From 99986cab907709611c49f4f7c6b4dc07a6eda166 Mon Sep 17 00:00:00 2001
From: Philip Withnall <philip@tecnocode.co.uk>
Date: Tue, 24 Jun 2014 23:47:17 +0100
Subject: [PATCH] core: Correctly resolve symlinks when loading backends
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Instead of ignoring symlinks, we should resolve their targets, and
deduplicate after that. This fixes cases where folks is run in an
environment with software installed in loop mounted file systems — each
backend .so file in the backend path is actually a symlink to the proper
.so file in the loop mounted file system. This is the case on
Tinycorelinux. folks was previously not loading any backends in such an
environment because it ignored all symlinks.

Thanks to John Frankish for help in debugging this problem.
---
 folks/backend-store.vala | 43 +++++++++++++++++++++++++++++++++++++++----
 1 file changed, 39 insertions(+), 4 deletions(-)

diff --git a/folks/backend-store.vala b/folks/backend-store.vala
index e2ec287..8e20e89 100644
--- a/folks/backend-store.vala
+++ b/folks/backend-store.vala
@@ -632,6 +632,7 @@ public class Folks.BackendStore : Object {
           FileAttribute.STANDARD_NAME + "," +
           FileAttribute.STANDARD_TYPE + "," +
           FileAttribute.STANDARD_IS_SYMLINK + "," +
+          FileAttribute.STANDARD_SYMLINK_TARGET + "," +
           FileAttribute.STANDARD_CONTENT_TYPE;
 
       GLib.List<FileInfo> infos;
@@ -660,11 +661,45 @@ public class Folks.BackendStore : Object {
       foreach (var info in infos)
         {
           var file = dir.get_child (info.get_name ());
+
+          /* Handle symlinks by derefencing them. If we look at two symlinks
+           * with the same target, we don’t end up loading that backend twice
+           * due to hashing the backend’s absolute path in @modules_final.
+           *
+           * We can’t just ignore symlinks due to the way Tinycorelinux installs
+           * software: /usr/local/lib/folks/41/backends/bluez/bluez.so is a
+           * symlink to
+           * /tmp/tcloop/folks/usr/local/lib/folks/41/backends/bluez/bluez.so,
+           * a loopback squashfs mount of the folks file system. Ignoring
+           * symlinks means we would never load backends in that environment. */
+          if (info.get_is_symlink ())
+            {
+              debug ("Handling symlink ‘%s’ to ‘%s’.",
+                  file.get_path (), info.get_symlink_target ());
+
+              var old_file = file;
+              file = dir.resolve_relative_path (info.get_symlink_target ());
+
+              try
+                {
+                  info =
+                      yield file.query_info_async (attributes,
+                          FileQueryInfoFlags.NONE);
+                }
+              catch (Error error)
+                {
+                  /* Translators: the first parameter is a folder path and the second
+                   * is an error message. */
+                  warning (_("Error querying info for target ‘%s’ of symlink ‘%s’: %s"),
+                      file.get_path (), old_file.get_path (), error.message);
+
+                  continue;
+                }
+            }
+
+          /* Handle proper files. */
           var file_type = info.get_file_type ();
           unowned string content_type = info.get_content_type ();
-          /* don't load the library multiple times for its various symlink
-           * aliases */
-          var is_symlink = info.get_is_symlink ();
 
           string? mime = ContentType.get_mime_type (content_type);
 
@@ -679,7 +714,7 @@ public class Folks.BackendStore : Object {
                     }
                 }
             }
-          else if (mime == "application/x-sharedlib" && !is_symlink)
+          else if (mime == "application/x-sharedlib")
             {
               var path = file.get_path ();
               if (path != null)
-- 
1.9.0