From 6fb8f5f17c079a7d32c855eae313c740e5f9e6be Mon Sep 17 00:00:00 2001
From: practicalswift <practicalswift@users.noreply.github.com>
Date: Thu, 27 Jul 2017 01:09:05 +0200
Subject: [PATCH 1/2] Check that -blocknotify command is non-empty before
 executing

To make BlockNotifyCallback(...) (-blocknotify) consistent with:
* AlertNotify(...) (-alertnotify)
* AddToWallet(...) (-walletnotify)
---
 src/init.cpp          | 7 ++++---
 src/wallet/wallet.cpp | 2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/init.cpp b/src/init.cpp
index d79c2967b97..873a87c009d 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -547,9 +547,10 @@ static void BlockNotifyCallback(bool initialSync, const CBlockIndex *pBlockIndex
         return;
 
     std::string strCmd = gArgs.GetArg("-blocknotify", "");
-
-    boost::replace_all(strCmd, "%s", pBlockIndex->GetBlockHash().GetHex());
-    boost::thread t(runCommand, strCmd); // thread runs free
+    if (!strCmd.empty()) {
+        boost::replace_all(strCmd, "%s", pBlockIndex->GetBlockHash().GetHex());
+        boost::thread t(runCommand, strCmd); // thread runs free
+    }
 }
 
 static bool fHaveGenesis = false;
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 599e74149c5..41ecec9b6b7 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -988,7 +988,7 @@ bool CWallet::AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose)
     // notify an external script when a wallet transaction comes in or is updated
     std::string strCmd = gArgs.GetArg("-walletnotify", "");
 
-    if ( !strCmd.empty())
+    if (!strCmd.empty())
     {
         boost::replace_all(strCmd, "%s", wtxIn.GetHash().GetHex());
         boost::thread t(runCommand, strCmd); // thread runs free

From cffe85f975413441b8fbc5bda82fd2c9d75476f5 Mon Sep 17 00:00:00 2001
From: practicalswift <practicalswift@users.noreply.github.com>
Date: Thu, 27 Jul 2017 11:35:01 +0200
Subject: [PATCH 2/2] Skip sys::system(...) call in case of empty command

---
 src/util.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/util.cpp b/src/util.cpp
index ba563478fad..be76f2696f3 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -812,6 +812,7 @@ fs::path GetSpecialFolderPath(int nFolder, bool fCreate)
 
 void runCommand(const std::string& strCommand)
 {
+    if (strCommand.empty()) return;
     int nErr = ::system(strCommand.c_str());
     if (nErr)
         LogPrintf("runCommand error: system(%s) returned %d\n", strCommand, nErr);