[gparted] Prevent assert failure from OperationCheck::get_partition_new() (#767233)

[Curtis Gedak <gedakc src gnome org>]

commit 1f2a50544d6b0926e1f02f7eb24cf8503bcc1a02
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Sat Jun 4 09:26:22 2016 +0100

    Prevent assert failure from OperationCheck::get_partition_new() (#767233)
    
    Composing these operations caused GParted to abort on an assert failure:
    (1) Check an existing partition,
    (2) Create a new partition,
    (3) Delete new partition.
    
        # ./gpartedbin
        ======================
        libparted : 2.4
        ======================
        **
        ERROR:OperationCheck.cc:40:virtual GParted::Partition& GParted::OperationCheck::get_partition_new(): 
assertion failed: (false)
        Aborted (core dumped)
    
        # gdb ./gpartedbin core.8876 --batch --quiet --ex backtrace -ex quit
        [New Thread 8876]
        [New Thread 8879]
        [Thread debugging using libthread_db enabled]
        Core was generated by `./gpartedbin'.
        Program terminated with signal 6, Aborted.
        #0  0x000000361f2325e5 in raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
        64        return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
        #0  0x000000361f2325e5 in raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
        #1  0x000000361f233dc5 in abort () at abort.c:92
        #2  0x0000003620a67324 in g_assertion_message (domain=<value optimized out>, file=<value optimized 
out>, line=<value optimized out>, func=0x50f400 "virtual GParted::Partition& 
GParted::OperationCheck::get_partition_new()", message=0x1d37a00 "assertion failed: (false)") at 
gtestutils.c:1358
        #3  0x0000003620a678f0 in g_assertion_message_expr (domain=0x0, file=0x50f1a8 "OperationCheck.cc", 
line=40, func=0x50f400 "virtual GParted::Partition& GParted::OperationCheck::get_partition_new()", 
expr=<value optimized out>) at gtestutils.c:1369
        #4  0x0000000000498e21 in GParted::OperationCheck::get_partition_new (this=0x1d1bb30) at 
OperationCheck.cc:40
        #5  0x00000000004c66ec in GParted::Win_GParted::activate_delete (this=0x7fff031c3e30) at 
Win_GParted.cc:2068
        ...
    
    When Win_GParted::activate_delete() was stepping through the operation
    list removing operations (2 & 3 in the above recreation steps) which
    related to the new partition never to be created it called
    get_partition_new() on all operations in the list.  This included
    calling get_partition_new() on the check operation (1 in the above
    recreation steps).  As partition_new was not set or used by the check
    operation get_partition_new() asserted false and crashed GParted.
    
    Fix by populating the partition_new member in OperationCheck objects,
    thus allowing get_partition_new() to be called on the object.  As a
    check operation doesn't change any partition boundaries or file system
    attributes, just duplicate the new partition from the original
    partition.
    
    Bug 767233 - GParted core dump on assert failure in
                 OperationDelete::get_partition_new()

 include/OperationCheck.h |    3 ---
 src/OperationCheck.cc    |   19 +++----------------
 src/Win_GParted.cc       |    3 +++
 3 files changed, 6 insertions(+), 19 deletions(-)
---
diff --git a/include/OperationCheck.h b/include/OperationCheck.h
index a060201..336d2ea 100644
--- a/include/OperationCheck.h
+++ b/include/OperationCheck.h
@@ -36,9 +36,6 @@ private:
        OperationCheck( const OperationCheck & src );              // Not implemented copy constructor
        OperationCheck & operator=( const OperationCheck & rhs );  // Not implemented copy assignment operator
 
-       Partition & get_partition_new();
-       const Partition & get_partition_new() const;
-
        void create_description() ;
        bool merge_operations( const Operation & candidate );
 } ;
diff --git a/src/OperationCheck.cc b/src/OperationCheck.cc
index 666d646..918853d 100644
--- a/src/OperationCheck.cc
+++ b/src/OperationCheck.cc
@@ -27,28 +27,15 @@ OperationCheck::OperationCheck( const Device & device, const Partition & partiti
 
        this->device = device.get_copy_without_partitions();
        this->partition_original = partition.clone();
+       this->partition_new      = partition.clone();
 }
 
 OperationCheck::~OperationCheck()
 {
        delete partition_original;
+       delete partition_new;
        partition_original = NULL;
-}
-
-Partition & OperationCheck::get_partition_new()
-{
-       g_assert( false );  // Bug: OperationCheck class doesn't use partition_new
-
-       // Not reached.  Return value to keep compiler quiet.
-       return *partition_new;
-}
-
-const Partition & OperationCheck::get_partition_new() const
-{
-       g_assert( false );  // Bug: OperationCheck class doesn't use partition_new
-
-       // Not reached.  Return value to keep compiler quiet.
-       return *partition_new;
+       partition_new = NULL;
 }
 
 void OperationCheck::apply_to_visual( PartitionVector & partitions )
diff --git a/src/Win_GParted.cc b/src/Win_GParted.cc
index 9e66b41..27bd45b 100644
--- a/src/Win_GParted.cc
+++ b/src/Win_GParted.cc
@@ -2640,6 +2640,9 @@ void Win_GParted::activate_check()
        g_assert( selected_partition_ptr != NULL );  // Bug: Partition callback without a selected partition
        g_assert( valid_display_partition_ptr( selected_partition_ptr ) );  // Bug: Not pointing at a valid 
display partition object
 
+       // FIXME: Consider constructing new partition object with zero unallocated and
+       // messages cleared to represent how applying a check operation also grows the
+       // file system to fill the partition.
        Operation * operation = new OperationCheck( devices[current_device], *selected_partition_ptr );
 
        operation ->icon = render_icon( Gtk::Stock::EXECUTE, Gtk::ICON_SIZE_MENU );