet;
+extern bool fWriteDebugLog;
 extern bool fPrintToConsole;
 extern bool fPrintToDebugger;
 extern bool fDaemon;