QbsProjectManager: Fix crash when an install step is removed.

The object has already been deleted when the stepRemoved() signal comes
in, so we call disconnect() on a dangling pointer.

Change-Id: Ife5192f9edbde3d42c96dbcae60d7eb03b051745
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/qbsprojectmanager/qbsrunconfiguration.cpp

@@ -192,6 +192,8 @@ void QbsRunConfiguration::installStepChanged()
 
     if (m_currentBuildStepList) {
         connect(m_currentBuildStepList, SIGNAL(stepInserted(int)), this, SLOT(installStepChanged()));
+        connect(m_currentBuildStepList, SIGNAL(aboutToRemoveStep(int)), this,
+                SLOT(installStepToBeRemoved(int)));
         connect(m_currentBuildStepList, SIGNAL(stepRemoved(int)), this, SLOT(installStepChanged()));
         connect(m_currentBuildStepList, SIGNAL(stepMoved(int,int)), this, SLOT(installStepChanged()));
     }
@@ -199,6 +201,17 @@ void QbsRunConfiguration::installStepChanged()
     emit targetInformationChanged();
 }
 
+void QbsRunConfiguration::installStepToBeRemoved(int pos)
+{
+    QTC_ASSERT(m_currentBuildStepList, return);
+    // TODO: Our logic is rather broken. Users can create as many qbs install steps as they want,
+    // but we ignore all but the first one.
+    if (m_currentBuildStepList->steps().at(pos) != m_currentInstallStep)
+        return;
+    disconnect(m_currentInstallStep, SIGNAL(changed()), this, SIGNAL(targetInformationChanged()));
+    m_currentInstallStep = 0;
+}
+
 QString QbsRunConfiguration::executable() const
 {
     QbsProject *pro = static_cast<QbsProject *>(target()->project());

src/plugins/qbsprojectmanager/qbsrunconfiguration.h

@@ -105,6 +105,7 @@ protected:
 
 private slots:
     void installStepChanged();
+    void installStepToBeRemoved(int pos);
 
 private:
     void setBaseWorkingDirectory(const QString &workingDirectory);