Disable delete context menu option for undeletable link files

Before this change, it was possible to delete for example a link that
is stored on a read-only file system and it would disappear after
deletion but reappear as soon as the menu restarts.

src/contextmenu.cpp

@@ -35,31 +35,33 @@ ContextMenu::ContextMenu(GMenu2X &gmenu2x, Menu &menu)
 			tr.translate("Add link in $1", menu.selSection().c_str(), NULL),
 			std::bind(&GMenu2X::addLink, &gmenu2x)));
 
-	if (app && !app->getManual().empty()) {
+	if (app) {
+		if (!app->getManual().empty()) {
 			options.push_back(std::make_shared<MenuOption>(
-				tr.translate("Show manual of $1", app->getTitle().c_str(), NULL),
+					tr.translate("Show manual of $1",
+						app->getTitle().c_str(), NULL),
 					std::bind(&GMenu2X::showManual, &gmenu2x)));
 		}
 
-	if (app && app->isEditable()) {
-
 		/* FIXME(percuei): This permits to mask the "Edit link" entry
 		 *                 on the contextual menu in case CPUFREQ support is
 		 *                 not compiled in and the link corresponds to an OPK.
 		 *                 This is not a good idea as it'll break things if
 		 *                 a new config option is added to the contextual menu.
 		 */
-		if (!app->isOpk()
+		if (app->isEditable() && (
+				!app->isOpk()
 #if defined(ENABLE_CPUFREQ)
 				|| true
 #endif
 				|| !app->getSelectorDir().empty()
-				) {
+				)) {
 			options.push_back(std::make_shared<MenuOption>(
 					tr.translate("Edit $1", app->getTitle().c_str(), NULL),
 					std::bind(&GMenu2X::editLink, &gmenu2x)));
 		}
-		if (!app->isOpk()) {
+
+		if (app->isDeletable()) {
 			options.push_back(std::make_shared<MenuOption>(
 					tr.translate("Delete $1", app->getTitle().c_str(), NULL),
 					std::bind(&GMenu2X::deleteLink, &gmenu2x)));

src/linkapp.cpp

@@ -81,12 +81,13 @@ private:
 
 
 #ifdef HAVE_LIBOPK
-LinkApp::LinkApp(GMenu2X *gmenu2x_, const char* linkfile,
+LinkApp::LinkApp(GMenu2X *gmenu2x_, const char* linkfile, bool deletable,
 			struct OPK *opk, const char *metadata_)
 #else
-LinkApp::LinkApp(GMenu2X *gmenu2x_, const char* linkfile)
+LinkApp::LinkApp(GMenu2X *gmenu2x_, const char* linkfile, bool deletable)
 #endif
 	: Link(gmenu2x_, bind(&LinkApp::start, this))
+	, deletable(deletable)
 {
 	manual = "";
 	file = linkfile;

src/linkapp.h

@@ -40,7 +40,7 @@ private:
 	std::string sclock;
 	int iclock;
 	std::string exec, params, workdir, manual, selectordir, selectorfilter;
-	bool selectorbrowser, editable;
+	bool selectorbrowser, deletable, editable;
 
 	std::string file;
 
@@ -61,10 +61,10 @@ public:
 	bool isOpk() { return isOPK; }
 	const std::string &getOpkFile() { return opkFile; }
 
-	LinkApp(GMenu2X *gmenu2x, const char* linkfile,
+	LinkApp(GMenu2X *gmenu2x, const char* linkfile, bool deletable,
 				struct OPK *opk = NULL, const char *metadata = NULL);
 #else
-	LinkApp(GMenu2X *gmenu2x, const char* linkfile);
+	LinkApp(GMenu2X *gmenu2x, const char* linkfile, bool deletable);
 	bool isOpk() { return false; }
 #endif
 
@@ -93,6 +93,7 @@ public:
 	void showManual();
 	void selector(int startSelection=0, const std::string &selectorDir="");
 	bool targetExists();
+	bool isDeletable() { return deletable; }
 	bool isEditable() { return editable; }
 
 	const std::string &getFile() { return file; }

src/menu.cpp

@@ -495,7 +495,7 @@ bool Menu::addLink(string path, string file, string section) {
 
 			INFO("Section: '%s(%i)'\n", sections[isection].c_str(), isection);
 
-			LinkApp* link = new LinkApp(gmenu2x, linkpath.c_str());
+			LinkApp* link = new LinkApp(gmenu2x, linkpath.c_str(), true);
 			link->setSize(gmenu2x->skinConfInt["linkWidth"],gmenu2x->skinConfInt["linkHeight"]);
 			links[isection].push_back( link );
 		}
@@ -698,7 +698,10 @@ void Menu::openPackage(std::string path, bool order)
 		if (!has_metadata)
 		  break;
 
-		link = new LinkApp(gmenu2x, path.c_str(), opk, name);
+		// Note: OPK links can only be deleted by removing the OPK itself,
+		//       but that is not something we want to do in the menu,
+		//       so consider this link undeletable.
+		link = new LinkApp(gmenu2x, path.c_str(), false, opk, name);
 		link->setSize(gmenu2x->skinConfInt["linkWidth"], gmenu2x->skinConfInt["linkHeight"]);
 
 		addSection(link->getCategory());
@@ -844,8 +847,11 @@ void Menu::readLinks() {
 		  + sections[correct], linkfiles);
 
 		sort(linkfiles.begin(), linkfiles.end(),case_less());
-		for (uint x=0; x<linkfiles.size(); x++) {
+		for (auto const& linkfile : linkfiles) {
-			LinkApp *link = new LinkApp(gmenu2x, linkfiles[x].c_str());
+			// Check whether the link file could be deleted.
+			bool deletable = access(parentDir(linkfile).c_str(), W_OK) == 0;
+
+			LinkApp *link = new LinkApp(gmenu2x, linkfile.c_str(), deletable);
 			link->setSize(gmenu2x->skinConfInt["linkWidth"], gmenu2x->skinConfInt["linkHeight"]);
 			if (link->targetExists())
 				links[i].push_back(link);