ui-shared: don't list branches when there is no repository

print_header() fills the branch switcher from the main ref store whenever
ctx.repo is set. For a request which prints a page before
prepare_repo_cmd() has cleared ctx.repo -- an unknown page name for a
repository whose repo.path is broken, for instance -- the ref store has
never been initialized, and get_main_ref_store() aborts after the
response has already begun:

    BUG: refs.c:2301: reference backend is unknown
    get_main_ref_store
    print_header at ui-shared.c:1057
    cgit_print_error_page(fmt="Invalid request")

Add cgit_have_repository() to say whether the repository for this request
was opened, and skip the switcher when it was not.

Signed-off-by: Saya Andy <saya.andy@posteo.com>

0 files changed, 0 insertions, 0 deletions