Remove BuildStepList::isNull

It's not really needed. The Null-ness is equivalent to a failed
fromMap() which we execute on all usage paths anyways.

Change-Id: I72bb7fb55b7f26680fa68da8eef751ca96380ecd
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/projectexplorer/buildconfiguration.cpp

@@ -173,8 +173,8 @@ bool BuildConfiguration::fromMap(const QVariantMap &map)
             qWarning() << "No data for build step list" << i << "found!";
             continue;
         }
-        auto list = new BuildStepList(this, data);
-        if (list->isNull()) {
+        auto list = new BuildStepList(this, Core::Id());
+        if (!list->fromMap(data)) {
             qWarning() << "Failed to restore build step list" << i;
             delete list;
             return false;

src/plugins/projectexplorer/buildsteplist.cpp

@@ -51,8 +51,7 @@ BuildStepList::BuildStepList(QObject *parent, Core::Id id) :
 }
 
 BuildStepList::BuildStepList(QObject *parent, BuildStepList *source) :
-    ProjectConfiguration(parent, source),
-    m_isNull(source->m_isNull)
+    ProjectConfiguration(parent, source)
 {
     setDisplayName(source->displayName());
     Q_ASSERT(parent);
@@ -61,13 +60,6 @@ BuildStepList::BuildStepList(QObject *parent, BuildStepList *source) :
     // will fail to clone the buildsteps!
 }
 
-BuildStepList::BuildStepList(QObject *parent, const QVariantMap &data) :
-    ProjectConfiguration(parent, Core::Id())
-{
-    Q_ASSERT(parent);
-    m_isNull = !fromMap(data);
-}
-
 BuildStepList::~BuildStepList()
 {
     qDeleteAll(m_steps);
@@ -84,11 +76,6 @@ QVariantMap BuildStepList::toMap() const
     return map;
 }
 
-bool BuildStepList::isNull() const
-{
-    return m_isNull;
-}
-
 int BuildStepList::count() const
 {
     return m_steps.count();

src/plugins/projectexplorer/buildsteplist.h

@@ -43,7 +43,6 @@ class PROJECTEXPLORER_EXPORT BuildStepList : public ProjectConfiguration
 public:
     BuildStepList(QObject *parent, Core::Id id);
     BuildStepList(QObject *parent, BuildStepList *source);
-    BuildStepList(QObject *parent, const QVariantMap &data);
     ~BuildStepList() override;
 
     QList<BuildStep *> steps() const;
@@ -68,7 +67,6 @@ public:
         return result;
     }
 
-    bool isNull() const;
     int count() const;
     bool isEmpty() const;
     bool contains(Core::Id id) const;
@@ -82,6 +80,7 @@ public:
     Target *target() const;
 
     virtual QVariantMap toMap() const override;
+    virtual bool fromMap(const QVariantMap &map) override;
     void cloneSteps(BuildStepList *source);
 
 signals:
@@ -90,12 +89,8 @@ signals:
     void stepRemoved(int position);
     void stepMoved(int from, int to);
 
-protected:
-    virtual bool fromMap(const QVariantMap &map) override;
-
 private:
     QList<BuildStep *> m_steps;
-    bool m_isNull = false;
 };
 
 } // namespace ProjectExplorer

src/plugins/projectexplorer/deployconfiguration.cpp

@@ -116,8 +116,8 @@ bool DeployConfiguration::fromMap(const QVariantMap &map)
     QVariantMap data = map.value(QLatin1String(BUILD_STEP_LIST_PREFIX) + QLatin1Char('0')).toMap();
     if (!data.isEmpty()) {
         delete m_stepList;
-        m_stepList = new BuildStepList(this, data);
-        if (m_stepList->isNull()) {
+        m_stepList = new BuildStepList(this, Core::Id());
+        if (!m_stepList->fromMap(data)) {
             qWarning() << "Failed to restore deploy step list";
             delete m_stepList;
             m_stepList = 0;