[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 <gorcunov@gmail.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

scripts/kconfig/qconf.cc

@@ -925,6 +925,8 @@ ConfigInfoView::ConfigInfoView(QWidget* parent, const char *name)
 		configSettings->endGroup();
 		connect(configApp, SIGNAL(aboutToQuit()), SLOT(saveSettings()));
 	}
+
+	has_dbg_info = 0;
 }
 
 void ConfigInfoView::saveSettings(void)
@@ -953,10 +955,13 @@ void ConfigInfoView::setInfo(struct menu *m)
 	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)
@@ -991,6 +996,9 @@ void ConfigInfoView::symbolInfo(void)
 {
 	QString str;
 
+	if (!has_dbg_info)
+		return;
+
 	str += "<big>Symbol: <b>";
 	str += print_filter(sym->name);
 	str += "</b></big><br><br>value: ";

scripts/kconfig/qconf.h

@@ -273,6 +273,8 @@ public slots:
 	struct symbol *sym;
 	struct menu *menu;
 	bool _showDebug;
+
+	int has_dbg_info;
 };
 
 class ConfigSearchWindow : public QDialog {