[PATCH] qconf: fix SIGSEGV on empty menu items

qconf may cause SIGSEGV by trying to show debug information on empty menu
items

Signed-off-by: Cyrill V. Gorcunov <[e-mail]>
Cc: Roman Zippel <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

scripts/kconfig/qconf.cc

···
 		configSettings->endGroup();
 		connect(configApp, SIGNAL(aboutToQuit()), SLOT(saveSettings()));
 	}
+
+	has_dbg_info = 0;
 }
 
 void ConfigInfoView::saveSettings(void)
···
 	if (menu == m)
 		return;
 	menu = m;
-	if (!menu)
+	if (!menu) {
+		has_dbg_info = 0;
 		clear();
-	else
+	} else {
+		has_dbg_info = 1;
 		menuInfo();
+       }
 }
 
 void ConfigInfoView::setSource(const QString& name)
···
 void ConfigInfoView::symbolInfo(void)
 {
 	QString str;
+
+	if (!has_dbg_info)
+		return;
 
 	str += "<big>Symbol: <b>";
 	str += print_filter(sym->name);

scripts/kconfig/qconf.h

···
 	struct symbol *sym;
 	struct menu *menu;
 	bool _showDebug;
+
+	int has_dbg_info;
 };
 
 class ConfigSearchWindow : public QDialog {