regression: unable to copy files with accentuated chars from an ftp source

[P]

since upgrade to vivid from ubiquity, i am now unable to copy files from an ftp source to a localdisk destination if the filename contains french accentuated chars.

to reproduce :
put some files with the following name for example on a ftp server without double quotes :
"1 - 07 - Le Carnet à spirale.flac"

Start dolphin and put it in double view mode
on the left put the view of files on the ftp server
on the right put a view of a local directory

Problems :
- try to copy the file above from left to right => ERROR windows pops up with "unable to read <filename>"
- try to rename ftp file on the left => ERROR windows pops up with "unable to rename <filename>"

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: dolphin 4:14.12.3-0ubuntu3
ProcVersionSignature: Ubuntu 3.19.0-15.15-lowlatency 3.19.3
Uname: Linux 3.19.0-15-lowlatency x86_64
ApportVersion: 2.17.2-0ubuntu1
Architecture: amd64
CurrentDesktop: KDE
Date: Mon May 4 19:46:01 2015
InstallationDate: Installed on 2015-01-03 (121 days ago)
InstallationMedia: Kubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
SourcePackage: kde-baseapps
UpgradeStatus: Upgraded to vivid on 2015-04-23 (10 days ago)