[gparted] Replace all Partition object copy assignment (#759726)

[Curtis Gedak <gedakc src gnome org>]

commit 656e1709ffdf9853495e4ac6380896a103ac8ef4
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Sun Dec 20 11:28:09 2015 +0000

    Replace all Partition object copy assignment (#759726)
    
    Copy assignment of Partition objects is now only performed in a few
    places in the Operation and OperationResizeMove classes when updating
    the displayed PartitionVector.  (From Refresh_Visual() when each
    operation is visually applied to the display_partitions vector; the
    new_partition from the operation is copy assigned over the top of the
    relevant existing partition in the display_partitions vector).
    
    In general polymorphic copy assignment is complicated [1], and is now
    unnecessary given the above limited use.  All that is needed is a way to
    polymorphically replace one Partition object with another in a
    PartitionVector.
    
    First, prevent further use of Partition object copy assignment by
    providing a private declaration and no implementation, so the compiler
    enforces this.  Second implement and use PartitionVector method
    replace_at() which replaces a pointer to one Partition object with
    another at the specified index in the PartitionVector.
    
    [1] The Assignment Operator Revisited
        [Section:] Virtual assignment
        http://icu-project.org/docs/papers/cpp_report/the_assignment_operator_revisited.html
    
    Bug 759726 - Implement Partition object polymorphism

 include/Partition.h        |    2 ++
 include/PartitionVector.h  |    1 +
 src/Operation.cc           |    8 ++++----
 src/OperationResizeMove.cc |    4 ++--
 src/PartitionVector.cc     |    7 +++++++
 5 files changed, 16 insertions(+), 6 deletions(-)
---
diff --git a/include/Partition.h b/include/Partition.h
index f2e0ebe..0f3c4e1 100644
--- a/include/Partition.h
+++ b/include/Partition.h
@@ -149,6 +149,8 @@ public:
        Byte_Value sector_size ;  //Sector size of the disk device needed for converting to/from sectors and 
bytes.
 
 private:
+       Partition & operator=( Partition & rhs );  // Not implemented copy assignment operator
+
        static void get_usage_triple_helper( Sector stot, Sector s1, Sector s2, Sector s3, int imax, int & 
i1, int & i2, int & i3 ) ;
 
        void sort_paths_and_remove_duplicates() ;
diff --git a/include/PartitionVector.h b/include/PartitionVector.h
index 5eb89b3..4c65e2c 100644
--- a/include/PartitionVector.h
+++ b/include/PartitionVector.h
@@ -71,6 +71,7 @@ public:
        void clear();
        void push_back_adopt( Partition * partition );
        void insert_adopt( iterator position, Partition * partition );
+       void replace_at( size_type n, const Partition * partition );
 
 private:
        std::vector<Partition *> v;
diff --git a/src/Operation.cc b/src/Operation.cc
index 024197d..43cf895 100644
--- a/src/Operation.cc
+++ b/src/Operation.cc
@@ -115,14 +115,14 @@ void Operation::substitute_new( PartitionVector & partitions )
                {
                        index = find_index_original( partitions[index_extended].logicals );
                        if ( index >= 0 )
-                               partitions[index_extended].logicals[index] = *partition_new;
+                               partitions[index_extended].logicals.replace_at( index, partition_new );
                }
        }
        else
        {
                index = find_index_original( partitions );
                if ( index >= 0 )
-                       partitions[index] = *partition_new;
+                       partitions.replace_at( index, partition_new );
        }
 }
 
@@ -152,7 +152,7 @@ void Operation::insert_new( PartitionVector & partitions )
                        index = find_index_new( partitions[index_extended].logicals );
                        if ( index >= 0 )
                        {
-                               partitions[index_extended].logicals[index] = *partition_new;
+                               partitions[index_extended].logicals.replace_at( index, partition_new );
 
                                insert_unallocated( partitions[index_extended].logicals,
                                                    partitions[index_extended].sector_start,
@@ -167,7 +167,7 @@ void Operation::insert_new( PartitionVector & partitions )
                index = find_index_new( partitions );
                if ( index >= 0 )
                {
-                       partitions[index] = *partition_new;
+                       partitions.replace_at( index, partition_new );
 
                        insert_unallocated( partitions, 0, device.length-1, device.sector_size, false );
                }
diff --git a/src/OperationResizeMove.cc b/src/OperationResizeMove.cc
index e6b6c98..aa21023 100644
--- a/src/OperationResizeMove.cc
+++ b/src/OperationResizeMove.cc
@@ -159,7 +159,7 @@ void OperationResizeMove::apply_normal_to_visual( PartitionVector & partitions )
 
                        if ( index >= 0 )
                        {
-                               partitions[index_extended].logicals[index] = *partition_new;
+                               partitions[index_extended].logicals.replace_at( index, partition_new );
                                remove_adjacent_unallocated( partitions[index_extended].logicals, index );
 
                                insert_unallocated( partitions[index_extended].logicals,
@@ -176,7 +176,7 @@ void OperationResizeMove::apply_normal_to_visual( PartitionVector & partitions )
 
                if ( index >= 0 )
                {
-                       partitions[index] = *partition_new;
+                       partitions.replace_at( index, partition_new );
                        remove_adjacent_unallocated( partitions, index ) ;
 
                        insert_unallocated( partitions, 0, device .length -1, device .sector_size, false ) ;
diff --git a/src/PartitionVector.cc b/src/PartitionVector.cc
index 2e7ee1b..630289d 100644
--- a/src/PartitionVector.cc
+++ b/src/PartitionVector.cc
@@ -83,4 +83,11 @@ void PartitionVector::insert_adopt( iterator position, Partition * partition )
        v.insert( position, partition );
 }
 
+void PartitionVector::replace_at( size_type n, const Partition * partition )
+{
+       Partition *p = new Partition( *partition );
+       delete v[n];
+       v[n] = p;
+}
+
 } //GParted