dhewm3log.txt for Windows, update changelog

I was lazy and just renamed SDL_win32_main's stdout.txt - but I still
added the dhewm3log-old.txt backup function.

I also renamed Sys_GetHomeDir() to Win_GetHomeDir() as it's Win32-only

On Windows it's in Documents\My Games\dhewm3\dhewm3log.txt

Changelog.md

@@ -50,14 +50,24 @@ Note: Numbers starting with a "#" like #330 refer to the bugreport with that num
 * `s_alReverbGain` CVar to reduce EFX reverb effect intensity (#365)
 * Pause (looped) sounds when entering menu (#330)
 * Fixes for looped sounds (#390)
-* (Optionally) use libbacktrace on non-Windows platforms for more useful
-  backtraces in case of crashes (usually linked statically)
 * Replace libjpeg with stb_image and libogg/libvorbis(file) with stb_vorbis
     - Now the only required external dependencies should be OpenAL, SDL, zlib
       and optionally libCURL (and of course the C and C++ runtimes)
+* (Optionally) use libbacktrace on non-Windows platforms for more useful
+  backtraces in case of crashes (usually linked statically)
 * Fixed a deadlock (freeze) on Windows when printing messages from another thread
 * Fixed some warnings and uninitialized variables (thanks *turol*!)
 * Work around dmap bug caused by GCC using FMA "optimizations" (#147)
+* Prevent dhewm3 from being run as root on Unix-like systems to improve security
+* Replaced most usages of `strncpy()` with something safer to prevent buffer overflows
+  (remaining cases should be safe).
+    - Just a precaution, I don't know if any of them could actually be exploited,
+      but there were some compiler warnings in newer GCC versions.
+* Console output is now logged to `dhewm3log.txt` (last log is renamed to `dhewm3log-old.txt`)
+    - On Windows it's in `My Documents/My Games/dhewm3/`
+    - On Mac it's in `$HOME/Library/Application Support/dhewm3/`
+    - On other Unix-like systems like Linux it's in `$XDG_DATA_HOME/dhewm3/`
+      (usually `$HOME/.local/share/dhewm3/`)
 
 
 1.5.1 (2021-03-14)

neo/sys/win32/SDL_win32_main.c

@@ -37,7 +37,7 @@
 #endif /* main */
 
 /* The standard output files */
-#define STDOUT_FILE	TEXT("stdout.txt")
+#define STDOUT_FILE	TEXT("dhewm3log.txt") /* DG: renamed this */
 #define STDERR_FILE	TEXT("stderr.txt")
 
 /* Set a variable to tell if the stdio redirect has been enabled. */
@@ -197,7 +197,7 @@ static void cleanup_output(void) {
 	}
 }
 
-extern int Sys_GetHomeDir(char *dst, size_t size);
+extern int Win_GetHomeDir(char *dst, size_t size);
 
 /* Redirect the output (stdout and stderr) to a file */
 static void redirect_output(void)
@@ -209,31 +209,32 @@ static void redirect_output(void)
 	char path[MAX_PATH];
 	struct _stat st;
 
-	// DG: use "My Documents/My Games/dhewm3" to write stdout.txt and stderr.txt
+	/* DG: use "My Documents/My Games/dhewm3" to write stdout.txt and stderr.txt
-	//     instead of the binary, which might not be writable
+	 *     instead of the binary, which might not be writable */
-	Sys_GetHomeDir(path, sizeof(path));
+	Win_GetHomeDir(path, sizeof(path));
 
 	if (_stat(path, &st) == -1) {
-		// oops, "My Documents/My Games/dhewm3" doesn't exist - does My Games/ at least exist?
+		/* oops, "My Documents/My Games/dhewm3" doesn't exist - does My Games/ at least exist? */
 		char myGamesPath[MAX_PATH];
+		char* lastslash;
 		memcpy(myGamesPath, path, MAX_PATH);
-		char* lastslash = strrchr(myGamesPath, '/');
+		lastslash = strrchr(myGamesPath, '/');
 		if (lastslash != NULL) {
 			*lastslash = '\0';
 		}
 		if (_stat(myGamesPath, &st) == -1) {
-			// if My Documents/My Games/ doesn't exist, create it
+			/* if My Documents/My Games/ doesn't exist, create it */
 			_mkdir(myGamesPath);
 		}
 		
