repo: Fix non-system remotes-config-dir usage

Before commit e0346c1, a non-system repo could specify
remotes-config-dir and have remotes read from there. However, adding
remotes would only be done in the config dir for a system repo. Restore
that by respecting remotes-config-dir when no sysroot is found and
adding back the ostree_repo_is_system() check when adding remotes.

Closes: #1133

Closes: #1151
Approved by: cgwalters

src/libostree/ostree-repo.c

@@ -1010,8 +1010,11 @@ impl_repo_remote_add (OstreeRepo     *self,
 
   remote = ostree_remote_new (name);
 
+  /* Only add repos in remotes.d for system repos since that was the
+   * legacy behavior and non-system repos would not expect it.
+   */
   g_autoptr(GFile) etc_ostree_remotes_d = get_remotes_d_dir (self, sysroot);
-  if (etc_ostree_remotes_d)
+  if (etc_ostree_remotes_d && ostree_repo_is_system (self))
     {
       g_autoptr(GError) local_error = NULL;
 
@@ -2040,10 +2043,6 @@ static GFile *
 get_remotes_d_dir (OstreeRepo          *self,
                    GFile               *sysroot)
 {
-  /* Support explicit override */
-  if (self->sysroot_dir != NULL && self->remotes_config_dir != NULL)
-    return g_file_resolve_relative_path (self->sysroot_dir, self->remotes_config_dir);
-
   g_autoptr(GFile) sysroot_owned = NULL;
   /* Very complicated sysroot logic; this bit breaks the otherwise mostly clean
    * layering between OstreeRepo and OstreeSysroot. First, If a sysroot was
@@ -2079,10 +2078,18 @@ get_remotes_d_dir (OstreeRepo          *self,
   if (sysroot == NULL && sysroot_ref == NULL)
     sysroot = self->sysroot_dir;
 
-  /* Did we find a sysroot? If not, NULL means use the repo config, otherwise
-   * return the path in /etc.
+  /* Was the config directory specified? If so, use that with the
+   * optional sysroot prepended. If not, return the path in /etc if the
+   * sysroot was found and NULL otherwise to use the repo config.
    */
-  if (sysroot == NULL)
+  if (self->remotes_config_dir != NULL)
+    {
+      if (sysroot == NULL)
+        return g_file_new_for_path (self->remotes_config_dir);
+      else
+        return g_file_resolve_relative_path (sysroot, self->remotes_config_dir);
+    }
+  else if (sysroot == NULL)
     return NULL;
   else
     return g_file_resolve_relative_path (sysroot, SYSCONF_REMOTES);