From eb98d37f4a2ff614889f70f0dfa639ac8600a920 Mon Sep 17 00:00:00 2001
From: Ian Beckwith <ianb@erislabs.net>
Date: Sat, 2 Oct 2010 06:20:52 +0100
Subject: [PATCH] relativise symbolic links

---
 lib/ID3FS/DB.pm   | 38 ++++++++++++++++++++++++++++++++++++--
 lib/ID3FS/Fuse.pm |  5 +++--
 lib/ID3FS/Path.pm |  5 ++---
 3 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/lib/ID3FS/DB.pm b/lib/ID3FS/DB.pm
index 15855b2..9930609 100644
--- a/lib/ID3FS/DB.pm
+++ b/lib/ID3FS/DB.pm
@@ -385,7 +385,7 @@ sub tracks
 
 sub filename
 {
-    my($self, @constraints)=@_;
+    my($self, $mountpoint, @constraints)=@_;
     if(ref($constraints[$#constraints]) eq "ID3FS::PathElement::File")
     {
 	my $id=$constraints[$#constraints]->{id};
@@ -395,11 +395,45 @@ sub filename
 		 "GROUP BY paths.name, files.name");
 	print "FILENAME SQL: $sql\n";
 	my ($path, $name)=$self->cmd_onerow($sql, $id);
-	return($self->{absbase} . "/$path/$name");
+	my $id3fs_path=join('/', map { $_->{name}; }  @constraints);
+	return($self->relativise($path, $name, $mountpoint, $id3fs_path));
     }
     die("DB::filename: unhandled case\n"); #FIXME
 }
 
+sub relativise
+{
+    my($self, $path, $name, $mountpoint, $id3fs_path)=@_;
+    $id3fs_path=~s/(.*)\/.*/$1/;
+    my $rpath="$self->{absbase}/$path";
+    my $vpath="$mountpoint/$id3fs_path";
+    my @path=split(/\//,$rpath);
+    my @rel=split(/\//,$vpath);
+    #absolute paths have empty first element due to leading /
+    shift(@path) if($path[0] eq "");
+    shift(@rel)  if($rel[0]  eq "");
+    if($path[0] ne $rel[0])
+    {
+	#no path in common, return absolute
+	print "FAIL: NO PATHS IN COMMON\n";
+	return $name;
+    }
+    # f: /home/foo/bar/baz.mp3
+    # r: /home/ianb/music/albums
+    while(@path && @rel && ($path[0] eq $rel[0]))
+    {
+	shift(@path);
+	shift(@rel);
+	print "POP ";
+    }
+    print "\n";
+    my $upcount=scalar(@rel);
+    my $result="../" x $upcount;
+    $result .= join("/",@path);
+    $result .= "/$name";
+    return $result;
+}
+
 sub bare_tags
 {
     my($self)=@_;
diff --git a/lib/ID3FS/Fuse.pm b/lib/ID3FS/Fuse.pm
index 2a02276..bbf6f34 100644
--- a/lib/ID3FS/Fuse.pm
+++ b/lib/ID3FS/Fuse.pm
@@ -4,6 +4,7 @@ use strict;
 use warnings;
 use ID3FS::Path;
 use Fuse;
+use Cwd;
 use POSIX qw(EINVAL EROFS ENOENT EOPNOTSUPP S_IRUSR S_IRGRP S_IROTH S_IXUSR S_IXGRP S_IXOTH);
 our ($TYPE_DIR, $TYPE_SYMLINK)=(0040, 0120);
 
@@ -16,7 +17,7 @@ sub new
 
     $self->{db}=shift;
     $self->{source}=shift;
-    $self->{mountpoint}=shift;
+    $self->{mountpoint}=Cwd::abs_path(shift);
     $self->{debug}=shift;
     $self->{perms} = S_IRUSR() | S_IXUSR() | S_IRGRP() | S_IXGRP() | S_IROTH() | S_IXOTH();
 
@@ -83,7 +84,7 @@ sub readlink
 #    print "**READLINK: $filename\n";
     my $path=ID3FS::Path->new($self->{db}, $filename);
     return(-EINVAL()) unless($path->isfile());
-    return $path->dest();
+    return $path->dest($self->{mountpoint});
 }
 
 sub getdir
diff --git a/lib/ID3FS/Path.pm b/lib/ID3FS/Path.pm
index fdef5c3..25e4092 100644
--- a/lib/ID3FS/Path.pm
+++ b/lib/ID3FS/Path.pm
@@ -53,10 +53,10 @@ sub isvalid
 
 sub dest
 {
-    my($self)=@_;
+    my($self, $mountpoint)=@_;
     if($self->state() == $STATE_FILE)
     {
-	return $self->{db}->filename(@{$self->{elements}});
+	return $self->{db}->filename($mountpoint, @{$self->{elements}});
     }
     return "ERROR"; #should never happen?
 }
@@ -271,7 +271,6 @@ sub parse
 	{
 #	    print "SM: TRACKLIST: $name\n";
 	    my $track=ID3FS::PathElement::File->new($self->{db}, $name);
-	    push(@{$self->{elements}}, $track);
 	    if($track)
 	    {
 		push(@{$self->{elements}}, $track);
-- 
2.11.0