[Buildroot] [PATCH 2/6 v2] download/git: try to recover from utterly-broken repositories

[Yann E. MORIN <yann.morin.1998@free.fr>]

All,

On 2018-04-22 11:07 +0200, Yann E. MORIN spake thusly:
> In some cases, the repository may be in a state we can't automatically
> recover from, especially since we must still support oldish git versions
> that do not provide the necessary commands or options thereof.
> 
> As a last-ditch recovery, delete the repository and recreate the cache
> from scratch.

As Thomas noticed on IRC, this commit would remove the local git cache
in case the user enters an invalid changeset (typo in sha1 or tag name,
or whatnot).

A missing commit should not be considered as a broken repository,
especially since re-cloning from scratch would not help solve the
issue.

I already have a local change that will avoid trashing a git cache in
that case (using git rev-parse). I'll wait for some more reviews before
submitting again...

Regards,
Yann E. MORIN.

> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> Cc: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
> Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
> Cc: Ricardo Martincoski <ricardo.martincoski@gmail.com>
> Cc: Arnout Vandecappelle <arnout@mind.be>
> ---
>  support/download/git | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/support/download/git b/support/download/git
> index 19a3e8ebee..ebd04bc7b3 100755
> --- a/support/download/git
> +++ b/support/download/git
> @@ -16,6 +16,30 @@ set -e
>  # Environment:
>  #   GIT      : the git command to call
>  
> +# Save out path and options in case we need to call ourselves again
> +myname="${0}"
> +declare -a OPTS=("${@}")
> +
> +# This function is called when an error occurs. Its job is to attempt a
> +# clone from scratch (only once!) in case the git tree is borked, or in
> +# case an unexpected and unsupported situation arises with submodules
> +# or uncomitted stuff (e.g. if the user manually mucked around in the
> +# git cache).
> +_on_error() {
> +    local ret=${?}
> +
> +    if ${BR_GIT_BACKEND_FIRST_FAULT:-false}; then
> +        printf "Double-fault in git-cache"
> +        exit ${ret}
> +    fi
> +    export BR_GIT_BACKEND_FIRST_FAULT=true
> +
> +    popd >/dev/null
> +    rm -rf "${git_cache}"
> +
> +    exec "${myname}" "${OPTS[@]}" || exit ${ret}
> +}
> +
>  verbose=
>  recurse=0
>  while getopts "${BR_BACKEND_DL_GETOPTS}" OPT; do
> @@ -39,6 +63,9 @@ git_cache="${dl_dir}/git"
>  mkdir -p "${git_cache}"
>  pushd "${git_cache}" >/dev/null
>  
> +# Any error now should try to recover
> +trap _on_error ERR
> +
>  # Caller needs to single-quote its arguments to prevent them from
>  # being expanded a second time (in case there are spaces in them)
>  _git() {
> -- 
> 2.14.1
> 
> _______________________________________________
> buildroot mailing list
> buildroot at busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 223 225 172 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'