From 3b61b9fc4834beb5dcff6aaa987947b4ce959b9b Mon Sep 17 00:00:00 2001
From: Takashi Sawanaka <sdottaka@users.sourceforge.net>
Date: Mon, 22 Oct 2018 23:14:23 +0900
Subject: [PATCH] Write an error message to the console when unknown
 command-line option is specified

---
 Src/Merge.cpp            | 21 ++++++++++++++-------
 Src/MergeCmdLineInfo.cpp |  4 ++++
 Src/MergeCmdLineInfo.h   |  2 ++
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/Src/Merge.cpp b/Src/Merge.cpp
index 9d2fc64ee..60c5814ae 100644
--- a/Src/Merge.cpp
+++ b/Src/Merge.cpp
@@ -204,6 +204,19 @@ BOOL CMergeApp::InitInstance()
 
 	Options::Init(m_pOptions.get()); // Implementation in OptionsInit.cpp
 	ApplyCommandLineConfigOptions(cmdInfo);
+	if (cmdInfo.m_sErrorMessages.size() > 0)
+	{
+		if (AttachConsole(static_cast<DWORD>(-1)))
+		{
+			DWORD dwWritten;
+			for (auto& msg : cmdInfo.m_sErrorMessages)
+			{
+				String line = _T("WinMerge: ") + msg + _T("\n");
+				WriteConsole(GetStdHandle(STD_OUTPUT_HANDLE), line.c_str(), static_cast<DWORD>(line.length()), &dwWritten, NULL);
+			}
+			FreeConsole();
+		}
+	}
 
 	// Initialize temp folder
 	SetupTempPath();
@@ -571,13 +584,7 @@ void CMergeApp::ApplyCommandLineConfigOptions(MergeCmdLineInfo& cmdInfo)
 			}
 			else
 			{
-				String msg = strutils::format_string1(_T("WinMerge: Invalid key '%1' specified in /config option\n"), it.first);
-				if (AttachConsole(static_cast<DWORD>(-1)))
-				{
-					DWORD dwWritten;
-					WriteConsole(GetStdHandle(STD_OUTPUT_HANDLE), msg.c_str(), static_cast<DWORD>(msg.length()), &dwWritten, NULL);
-					FreeConsole();
-				}
+				cmdInfo.m_sErrorMessages.push_back(strutils::format_string1(_T("Invalid key '%1' specified in /config option"), it.first));
 			}
 		}
 	}
diff --git a/Src/MergeCmdLineInfo.cpp b/Src/MergeCmdLineInfo.cpp
index ebc971cd5..1f0af4615 100644
--- a/Src/MergeCmdLineInfo.cpp
+++ b/Src/MergeCmdLineInfo.cpp
@@ -383,6 +383,10 @@ void MergeCmdLineInfo::ParseWinMergeCmdLine(const TCHAR *q)
 		{
 			q = SetConfig(q);
 		}
+		else
+		{
+			m_sErrorMessages.push_back(_T("Unknown option '/") + param + _T("'"));
+		}
 	}
 	// If "compare file dir" make it "compare file dir\file".
 	if (m_Files.GetSize() >= 2)
diff --git a/Src/MergeCmdLineInfo.h b/Src/MergeCmdLineInfo.h
index 7c796ea07..c476cd58a 100644
--- a/Src/MergeCmdLineInfo.h
+++ b/Src/MergeCmdLineInfo.h
@@ -88,6 +88,8 @@ public:
 
 	std::map<String, String> m_Options;
 
+	std::vector<String> m_sErrorMessages;
+
 private:
 
 	static const TCHAR *EatParam(const TCHAR *, String &, bool *flag = 0);
-- 
2.11.0