[gparted] Stop relying on sort order when adding real paths in calibrate (#766349)

[Curtis Gedak <gedakc src gnome org>]

commit b77fef0dd5a85277210ca0cced77cc8abba99c8f
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Sat May 14 20:25:39 2016 +0100

    Stop relying on sort order when adding real paths in calibrate (#766349)
    
    Quoting the relevant comments from GParted_Core::calibrate_partition():
        Re-add the real partition path from libparted.
    
        When creating a copy operation by pasting into unallocated space the
        list of paths for the partition object was set to
        ["Copy of /dev/SRC"] because the partition didn't yet exist before
        the operations were applied.  Additional operations on that new
        partition also got the list of paths set to ["Copy of /dev/SRC"].
        This re-adds the real path to the start of the list making it
        ["/dev/NEW", "Copy of /dev/SRC"].  This provides the real path for
        file system specific tools used during those additional operations
        such mkfs for the format operation or fsck and others for the
        resize/move operation.
    
        FIXME: Having this work just because "/dev/NEW" happens to sort
        before "Copy of /dev/SRC" is ugly!  Probably have a separate display
        path which can be changed at will without affecting the list of real
        paths for the partition.
    
    Having a separate display path is overly complicated and unnecessary.
    Just replace the list of paths with the real one reported by libparted
    if it contained "Copy of /dev/SRC", determined by checking if the file
    exists.  Otherwise continue to add the libparted name as an alternate
    path.  Whole disk devices can never be named "Copy of /dev/SRC" because
    they are not partitioned so never created or deleted by GParted, only
    ever written to, hence don't need the extra exists test logic.
    
    Bug 766349 - Resolve code ugliness with partition path getting set to
                 "copy of /dev/SRC"

 src/GParted_Core.cc |   28 +++++++++++++++++-----------
 1 files changed, 17 insertions(+), 11 deletions(-)
---
diff --git a/src/GParted_Core.cc b/src/GParted_Core.cc
index 55abe27..35d3168 100644
--- a/src/GParted_Core.cc
+++ b/src/GParted_Core.cc
@@ -3431,7 +3431,8 @@ bool GParted_Core::calibrate_partition( Partition & partition, OperationDetail &
 {
        if ( partition .type == TYPE_PRIMARY || partition .type == TYPE_LOGICAL || partition .type == 
TYPE_EXTENDED )
        {
-               operationdetail .add_child( OperationDetail( String::ucompose( _("calibrate %1"), partition 
.get_path() ) ) ) ;
+               Glib::ustring curr_path = partition.get_path();
+               operationdetail.add_child( OperationDetail( String::ucompose( _("calibrate %1"), curr_path ) 
) );
        
                bool success = false;
                PedDevice* lp_device = NULL ;
@@ -3442,9 +3443,9 @@ bool GParted_Core::calibrate_partition( Partition & partition, OperationDetail &
                        {
                                // Virtual partition spanning whole disk device
 
-                               // Re-add the real partition path from libparted.
-                               // (See just below for why this is needed).
-                               partition.add_path( lp_device->path );
+                               // Re-add alternate path from libparted if different.
+                               if ( curr_path != lp_device->path )
+                                       partition.add_path( lp_device->path );
 
                                success = true;
                        }
@@ -3475,13 +3476,18 @@ bool GParted_Core::calibrate_partition( Partition & partition, OperationDetail &
                                        // tools used during those additional operations
                                        // such mkfs for the format operation or fsck and
                                        // others for the resize/move operation.
-                                       //
-                                       // FIXME: Having this work just because "/dev/NEW"
-                                       // happens to sort before "Copy of /dev/SRC" is
-                                       // ugly!  Probably have a separate display path
-                                       // which can be changed at will without affecting
-                                       // the list of real paths for the partition.
-                                       partition.add_path( get_partition_path( lp_partition ) );
+                                       Glib::ustring new_path = get_partition_path( lp_partition );
+                                       if ( curr_path != new_path )
+                                       {
+                                               if ( ! file_test( curr_path, Glib::FILE_TEST_EXISTS ) )
+                                                       // Current path doesn't exist, so assume
+                                                       // it's "Copy of /dev/SRC" and replace
+                                                       // with real path from libparted.
+                                                       partition.add_path( new_path, true );
+                                               else
+                                                       // Add alternate path from libparted.
+                                                       partition.add_path( new_path );
+                                       }
 
                                        // Reload the partition boundaries from libparted
                                        // to ensure that GParted knows what the actual