[tepl] utils: replace_home_dir_with_tilde(): fix bug if $HOME ends with a slash

[Sébastien Wilmet <swilmet src gnome org>]

commit 8fc0eb83f96098a4ba83fda44d1b67e26153add0
Author: Sébastien Wilmet <sw swilmet be>
Date:   Mon Jan 11 15:11:51 2021 +0100

    utils: replace_home_dir_with_tilde(): fix bug if $HOME ends with a slash
    
    Fixes https://gitlab.gnome.org/GNOME/tepl/-/issues/19

 tepl/tepl-utils.c | 78 +++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 53 insertions(+), 25 deletions(-)
---
diff --git a/tepl/tepl-utils.c b/tepl/tepl-utils.c
index 480e888..d1add27 100644
--- a/tepl/tepl-utils.c
+++ b/tepl/tepl-utils.c
@@ -301,6 +301,40 @@ tepl_utils_get_file_shortname (const gchar *filename)
        return g_strndup (filename, get_extension_position (filename));
 }
 
+static gchar *
+get_home_dir_without_trailing_slash (void)
+{
+       const gchar *home_dir;
+       gchar *utf8_home_dir;
+       gsize length;
+
+       home_dir = g_get_home_dir ();
+       if (home_dir == NULL)
+       {
+               return NULL;
+       }
+
+       utf8_home_dir = g_filename_to_utf8 (home_dir, -1, NULL, NULL, NULL);
+       if (utf8_home_dir == NULL)
+       {
+               return NULL;
+       }
+
+       length = strlen (utf8_home_dir);
+       if (length == 0)
+       {
+               g_free (utf8_home_dir);
+               return NULL;
+       }
+
+       if (utf8_home_dir[length - 1] == '/')
+       {
+               utf8_home_dir[length - 1] = '\0';
+       }
+
+       return utf8_home_dir;
+}
+
 /**
  * tepl_utils_replace_home_dir_with_tilde:
  * @filename: the filename.
@@ -311,48 +345,42 @@ tepl_utils_get_file_shortname (const gchar *filename)
  * Returns: the new filename. Free with g_free().
  * Since: 4.4
  */
-/* This function comes from gedit. */
 gchar *
 tepl_utils_replace_home_dir_with_tilde (const gchar *filename)
 {
-       gchar *tmp;
-       gchar *home;
+       gchar *home_dir_without_trailing_slash;
+       gchar *home_dir_with_trailing_slash;
+       gchar *ret;
 
        g_return_val_if_fail (filename != NULL, NULL);
 
-       /* Note that g_get_home_dir returns a const string */
-       tmp = (gchar *) g_get_home_dir ();
-
-       if (tmp == NULL)
+       home_dir_without_trailing_slash = get_home_dir_without_trailing_slash ();
+       if (home_dir_without_trailing_slash == NULL)
        {
                return g_strdup (filename);
        }
 
-       home = g_filename_to_utf8 (tmp, -1, NULL, NULL, NULL);
-       if (home == NULL)
-       {
-               return g_strdup (filename);
-       }
+       home_dir_with_trailing_slash = g_strdup_printf ("%s/", home_dir_without_trailing_slash);
 
-       if (g_str_equal (filename, home))
+       if (g_str_equal (filename, home_dir_without_trailing_slash) ||
+           g_str_equal (filename, home_dir_with_trailing_slash))
        {
-               g_free (home);
-               return g_strdup ("~");
+               ret = g_strdup ("~");
+               goto out;
        }
 
-       tmp = home;
-       home = g_strdup_printf ("%s/", tmp);
-       g_free (tmp);
-
-       if (g_str_has_prefix (filename, home))
+       if (g_str_has_prefix (filename, home_dir_with_trailing_slash))
        {
-               gchar *res = g_strdup_printf ("~/%s", filename + strlen (home));
-               g_free (home);
-               return res;
+               ret = g_strdup_printf ("~/%s", filename + strlen (home_dir_with_trailing_slash));
+               goto out;
        }
 
-       g_free (home);
-       return g_strdup (filename);
+       ret = g_strdup (filename);
+
+out:
+       g_free (home_dir_without_trailing_slash);
+       g_free (home_dir_with_trailing_slash);
+       return ret;
 }
 
 static void