[pacman-dev] [PATCH 2/6] repo-add: fail early if repo can not be created

[Allan McRae]

Dan McGee wrote:
> On Thu, Feb 26, 2009 at 2:06 PM, Xavier Chantry <shiningxc at gmail.com> wrote:
>   
>> Before this commit, the repo creation could fail after all packages have
>> been added to the database. Now this will be detected before adding
>> anything.
>>
>> Signed-off-by: Xavier Chantry <shiningxc at gmail.com>
>> ---
>>  scripts/repo-add.sh.in |   18 +++++++++++++++---
>>  1 files changed, 15 insertions(+), 3 deletions(-)
>>
>> diff --git a/scripts/repo-add.sh.in b/scripts/repo-add.sh.in
>> index b12188c..a967506 100644
>> --- a/scripts/repo-add.sh.in
>> +++ b/scripts/repo-add.sh.in
>> @@ -326,9 +326,21 @@ for arg in "$@"; do
>>                        fi
>>                        msg "$(gettext "Extracting database to a temporary location...")"
>>                        bsdtar -xf "$REPO_DB_FILE" -C "$gstmpdir"
>> -               elif [ "$cmd" == "repo-remove" ]; then
>> -                       error "$(gettext "Repository file '%s' was not found.")" "$REPO_DB_FILE"
>> -                       exit 1
>> +               else
>> +                       case "$cmd" in
>> +                               repo-remove)
>> +                               error "$(gettext "Repository file '%s' was not found.")" "$REPO_DB_FILE"
>> +                               exit 1
>> +                               ;;
>> +                               repo-add)
>> +                               # check if the file can be created (write permission, directory existence, etc)
>> +                               if ! touch "$REPO_DB_FILE"; then
>> +                                       error "$(gettext "Repository file '%s' could not be created.")" "$REPO_DB_FILE"
>> +                                       exit 1
>> +                               fi
>> +                               rm -f "$REPO_DB_FILE"
>>     
> This seems scary to me- is there any reason to blow it away like this?
> It also makes the repo-add process non-atomic- someone could access
> the database and fail while you are adding 10 packages, correct?
>
>   

I thought about this too but I was less scared when I noticed that this 
is only done when the db file is not found.  So you are only removing 
the db file created in the touch statement.