Refactor: PrivateAutoPtr must be initialized with a value

This avoid the pitfall of forgetting to instantiate the private
implementation.

doomsday/sdk/libcore/include/de/libcore.h

@@ -14,7 +14,7 @@
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
  * General Public License for more details. You should have received a copy of
  * the GNU Lesser General Public License along with this program; if not, see:
- * http://www.gnu.org/licenses</small> 
+ * http://www.gnu.org/licenses</small>
  */
 
 #ifndef LIBCORE_H
@@ -118,7 +118,7 @@
  * must use the platform-specific functions.
  */
 #if defined(UNIX) && defined(DENG2_C_API_ONLY)
-#  include <strings.h> // strcasecmp etc. 
+#  include <strings.h> // strcasecmp etc.
 #endif
 
 /*
@@ -180,7 +180,7 @@
  * Macro for determining the name of a type (using RTTI).
  */
 #define DENG2_TYPE_NAME(t)  (typeid(t).name())
-    
+
 /**
  * Macro for hiding the warning about an unused parameter.
  */
@@ -351,7 +351,7 @@ class PrivateAutoPtr
     DENG2_NO_ASSIGN(PrivateAutoPtr)
 
 public:
-    PrivateAutoPtr(InstType *p = 0) : ptr(p) {}
+    PrivateAutoPtr(InstType *p) : ptr(p) {}
     ~PrivateAutoPtr() { reset(); }
 
     InstType &operator * () const { return *ptr; }
@@ -507,7 +507,7 @@ struct LoopResult
     operator int () const { return value; }
     operator GenericLoopResult () const { return GenericLoopResult(value); }
 };
-    
+
 /**
  * All serialization in all contexts use a common protocol version number.
  * Whenever anything changes in serialization, the protocol version needs to be

doomsday/sdk/libcore/src/data/info.cpp

@@ -779,21 +779,21 @@ void Info::BlockElement::moveContents(BlockElement &destination)
 Info::Info() : d(new Instance(this))
 {}
 
-Info::Info(String const &source)
+Info::Info(String const &source) : d(nullptr)
 {
     QScopedPointer<Instance> inst(new Instance(this)); // parsing may throw exception
     inst->parse(source);
     d.reset(inst.take());
 }
 
-Info::Info(File const &file)
+Info::Info(File const &file) : d(nullptr)
 {
     QScopedPointer<Instance> inst(new Instance(this)); // parsing may throw exception
     inst->parse(file);
     d.reset(inst.take());
 }
 
-Info::Info(String const &source, IIncludeFinder const &finder)
+Info::Info(String const &source, IIncludeFinder const &finder) : d(nullptr)
 {
     QScopedPointer<Instance> inst(new Instance(this)); // parsing may throw exception
     inst->finder = &finder;

doomsday/sdk/libcore/src/data/pathtreenode.cpp

@@ -14,7 +14,7 @@
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
  * General Public License for more details. You should have received a copy of
  * the GNU Lesser General Public License along with this program; if not, see:
- * http://www.gnu.org/licenses</small> 
+ * http://www.gnu.org/licenses</small>
  */
 
 #include "de/PathTree"
@@ -50,7 +50,7 @@ DENG2_PIMPL_NOREF(PathTree::Node)
     }
 };
 
-PathTree::Node::Node(PathTree::NodeArgs const &args)
+PathTree::Node::Node(PathTree::NodeArgs const &args) : d(nullptr)
 {
     d.reset(new Instance(args.tree, args.type == PathTree::Leaf, args.segmentId, args.parent));
 

doomsday/sdk/libgui/src/graphics/modelbank.cpp

@@ -46,7 +46,9 @@ DENG2_PIMPL(ModelBank)
     Instance(Public *i) : Base(i) {}
 };
 
-ModelBank::ModelBank() : Bank("ModelBank", BackgroundThread)
+ModelBank::ModelBank()
+    : Bank("ModelBank", BackgroundThread)
+    , d(new Instance(this))
 {}
 
 void ModelBank::add(DotPath const &id, String const &sourcePath)