build: add global var for whether or not the gui is enabled

src/bitcoind.cpp

@@ -123,6 +123,7 @@ extern void noui_connect();
 int main(int argc, char* argv[])
 {
     bool fRet = false;
+    fHaveGUI = false;
 
     // Connect bitcoind signal handlers
     noui_connect();

src/main.cpp

@@ -48,6 +48,7 @@ bool fReindex = false;
 bool fBenchmark = false;
 bool fTxIndex = false;
 unsigned int nCoinCacheSize = 5000;
+bool fHaveGUI = false;
 
 /** Fees smaller than this (in satoshi) are considered zero fee (for transaction creation) */
 int64 CTransaction::nMinTxFee = 10000;  // Override with -mintxfee

src/main.h

@@ -94,6 +94,7 @@ extern bool fBenchmark;
 extern int nScriptCheckThreads;
 extern bool fTxIndex;
 extern unsigned int nCoinCacheSize;
+extern bool fHaveGUI;
 
 // Settings
 extern int64 nTransactionFee;

src/qt/bitcoin.cpp

@@ -113,6 +113,8 @@ static void handleRunawayException(std::exception *e)
 #ifndef BITCOIN_QT_TEST
 int main(int argc, char *argv[])
 {
+    fHaveGUI = true;
+
     // Command-line options take precedence:
     ParseParameters(argc, argv);