install --from: Try to reuse existing remotes

We don't really need to create an origin remote if the same
uri is already there for an enumeratable remote, we can
just reuse that. Having multiple remotes for a single
repository just means we'll be downloading the summary file
multiple times.

common/flatpak-dir.c

@@ -5764,16 +5764,55 @@ flatpak_dir_create_remote_for_ref_file (FlatpakDir *self,
       return FALSE;
     }
 
-  remote = flatpak_dir_create_origin_remote (self, url, name, title, ref,
-                                             gpg_data, NULL, error);
+  /* First try to reuse existing remote */
+  remote = flatpak_dir_find_remote_by_uri (self, url);
+
   if (remote == NULL)
-    return FALSE;
+    {
+      remote = flatpak_dir_create_origin_remote (self, url, name, title, ref,
+                                                 gpg_data, NULL, error);
+      if (remote == NULL)
+        return FALSE;
+    }
 
   *remote_name_out = g_steal_pointer (&remote);
   *ref_out = (char *)g_steal_pointer (&ref);
   return TRUE;
 }
 
+char *
+flatpak_dir_find_remote_by_uri (FlatpakDir   *self,
+                                const char   *uri)
+{
+  g_auto(GStrv) remotes = NULL;
+
+  if (!flatpak_dir_ensure_repo (self, NULL, NULL))
+    return NULL;
+
+  remotes = flatpak_dir_list_enumerated_remotes (self, NULL, NULL);
+  if (remotes)
+    {
+      int i;
+
+      for (i = 0; remotes != NULL && remotes[i] != NULL; i++)
+        {
+          const char *remote = remotes[i];
+          g_autofree char *remote_uri = NULL;
+
+          if (!ostree_repo_remote_get_url (self->repo,
+                                           remote,
+                                           &remote_uri,
+                                           NULL))
+            continue;
+
+          if (strcmp (uri, remote_uri) == 0)
+            return g_strdup (remote);
+        }
+    }
+
+  return NULL;
+}
+
 char **
 flatpak_dir_list_remotes (FlatpakDir   *self,
                           GCancellable *cancellable,

common/flatpak-dir.h

@@ -424,6 +424,8 @@ gboolean   flatpak_dir_create_remote_for_ref_file (FlatpakDir   *self,
                                                    char   **ref_out,
                                                    GError **error);
 
+char      *flatpak_dir_find_remote_by_uri (FlatpakDir   *self,
+                                           const char   *uri);
 char     **flatpak_dir_list_remotes (FlatpakDir   *self,
                                      GCancellable *cancellable,
                                      GError      **error);