Index: scripts/xfconf-migration-4.6.pl.in
===================================================================
--- a/scripts/xfconf-migration-4.6.pl.in	(revision 29645)
+++ b/scripts/xfconf-migration-4.6.pl.in	(working copy)
@@ -256,6 +256,77 @@
     return $mcs.'.xml';
 }
 
+sub icon_theme_exists
+{
+    my ($dirref,$themename) = @_;
+    my @dirs = @{$dirref};
+
+    foreach my $d (@dirs) {
+        return 1 if(-f "$d/$themename/index.theme");
+    }
+
+    return 0;
+}
+
+sub migrate_icon_theme
+{
+    my ($ref,$chan) = @_;
+    my %opts = %{$ref};
+    my $opt = 'Net/IconThemeName';
+
+    return if(!defined($opts{$opt}));
+    my $val = $opts{$opt}->{'value'};
+
+    if(lc($val) eq 'rodent') {
+        # we don't ship rodent anymore, so try to find something suitable
+        my @icondirs;
+        if(defined($ENV{'XDG_DATA_HOME'})) {
+            @icondirs = ( $ENV{'XDG_DATA_HOME'} . '/icons' );
+        } else {
+            @icondirs = ( $ENV{'HOME'} . '/.local/share/icons' );
+        }
+
+        if(defined($ENV{'XDG_DATA_DIRS'})) {
+            push(@icondirs, split(/:/, $ENV{'XDG_DATA_DIRS'}));
+        } else {
+            push(@icondirs, ( '/usr/share/icons', '/usr/local/share/icons' ));
+        }
+
+        $val = undef;
+        foreach my $itheme (('Tango', 'gnome', 'crystalsvg')) {
+            if(icon_theme_exists(\@icondirs, $itheme)) {
+                $val = $itheme;
+                last;
+            }
+        }
+
+        if(!defined($val)) {
+            # pick the first one that is not 'hicolor'
+            foreach my $d (@icondirs) {
+                opendir(DIR, $d) and do {
+                    my @subdirs = grep { $_ ne 'hicolor' && -d "$d/$_" } readdir(DIR);
+                    foreach my $sd (@subdirs) {
+                        if(-f "$d/$sd/index.theme") {
+                            $val = $sd;
+                            last;
+                        }
+                    }
+                    closedir(DIR);
+                };
+                last if(defined($val));
+            }
+
+            if(!defined($val)) {
+                # ok, their system is kinda b0rked; not much we can do
+                warn("Couldn't find a suitable icon theme to migrate to");
+                return;
+            }
+        }
+    }
+
+    xfconf_set($chan, 'string', '/Net/IconThemeName', $val);
+}
+
 sub migrate_xsettings
 {
     my $mcs = 'gtk';
@@ -283,8 +354,7 @@
                      '/Net/CursorBlinkTime', 'int');
     save_xfconf_prop($ref, $chan, 'Net/DndDragThreshold',
                      '/Net/DndDragThreshold', 'int');
-    save_xfconf_prop($ref, $chan, 'Net/IconThemeName',
-                     '/Net/IconThemeName', 'string');
+    migrate_icon_theme($ref, $chan);
     save_xfconf_prop($ref, $chan, 'Net/ThemeName',
                      '/Net/ThemeName', 'string');