When attempting to merge in a superproject with conflicting submodule
pointers that cannot be fast-forwarded or trivially resolved, the merge
fails and Git prints an error message that accurately describes the
failure, but does not provide steps for the user to resolve the error.
Git is left in a conflicted state, which requires the user to:
1. merge submodules or update submodules to an already existing
commit that reflects the merge
2. add submodules changes to the superproject
3. finish merging superproject
These steps are non-obvious for newer submodule users to figure out
based on the error message and neither `git submodule status` nor `git
status` provide any useful pointers.
Update error message to provide steps to resolve submodule merge
conflict. Future work could involve adding an advice flag to the
message. Although the message is long, it also has the id of the
submodule commit that needs to be merged, which could be useful
information for the user.
Additionally, 5 merge failures that resulted in an early return have
been updated to reflect the status of the merge.
1. Null merge base (null o): CONFLICT_SUBMODULE_NULL_MERGE_BASE added
as a new conflict type and will print updated error message.
2. Null merge side a (null a): BUG(). See [1] for discussion
3. Null merge side b (null b): BUG(). See [1] for discussion
4. Submodule not checked out: added NEEDSWORK bit
5. Submodule commits not present: added NEEDSWORK bit
The errors with a NEEDSWORK bit deserve a more detailed explanation of
how to resolve them. See [2] for more context.
[1] https://lore.kernel.org/git/CABPp-BE0qGwUy80dmVszkJQ+tcpfLRW0OZyErymzhZ9+HWY1mw@mail.gmail.com/
[2] https://lore.kernel.org/git/xmqqpmhjjwo9.fsf@gitster.g/
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Earlier, a230949 (am --rebasing: get patch body from commit, not
from mailbox, 2012-06-26) learned to regenerate patch body from the
commit object while rebasing, instead of reading from the rebase-am
front-end. While doing so, it used "git diff-tree" but without
giving it the "--full-index" option.
This does not matter for in-repository objects; during rebasing, any
abbreviated object name should uniquely identify them.
But we may be rebasing a commit that contains a change to a gitlink,
in which case we usually should not have the object (it names a
commit in the submodule). A full object name is necessary to later
reconstruct a fake ancestor index for them.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch changes every occurrence of "! git" -- with the meaning
that a git call has to gracefully fail -- into "test_must_fail git".
This is useful to
- make sure the test does not fail because of a signal,
e.g. SIGSEGV, and
- advertise the use of "test_must_fail" for new tests.
Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When rebasing or stashing, chances are that you do not care about
dirty submodules, since they are not updated by those actions anyway.
So ignore the submodules' states.
Note: the submodule states -- as committed in the superproject --
will still be stashed and rebased, it is _just_ the state of the
submodule in the working tree which is ignored.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