-		_mkdir(path); // create My Documents/My Games/dhewm3/
+		_mkdir(path); /* create My Documents/My Games/dhewm3/ */
 	}
 	
 
 #endif
 	FILE *newfp;
 
-#if 0 // DG: don't do this anymore.
+#if 0 /* DG: don't do this anymore. */
 	DWORD pathlen;
 	pathlen = GetModuleFileName(NULL, path, SDL_arraysize(path));
 	while ( pathlen > 0 && path[pathlen] != '\\' ) {
@@ -250,6 +251,20 @@ static void redirect_output(void)
 	SDL_strlcat( stdoutPath, DIR_SEPERATOR STDOUT_FILE, SDL_arraysize(stdoutPath) );
 #endif
 
+	{ /* DG: rename old stdout log */
+#ifdef _WIN32_WCE
+		wchar_t stdoutPathBK[MAX_PATH];
+		wcsncpy( stdoutPathBK, path, SDL_arraysize(stdoutPath) );
+		wcsncat( stdoutPathBK, DIR_SEPERATOR TEXT("dhewm3log-old.txt"), SDL_arraysize(stdoutPath) );
+		_wrename( stdoutPath, stdoutpathBK );
+#else
+		char stdoutPathBK[MAX_PATH];
+		SDL_strlcpy( stdoutPathBK, path, SDL_arraysize(stdoutPath) );
+		SDL_strlcat( stdoutPathBK, DIR_SEPERATOR TEXT("dhewm3log-old.txt"), SDL_arraysize(stdoutPath) );
+		rename( stdoutPath, stdoutPathBK );
+#endif
+	} /* DG end */
+
 	/* Redirect standard input and standard output */
 	newfp = freopen(stdoutPath, TEXT("w"), stdout);
 

neo/sys/win32/win_main.cpp

@@ -377,7 +377,7 @@ static int WPath2A(char *dst, size_t size, const WCHAR *src) {
 /*
 ==============
 Returns "My Documents"/My Games/dhewm3 directory (or equivalent - "CSIDL_PERSONAL").
-To be used with Sys_DefaultSavePath(), so savegames, screenshots etc will be
+To be used with Sys_GetPath(PATH_SAVE), so savegames, screenshots etc will be
 saved to the users files instead of systemwide.
 
 Based on (with kind permission) Yamagi Quake II's Sys_GetHomeDir()
@@ -386,7 +386,7 @@ Returns the number of characters written to dst
 ==============
  */
 extern "C" { // DG: I need this in SDL_win32_main.c
-	int Sys_GetHomeDir(char *dst, size_t size)
+	int Win_GetHomeDir(char *dst, size_t size)
 	{
 		int len;
 		WCHAR profile[MAX_OSPATH];
@@ -481,7 +481,7 @@ bool Sys_GetPath(sysPath_t type, idStr &path) {
 
 	case PATH_CONFIG:
 	case PATH_SAVE:
-		if (Sys_GetHomeDir(buf, sizeof(buf)) < 1) {
+		if (Win_GetHomeDir(buf, sizeof(buf)) < 1) {
 			Sys_Error("ERROR: Couldn't get dir to home path");
 			return false;
 		}
@@ -748,6 +748,11 @@ void Sys_Init( void ) {
 #if 0
 	cmdSystem->AddCommand( "setAsyncSound", Sys_SetAsyncSound_f, CMD_FL_SYSTEM, "set the async sound option" );
 #endif
+	{
+		idStr savepath;
+		Sys_GetPath( PATH_SAVE, savepath );
+		common->Printf( "Logging console output to %s/dhewm3log.txt\n", savepath.c_str() );
+	}
 
 	//
 	// Windows version
@@ -1002,6 +1007,16 @@ WinMain
 ==================
 */
 int main(int argc, char *argv[]) {
+	// SDL_win32_main.c creates the dhewm3log.txt and redirects stdout into it
+	// so here we can log its (approx.) creation time before anything else is logged:
+	{
+		time_t tt = time(NULL);
+		const struct tm* tms = localtime(&tt);
+		char timeStr[64] = {};
+		strftime(timeStr, sizeof(timeStr), "%F %H:%M:%S", tms);
+		printf("Opened this log at %s\n", timeStr);
+	}
+
 	const HCURSOR hcurSave = ::SetCursor( LoadCursor( 0, IDC_WAIT ) );
 
 	InitializeCriticalSection( &printfCritSect );