Cleanup: use nullptr instead of 0 or NULL

src/main_gui.cpp

@@ -309,7 +309,7 @@ struct MainWindow : Window
 			case GHK_REFRESH_SCREEN: MarkWholeScreenDirty(); break;
 
 			case GHK_CRASH: // Crash the game
-				*(volatile byte *)0 = 0;
+				*(volatile byte *)nullptr = 0;
 				break;
 
 			case GHK_MONEY: // Gimme money

src/network/core/tcp_connect.cpp

@@ -268,7 +268,7 @@ bool TCPConnecter::CheckActivity()
 	timeval tv;
 	tv.tv_usec = 0;
 	tv.tv_sec = 0;
-	int n = select(FD_SETSIZE, NULL, &write_fd, NULL, &tv);
+	int n = select(FD_SETSIZE, nullptr, &write_fd, nullptr, &tv);
 	/* select() failed; hopefully next try it doesn't. */
 	if (n < 0) {
 		/* select() normally never fails; so hopefully it works next try! */

src/network/network_command.cpp

@@ -179,7 +179,7 @@ void NetworkSyncCommandQueue(NetworkClientSocket *cs)
 {
 	for (CommandPacket *p = _local_execution_queue.Peek(); p != nullptr; p = p->next) {
 		CommandPacket c = *p;
-		c.callback = 0;
+		c.callback = nullptr;
 		cs->outgoing_queue.Append(&c);
 	}
 }

src/newgrf_commons.h

@@ -309,7 +309,7 @@ bool Convert8bitBooleanCallback(const struct GRFFile *grffile, uint16 cbid, uint
  */
 template <size_t Tcnt>
 struct GRFFilePropsBase {
-	GRFFilePropsBase() : local_id(0), grffile(0)
+	GRFFilePropsBase() : local_id(0), grffile(nullptr)
 	{
 		/* The lack of some compilers to provide default constructors complying to the specs
 		 * requires us to zero the stuff ourself. */

src/os/unix/font_unix.cpp

@@ -51,10 +51,10 @@ FT_Error GetFontByFaceName(const char *font_name, FT_Face *face)
 		/* Resolve the name and populate the information structure */
 		pat = FcNameParse((FcChar8 *)font_family);
 		if (font_style != nullptr) FcPatternAddString(pat, FC_STYLE, (FcChar8 *)font_style);
-		FcConfigSubstitute(0, pat, FcMatchPattern);
+		FcConfigSubstitute(nullptr, pat, FcMatchPattern);
 		FcDefaultSubstitute(pat);
 		fs = FcFontSetCreate();
-		match = FcFontMatch(0, pat, &result);
+		match = FcFontMatch(nullptr, pat, &result);
 
 		if (fs != nullptr && match != nullptr) {
 			int i;

src/os/unix/unix.cpp

@@ -277,7 +277,7 @@ bool GetClipboardContents(char *buffer, const char *last)
 	}
 
 	char *clip = SDL_GetClipboardText();
-	if (clip != NULL) {
+	if (clip != nullptr) {
 		strecpy(buffer, clip, last);
 		SDL_free(clip);
 		return true;

src/video/opengl.cpp

@@ -1309,7 +1309,7 @@ void OpenGLBackend::RenderOglSprite(OpenGLSprite *gl_sprite, PaletteID pal, int
 			_glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
 
 			_glBufferSubData(GL_PIXEL_UNPACK_BUFFER, 0, 256, GetNonSprite(GB(pal, 0, PALETTE_WIDTH), ST_RECOLOUR) + 1);
-			_glTexSubImage1D(GL_TEXTURE_1D, 0, 0, 256, GL_RED, GL_UNSIGNED_BYTE, 0);
+			_glTexSubImage1D(GL_TEXTURE_1D, 0, 0, 256, GL_RED, GL_UNSIGNED_BYTE, nullptr);
 
 			_glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 

src/video/sdl2_v.cpp

@@ -593,7 +593,7 @@ void VideoDriver_SDL_Base::Stop()
 void VideoDriver_SDL_Base::InputLoop()
 {
 	uint32 mod = SDL_GetModState();
-	const Uint8 *keys = SDL_GetKeyboardState(NULL);
+	const Uint8 *keys = SDL_GetKeyboardState(nullptr);
 
 	bool old_ctrl_pressed = _ctrl_pressed;