Program crashes when deleting more than one user script

[Zack Hixon]

When using the User Addons extension, the program crashes when deleting more than one user script.

Steps to reproduce:

Launch Midori
Enable User Addons extension
Open Userscripts panel
Install a few scripts
Restart Midori
Open Userscripts panel
Remove more than one script
Upon removal of the second (or more) script, the program crashes.

about:version:

Command line C:\Program Files (x86)\Midori\bin\midori.exe
Midori 0.5.7 (de.twotoasts.midori_3914e23f5fda7311ea6f07c5733e46f5_fea087517c26fadd409bd4b9dc642555_1_WinSta0_Default)
GTK+ 3.6.4 (3.6.4) Glib 2.34.3 (2.34.3)
WebKitGTK+ 1.10.2 (1.10.2) libSoup 2.40.3
cairo 1.12.10 (1.12.10) libnotify No
gcr No granite No
Platform Windows NT 6.2
Identification Mozilla/5.0 (Windows NT 6.2) AppleWebKit/537.6 (KHTML, like Gecko) Chrome/18.0.1025.133 Safari/537.6 Midori/0.5
Video Formats H264 [x] Ogg Theora [x] WebM [x]

Other extensions being used:

Adobe Acrobat
Advertisement blocker
Cookie Manager
Cookie Security Manager
Toolbar Editor

[gue5t gue5t (gue5t)]

It looks like addons is sloppy in keeping track of references to rows in its treeview, which is repopulated when it notices the filesystem changes (it notices this at most once per second). Thus, if you delete a script and then delete another without waiting a couple seconds in between, the second "delete?" dialog is interrupted by the filesystem change being noticed and loses its reference to the selected row.

[gue5t gue5t (gue5t)]

This is a serious problem because it can lead to either a crash or (as I noticed in testing) deletion of the wrong file!