# Generally, the steps to update the vendored repo are:
1. Run the section to prepare the repo, with our current patch-stack.
2. Run the section to vendor the current version of the repo to verify
   there have been no Mozilla changes since the last vendoring.  If
   there have been no Mozilla changes, there will be only one modified
   file (README.mozilla.last-vendor).  If there are other modified
   files:
   - Note the commit shas modifying the repo.
   - Run the section on extracting a Mozilla commit to update the
     patch-stack.
   - Run the section to save the patch-stack as a separate commit.
   - Re-vendor to verify the single changed file.
3. Rebase the patch stack onto a new git commit from upstream.
4. Run the section to vendor the new version of the repo.
5. Run the section to save the newly vendored files.
6. Run the section to save the patch-stack and amend it with the
   current commit.
7. If newly vendored code modifies any BUILD.gn files, run the section
   to regenerate moz.build files.


# the commands in the following sections should be run in a bash shell
# from the top of the mozilla repository (i.e. @TOPSRCDIR@)
# additionally, exporting these variables is required for all sections
export EXT_REPO_LOCATION=.moz-vendoring
export REPO_PATH="$EXT_REPO_LOCATION/abseil-cpp"
export REPO_URL="https://chromium.googlesource.com/chromium/src/third_party"
export DEST_PATH="`pwd`/third_party/abseil-cpp"
export BASE_COMMIT_FILE="$DEST_PATH/README.mozilla.last-vendor"


# prepare abseil repo
mkdir -p $EXT_REPO_LOCATION
git clone $REPO_URL $REPO_PATH
( cd $REPO_PATH \
  && git checkout -b mozpatches `tail -1 $BASE_COMMIT_FILE` \
  && git am $DEST_PATH/moz-patch-stack/* \
)


# vendor abseil-cpp
./mach python dom/media/webrtc/third_party_build/vendor-libwebrtc.py \
    --from-local $REPO_PATH \
    --commit mozpatches abseil-cpp \
&& rm -rf $DEST_PATH/absl/time/internal/cctz/testdata \
&& (hg revert --include "**/moz.build" &> /dev/null) \
&& ( cd $REPO_PATH \
     && echo "# base of lastest vendoring" >> $BASE_COMMIT_FILE \
     && git rev-parse --short `git merge-base mozpatches main` >> $BASE_COMMIT_FILE \
   )


# to save the newly vendored files
hg status -nd | xargs hg rm
hg status -nu | xargs hg add
( NEW_BASE_SHA=`tail -1 $BASE_COMMIT_FILE` ; \
  hg commit -m "Bug xxx - vendor abseil-cpp from libwebrtc/third_party $NEW_BASE_SHA" )


# to save the patch-stack as a separate commit
./mach python dom/media/webrtc/third_party_build/save_patch_stack.py \
  --state-path "" \
  --repo-path $REPO_PATH \
  --branch mozpatches \
  --target-branch-head `tail -1 $BASE_COMMIT_FILE` \
  --patch-path $DEST_PATH/moz-patch-stack \
  --skip-startup-sanity \
  --separate-commit-bug-number 1234


# to save the patch-stack and amend it with the current commit
./mach python dom/media/webrtc/third_party_build/save_patch_stack.py \
  --state-path "" \
  --repo-path $REPO_PATH \
  --branch mozpatches \
  --target-branch-head `tail -1 $BASE_COMMIT_FILE` \
  --patch-path $DEST_PATH/moz-patch-stack \
  --skip-startup-sanity


# to regenerate moz.build files
./mach python build/gn_processor.py \
  dom/media/webrtc/third_party_build/gn-configs/abseil.json
hg status -nd | xargs hg rm
hg status -nu | xargs hg add
hg commit -m "Bug xxx - generated moz.build files"


# to extract a Mozilla commit and apply it to the git patch-stack
./mach python dom/media/webrtc/third_party_build/extract-for-git.py \
  --target abseil-cpp {commit-sha}
mv mailbox.patch $REPO_PATH
( cd $REPO_PATH \
  && git am mailbox.patch \
)