[rhythmbox] lib: add rb_file_resolve_symlink

[Jonathan Matthew <jmatthew src gnome org>]

commit fba05e5b19e505047b66a8f6d1aa9854cb50dabb
Author: Jonathan Matthew <jonathan d14n org>
Date:   Sat May 24 16:36:09 2014 +1000

    lib: add rb_file_resolve_symlink
    
    Like rb_uri_resolve_symlink, but taking and returning a GFile rather than
    a uri string

 lib/rb-file-helpers.c |   72 ++++++++++++++++++++++++++++++++++--------------
 lib/rb-file-helpers.h |    1 +
 2 files changed, 52 insertions(+), 21 deletions(-)
---
diff --git a/lib/rb-file-helpers.c b/lib/rb-file-helpers.c
index aef521e..68eefb6 100644
--- a/lib/rb-file-helpers.c
+++ b/lib/rb-file-helpers.c
@@ -347,44 +347,76 @@ rb_file_helpers_shutdown (void)
 char *
 rb_uri_resolve_symlink (const char *uri, GError **error)
 {
-       GFile *file = NULL;
+       GFile *file;
+       GFile *rfile;
+       char *result = NULL;
+
+       file = g_file_new_for_uri (uri);
+       rfile = rb_file_resolve_symlink (file, error);
+       g_object_unref (file);
+
+       if (rfile != NULL) {
+               result = g_file_get_uri (rfile);
+               g_object_unref (rfile);
+       }
+       return result;
+}
+
+/**
+ * rb_file_resolve_symlink:
+ * @file: the file to process
+ * @error: returns error information
+ *
+ * Attempts to resolve symlinks leading to @file and return a canonical location.
+ *
+ * Return value: a #GFile representing the canonical location, or NULL on error
+ */
+GFile *
+rb_file_resolve_symlink (GFile *file, GError **error)
+{
        GFileInfo *file_info = NULL;
        int link_count = 0;
-       char *result = NULL;
+       GFile *result = NULL;
+       GFile *current;
+       char *furi;
+       char *ruri;
        const char *attr = G_FILE_ATTRIBUTE_STANDARD_SYMLINK_TARGET;
        GError *l_error = NULL;
-       
-       file = g_file_new_for_uri (uri);
 
+       current = g_object_ref (file);
        while (link_count < MAX_LINK_LEVEL) {
                GFile *parent;
                GFile *new_file;
                const char *target;
 
                /* look for a symlink target */
-               file_info = g_file_query_info (file,
+               file_info = g_file_query_info (current,
                                               attr,
                                               G_FILE_QUERY_INFO_NONE,
                                               NULL, &l_error);
                if (l_error != NULL) {
                        /* argh */
-                       result = g_file_get_uri (file);
-                       rb_debug ("error querying %s: %s", result, l_error->message);
-                       g_free (result);
+                       ruri = g_file_get_uri (current);
+                       rb_debug ("error querying %s: %s", ruri, l_error->message);
+                       g_free (ruri);
                        result = NULL;
                        break;
                } else if (g_file_info_has_attribute (file_info, attr) == FALSE) {
                        /* no symlink, so return the path */
-                       result = g_file_get_uri (file);
+                       result = g_object_ref (current);
                        if (link_count > 0) {
-                               rb_debug ("resolved symlinks: %s -> %s", uri, result);
+                               furi = g_file_get_uri (file);
+                               ruri = g_file_get_uri (result);
+                               rb_debug ("resolved symlinks: %s -> %s", furi, ruri);
+                               g_free (furi);
+                               g_free (ruri);
                        }
                        break;
                }
 
                /* resolve it and try again */
                new_file = NULL;
-               parent = g_file_get_parent (file);
+               parent = g_file_get_parent (current);
                if (parent == NULL) {
                        /* dang */
                        break;
@@ -397,10 +429,10 @@ rb_uri_resolve_symlink (const char *uri, GError **error)
                g_object_unref (file_info);
                file_info = NULL;
 
-               g_object_unref (file);
-               file = new_file;
+               g_object_unref (current);
+               current = new_file;
 
-               if (file == NULL) {
+               if (current == NULL) {
                        /* dang */
                        break;
                }
@@ -408,14 +440,12 @@ rb_uri_resolve_symlink (const char *uri, GError **error)
                link_count++;
        }
 
-       if (file != NULL) {
-               g_object_unref (file);
-       }
-       if (file_info != NULL) {
-               g_object_unref (file_info);
-       }
+       g_clear_object (&current);
+       g_clear_object (&file_info);
        if (result == NULL && error == NULL) {
-               rb_debug ("too many symlinks while resolving %s", uri);
+               furi = g_file_get_uri (file);
+               rb_debug ("too many symlinks while resolving %s", furi);
+               g_free (furi);
                l_error = g_error_new (G_IO_ERROR,
                                       G_IO_ERROR_TOO_MANY_LINKS,
                                       _("Too many symlinks"));
diff --git a/lib/rb-file-helpers.h b/lib/rb-file-helpers.h
index 4fef68b..cea76f3 100644
--- a/lib/rb-file-helpers.h
+++ b/lib/rb-file-helpers.h
@@ -50,6 +50,7 @@ gboolean      rb_uri_mkstemp          (const char *prefix, char **uri_ret,
                                         GOutputStream **stream, GError **error);
 
 char *         rb_uri_resolve_symlink  (const char *uri, GError **error);
+GFile *                rb_file_resolve_symlink (GFile *file, GError **error);
 gboolean       rb_uri_is_directory     (const char *uri);
 gboolean       rb_uri_exists           (const char *uri);
 gboolean       rb_uri_is_readable      (const char *uri);