widget: reset some deleted vars

only to be shure

src/gui/widget/keyboard_input.cpp

@@ -463,8 +463,10 @@ int CKeyboardInput::exec(CMenuTarget* parent, const std::string &)
 
 	std::string oldval = *valueString;
 
-	if (pixBuf)
+	if (pixBuf) {
 		delete[] pixBuf;
+		pixBuf = NULL;
+	}
 	if (!parent || force_saveScreen) {
 		pixBuf = new fb_pixel_t[(width + OFFSET_SHADOW) * (height + OFFSET_SHADOW)];
 		if (pixBuf)

src/gui/widget/termwindow.cpp

@@ -66,6 +66,7 @@ fprintf(stderr, "%s:%d %s\n", __func__, __LINE__, argv[0]);
 		if (res)
 			*res = ret;
 		delete y;
+		y = NULL;
 fprintf(stderr, "%s:%d\n", __func__, __LINE__);
 		showResult();
 	}

src/gui/widget/yaft/yaft_class.cpp

@@ -211,5 +211,6 @@ exec_failed:
 	sigaction(SIGCHLD, &oldact, NULL);
 init_failed:
 	delete term;
+	term = NULL;
 	return exitcode;
 }

src/gui/widget/yaft/yaft_priv.cpp

@@ -97,8 +97,8 @@ YaFT_p::YaFT_p(bool Paint)
 YaFT_p::~YaFT_p()
 {
 	/* delete NULL is fine */
-	delete font;
-	delete fr;
+	delete font; font = NULL;
+	delete fr; fr = NULL;
 }
 
 bool YaFT_p::init()
@@ -130,8 +130,8 @@ bool YaFT_p::init()
 		shell_ttf = ttx_font_file;
 	if (paint) {
 		for (int i = 0; i < 2; i++) {
-			delete font;
-			delete fr;
+			delete font; font = NULL;
+			delete fr; fr = NULL;
 			fr = new FBFontRenderClass(scalex, scaley);
 			fontstyle = fr->AddFont(shell_ttf.c_str());
 			font = fr->getFont(fr->getFamily(shell_ttf.c_str()).c_str(), fontstyle, height / LINES);