How to apply a patch made by repo diff?

[Chih-Wei]

Hi,
The repo diff generated a patch like

project external/e2fsprogs/
diff --git a/Android.mk b/Android.mk
...

However, there is no easy way to apply it.
One has to cd to the project directory to use git apply command.
Am I correct?

Is there a plan to add 'repo apply' command which
will automatically apply the specific patch to appropriate projects?

[Shawn Pearce]

On Sun, Apr 26, 2009 at 19:49, Chih-Wei <cwh...@linux.org.tw> wrote:

The repo diff generated a patch like

project external/e2fsprogs/
diff --git a/Android.mk b/Android.mk
...

However, there is no easy way to apply it.
One has to cd to the project directory to use git apply command.
Am I correct?

Sadly, yes.  Its worse when multiple projects are listed as then you need to split the patch file by hand.

repo diff was never intended for use in a "diff | apply" sort of pipeline.  It was written really quickly as a way to help a user see what is unmodified in their client prior to commit.  I agree it isn't suited for this purpose.  If we are seriously going to support the idea of patches from "repo diff" being able to be applied later then we should also support more options to repo diff, like git diff supports, so you can obtain different views.

Is there a plan to add 'repo apply' command which
will automatically apply the specific patch to appropriate projects?

No, but if someone proposes change(s) on review.source.android.com to implement a "repo apply" subcommand, I'll review it, and if it does what it claims to do, I'll include it in the next build of repo.

So.  Answer is, yes, we can have a repo apply, but its not critical to me, so I won't write it myself.

[Chih-Wei]

On 4月27日, 下午10時17分, Shawn Pearce <s...@google.com> wrote:

> On Sun, Apr 26, 2009 at 19:49, Chih-Wei <cwhu...@linux.org.tw> wrote:
> > However, there is no easy way to apply it.
> > One has to cd to the project directory to use git apply command.
> > Am I correct?
>
> Sadly, yes. Its worse when multiple projects are listed as then you need to
> split the patch file by hand.

Yes, exactly.

> So. Answer is, yes, we can have a repo apply, but its not critical to me,
> so I won't write it myself.

However, people do post patches made by repo diff,
and others do ask how to use them. For example,
http://groups.google.com/group/android-porting/browse_thread/thread/cf10679160e948a5/5f251a2b8051d66d?hl=zh-TW&lnk=gst&q=patch#5f251a2b8051d66d

Unfortunately I'm not familiar with python, or I may try to help.

Just curious. How do the core team apply patches from contributors?
Do you also split a patch containing multiple projects by hand?
(or you won't accept such a patch at all?)

[Jean-Baptiste Queru]

The Android team doesn't accept patches, we only accept commits
uploaded to Gerrit through repo upload.

JBQ

2009/4/28 Chih-Wei <cwh...@linux.org.tw>:

--
Jean-Baptiste M. "JBQ" Queru
Android Engineer, Google.

Questions sent directly to me that have no reason for being private
will likely get ignored or forwarded to a public forum with no further
warning.

[Elvis Dowson]

I think a repo apply command is really necessary. Imagine my surprise
today, when I sent a patch to a colleague working on an android port
and we discovered that the output of the repo diff cannot be used
directly, without splitting up the patches and using git apply. Really
tedious. Most of the changes are not stuff that we can submit to the
gerrit system, since it's specific modifications and adaptations for a
specific target hardware :-)

Elvis Dowson

[Kapil]

Consider

## Script to patch up diff reated by `repo diff`

if [ -z "$1" ] || [ ! -e "$1" ]; then
    echo "Usages: $0 <repo_diff_file>";
    exit 0;
fi

rm -fr _tmp_splits*
cat $1 | csplit -qf '' -b "_tmp_splits.%d.diff" - '/^project.*\/$/' '{*}'

working_dir=`pwd`

for proj_diff in `ls _tmp_splits.*.diff`
do
    chg_dir=`cat $proj_diff | grep '^project.*\/$' | cut -d " " -f 2`
    echo "FILE: $proj_diff $chg_dir"
    if [ -e $chg_dir ]; then
        ( cd $chg_dir; \
            cat $working_dir/$proj_diff | grep -v '^project.*\/$' | patch -Np1;);
    else
        echo "$0: Project directory $chg_dir don't exists.";
    fi
done