Remove saving and loading (and client matching by) WM_COMMAND.

This legacy session management scheme using the WM_COMMAND property
seems to be called XSM. It is very, very legacy because it was
superseded by XSMP in 1993(!).

By inspecting ~/.config/session/kwin_[...] I could see that Firefox
still sets WM_COMMAND, but nothing else in a regular session with
some applications.
As one of the last applications to switch to XSMP session management,
I guess Firefox keeps doing that because it still needs to work on,
say, Solaris, anyway, so why not set WM_COMMAND on Linux as well.
The WM_COMMAND set by Firefox looks like "wmCommand8=firefox\s" in
the kwin session file. It doesn't actually contain a session
identifier. But then, Firefox only has one session per user anyway.

This goes together with commit 5f0ca1305db4a925 in plasma-workspace /
ksmserver to remove legacy session management support.

I've talked about my plan to do this on IRC with Martin so hopefully
it's okay to just do this now.

activities.cpp

@@ -169,7 +169,7 @@ void Activities::reallyStop(const QString &id)
         const Client* c = (*it);
         const QByteArray sessionId = c->sessionId();
         if (sessionId.isEmpty()) {
-            continue; //TODO support old wm_command apps too?
+            continue;
         }
 
         //qDebug() << sessionId;

sm.cpp

@@ -109,12 +109,8 @@ void Workspace::storeSession(KConfig* config, SMSavePhase phase)
     for (ClientList::Iterator it = clients.begin(); it != clients.end(); ++it) {
         Client* c = (*it);
         QByteArray sessionId = c->sessionId();
-        QByteArray wmCommand = c->wmCommand();
         if (sessionId.isEmpty())
-            // remember also applications that are not XSMP capable
-            // and use the obsolete WM_COMMAND / WM_SAVE_YOURSELF
-            if (wmCommand.isEmpty())
-                continue;
+            continue;
         count++;
         if (c->isActive())
             active_client = count;
@@ -144,7 +140,6 @@ void Workspace::storeClient(KConfigGroup &cg, int num, Client *c)
     QString n = QString::number(num);
     cg.writeEntry(QLatin1String("sessionId") + n, c->sessionId().constData());
     cg.writeEntry(QLatin1String("windowRole") + n, c->windowRole().constData());
-    cg.writeEntry(QLatin1String("wmCommand") + n, c->wmCommand().constData());
     cg.writeEntry(QLatin1String("resourceName") + n, c->resourceName().constData());
     cg.writeEntry(QLatin1String("resourceClass") + n, c->resourceClass().constData());
     cg.writeEntry(QLatin1String("geometry") + n, QRect(c->calculateGravitation(true), c->clientSize()));   // FRAME
@@ -185,12 +180,8 @@ void Workspace::storeSubSession(const QString &name, QSet<QByteArray> sessionIds
     for (ClientList::Iterator it = clients.begin(); it != clients.end(); ++it) {
         Client* c = (*it);
         QByteArray sessionId = c->sessionId();
-        QByteArray wmCommand = c->wmCommand();
         if (sessionId.isEmpty())
-            // remember also applications that are not XSMP capable
-            // and use the obsolete WM_COMMAND / WM_SAVE_YOURSELF
-            if (wmCommand.isEmpty())
-                continue;
+            continue;
         if (!sessionIds.contains(sessionId))
             continue;
 
@@ -230,7 +221,6 @@ void Workspace::addSessionInfo(KConfigGroup &cg)
         session.append(info);
         info->sessionId = cg.readEntry(QLatin1String("sessionId") + n, QString()).toLatin1();
         info->windowRole = cg.readEntry(QLatin1String("windowRole") + n, QString()).toLatin1();
-        info->wmCommand = cg.readEntry(QLatin1String("wmCommand") + n, QString()).toLatin1();
         info->resourceName = cg.readEntry(QLatin1String("resourceName") + n, QString()).toLatin1();
         info->resourceClass = cg.readEntry(QLatin1String("resourceClass") + n, QString()).toLower().toLatin1();
         info->geometry = cg.readEntry(QLatin1String("geometry") + n, QRect());
@@ -279,7 +269,6 @@ SessionInfo* Workspace::takeSessionInfo(Client* c)
     SessionInfo *realInfo = 0;
     QByteArray sessionId = c->sessionId();
     QByteArray windowRole = c->windowRole();
-    QByteArray wmCommand = c->wmCommand();
     QByteArray resourceName = c->resourceName();
     QByteArray resourceClass = c->resourceClass();
 
@@ -313,10 +302,8 @@ SessionInfo* Workspace::takeSessionInfo(Client* c)
             if (info->resourceName == resourceName
                     && info->resourceClass == resourceClass
                     && sessionInfoWindowTypeMatch(c, info)) {
-                if (wmCommand.isEmpty() || info->wmCommand == wmCommand) {
-                    realInfo = info;
-                    session.removeAll(info);
-                }
+                realInfo = info;
+                session.removeAll(info);
             }
         }
     }

sm.h

@@ -41,7 +41,6 @@ class Client;
 struct SessionInfo {
     QByteArray sessionId;
     QByteArray windowRole;
-    QByteArray wmCommand;
     QByteArray wmClientMachine;
     QByteArray resourceName;
     QByteArray resourceClass;

toplevel.cpp

@@ -177,19 +177,6 @@ QByteArray Toplevel::sessionId() const
     return result;
 }
 
-/*!
-  Returns command property for this client,
-  taken either from its window or from the leader window.
- */
-QByteArray Toplevel::wmCommand()
-{
-    QByteArray result = Xcb::StringProperty(window(), XCB_ATOM_WM_COMMAND);
-    if (result.isEmpty() && wmClientLeaderWin && wmClientLeaderWin != window())
-        result = Xcb::StringProperty(wmClientLeaderWin, XCB_ATOM_WM_COMMAND);
-    result.replace(0, ' ');
-    return result;
-}
-
 void Toplevel::getWmClientMachine()
 {
     m_clientMachine->resolve(window(), wmClientLeader());

toplevel.h

@@ -274,7 +274,6 @@ public:
     QByteArray sessionId() const;
     QByteArray resourceName() const;
     QByteArray resourceClass() const;
-    QByteArray wmCommand();
     QByteArray wmClientMachine(bool use_localhost) const;
     const ClientMachine *clientMachine() const;
     Window wmClientLeader() const;