RemoteLinux: Don't force value for DISPLAY in base environment

When set on nVidia Jetson TX-1, it leads to applications failing.

To allow previously created projects to work, add DISPLAY=:0.0 to user
changes to the base environment the first time the project is loaded. On
new projects for devices using X11 the user now has to manually set the
DISPLAY variable.

Task-number: QTBUG-60665
Change-Id: Iecc192fbad81ad5cbbbcabce6aeb28c3f501d022
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/remotelinux/remotelinuxenvironmentaspect.cpp

@@ -26,6 +26,22 @@
 #include "remotelinuxenvironmentaspect.h"
 
 #include "remotelinuxenvironmentaspectwidget.h"
+#include "utils/algorithm.h"
+
+static const char DISPLAY_KEY[] = "DISPLAY";
+static const char VERSION_KEY[] = "RemoteLinux.EnvironmentAspect.Version";
+static const int ENVIRONMENTASPECT_VERSION = 1; // Version was introduced in 4.3 with the value 1
+
+namespace {
+
+bool displayAlreadySet(const QList<Utils::EnvironmentItem> &changes)
+{
+    return Utils::contains(changes, [](const Utils::EnvironmentItem &item) {
+        return item.name == DISPLAY_KEY;
+    });
+}
+
+} // anonymous namespace
 
 namespace RemoteLinux {
 
@@ -64,9 +80,6 @@ Utils::Environment RemoteLinuxEnvironmentAspect::baseEnvironment() const
     Utils::Environment env;
     if (baseEnvironmentBase() == static_cast<int>(RemoteBaseEnvironment))
         env = m_remoteEnvironment;
-    const QString displayKey = QLatin1String("DISPLAY");
-    if (!env.hasKey(displayKey))
-        env.appendOrSet(displayKey, QLatin1String(":0.0"));
     return env;
 }
 
@@ -93,5 +106,29 @@ QString RemoteLinuxEnvironmentAspect::userEnvironmentChangesAsString() const
     return env.mid(0, env.size() - 1);
 }
 
+void RemoteLinuxEnvironmentAspect::fromMap(const QVariantMap &map)
+{
+    ProjectExplorer::EnvironmentAspect::fromMap(map);
+
+    const auto version = map.value(QLatin1String(VERSION_KEY), 0).toInt();
+    if (version == 0) {
+        // In Qt Creator versions prior to 4.3 RemoteLinux included DISPLAY=:0.0 in the base
+        // environment, if DISPLAY was not set. In order to keep existing projects expecting
+        // that working, add the DISPLAY setting to user changes in them. New projects will
+        // have version 1 and will not get DISPLAY set.
+        auto changes = userEnvironmentChanges();
+        if (!displayAlreadySet(changes)) {
+            changes.append(Utils::EnvironmentItem(QLatin1String(DISPLAY_KEY), QLatin1String(":0.0")));
+            setUserEnvironmentChanges(changes);
+        }
+    }
+}
+
+void RemoteLinuxEnvironmentAspect::toMap(QVariantMap &map) const
+{
+    ProjectExplorer::EnvironmentAspect::toMap(map);
+    map.insert(QLatin1String(VERSION_KEY), ENVIRONMENTASPECT_VERSION);
+}
+
 } // namespace RemoteLinux
 

src/plugins/remotelinux/remotelinuxenvironmentaspect.h

@@ -48,6 +48,10 @@ public:
 
     QString userEnvironmentChangesAsString() const;
 
+protected:
+    void fromMap(const QVariantMap &map) override;
+    void toMap(QVariantMap &map) const override;
+
 private:
     enum BaseEnvironmentBase {
         CleanBaseEnvironment = 0,