Coverity fixes

CIDs:
dereference before null check:
175439 @ drc.cpp

uninitalized field:
175435 @ point_editor.cpp
174162 @ zone_filler.cpp
163188 @ footprint_info_impl.cpp

logically dead code:
155146 @ pcb_editor_control.cpp

pcbnew/drc.cpp

@@ -409,12 +409,16 @@ void DRC::RunTests( wxTextCtrl* aMessages )
 
     if( m_refillZones )
     {
+        if( aMessages )
             aMessages->AppendText( _( "Refilling all zones...\n" ) );
+
         m_pcbEditorFrame->Fill_All_Zones( caller );
     }
     else
     {
+        if( aMessages )
             aMessages->AppendText( _( "Checking zone fills...\n" ) );
+
         m_pcbEditorFrame->Check_All_Zones( caller );
     }
 

pcbnew/footprint_info_impl.cpp

@@ -295,7 +295,7 @@ bool FOOTPRINT_LIST_IMPL::JoinWorkers()
     if( m_cancelled )
         m_list_timestamp = 0;       // God knows what we got before we were cancelled
     else
-        m_list_timestamp = m_lib_table->GenerateTimestamp( m_library );;
+        m_list_timestamp = m_lib_table->GenerateTimestamp( m_library );
 
     return m_errors.empty();
 }
@@ -303,6 +303,7 @@ bool FOOTPRINT_LIST_IMPL::JoinWorkers()
 
 FOOTPRINT_LIST_IMPL::FOOTPRINT_LIST_IMPL() :
     m_loader( nullptr ),
+    m_library( nullptr ),
     m_count_finished( 0 ),
     m_list_timestamp( 0 ),
     m_progress_reporter( nullptr ),

pcbnew/tools/pcb_editor_control.cpp

@@ -700,6 +700,7 @@ static bool mergeZones( BOARD_COMMIT& aCommit, std::vector<ZONE_CONTAINER *>& aO
     return true;
 }
 
+
 int PCB_EDITOR_CONTROL::ZoneMerge( const TOOL_EVENT& aEvent )
 {
     const SELECTION& selection = m_toolMgr->GetTool<SELECTION_TOOL>()->GetSelection();
@@ -726,8 +727,6 @@ int PCB_EDITOR_CONTROL::ZoneMerge( const TOOL_EVENT& aEvent )
 
         netcode = curr_area->GetNetCode();
 
-        if( firstZone )
-        {
         if( firstZone->GetNetCode() != netcode )
             continue;
 
@@ -745,11 +744,6 @@ int PCB_EDITOR_CONTROL::ZoneMerge( const TOOL_EVENT& aEvent )
 
         toMerge.push_back( curr_area );
     }
-        else
-        {
-            toMerge.push_back( curr_area );
-        }
-    }
 
     m_toolMgr->RunAction( PCB_ACTIONS::selectionClear, true );
 

pcbnew/tools/point_editor.cpp

@@ -219,7 +219,7 @@ private:
 
 POINT_EDITOR::POINT_EDITOR() :
     PCB_TOOL( "pcbnew.PointEditor" ), m_selectionTool( NULL ), m_editedPoint( NULL ),
-    m_original( VECTOR2I( 0, 0 ) ), m_altConstrainer( VECTOR2I( 0, 0 ) )
+    m_original( VECTOR2I( 0, 0 ) ), m_altConstrainer( VECTOR2I( 0, 0 ) ), m_refill( false )
 {
 }
 

pcbnew/zone_filler.cpp

@@ -66,7 +66,8 @@ static double s_thermalRot = 450;    // angle of stubs in thermal reliefs for ro
 static const bool s_DumpZonesWhenFilling = false;
 
 ZONE_FILLER::ZONE_FILLER(  BOARD* aBoard, COMMIT* aCommit ) :
-    m_board( aBoard ), m_commit( aCommit ), m_progressReporter( nullptr ), m_count_done( 0 )
+    m_board( aBoard ), m_commit( aCommit ), m_progressReporter( nullptr ),
+    m_next( 0 ), m_count_done( 0 )
 {
 }