[PATCH] Improved submodule merge support

Currently merging submodules from a super module does not work at all, here is an example:

$ git merge change1
Updating 41dee71..6dbd2d9
Fast forward
 sub-module |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

$ git merge change2 fatal: cannot read object 4a0b570e9b7c6fd36f964eb6ef55263834462235 'sub-module' Merge with strategy recursive failed.

$ git status # On branch mergetest nothing to commit (working directory clean)

$ git submodule status
 4a0b570e9b7c6fd36f964eb6ef55263834462235 sub-module (undefined)

So - the merge simply failed, and git status has no clue what happened.

With the following patch, this happens instead:

$ git merge change1
Updating 41dee71..6dbd2d9
Fast forward
 sub-module |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

$ git merge change2 Auto-merged sub-module CONFLICT (submodule): Merge conflict in sub-module - needs b65e6131a2705620a0b08a4ecc44427b9059e4e3 Automatic merge failed; fix conflicts and then commit the result.

$ git status sub-module: needs merge # On branch mergetest # Changed but not updated: # (use "git add <file>..." to update what will be committed) # # unmerged: sub-module # no changes added to commit (use "git add" and/or "git commit -a")

$ git submodule status
 11253a619a520fa4b2e2c2f83cb5c897170faafd sub-module (undefined)
 4a0b570e9b7c6fd36f964eb6ef55263834462235 sub-module (undefined)
 b65e6131a2705620a0b08a4ecc44427b9059e4e3 sub-module (undefined)

To resolve this:

$ cd sub-module
$ git merge b65e6131a27
$ cd ..
$ git add sub-module
$ git commit -m 'merged sub-module blablabla'
$ git submodule status
 eb66300641185297648b2a71e41a66b2053fdae0 sub-module (undefined)

So it actually works in some sense, and you see what you need to merge aftwards in the submodule.

- Finn Arne

-- >8 -- Improved submodule merge support

When merging conflicting submodule changes from a supermodule, generate a conflict message saying what went wrong. Also leave the tree in a state where git status shows the conflict, and git submodule status gives the user enough information to do the merge manally. Previously this would just fail.

Signed-off-by: Finn Arne Gangstad <finnag@pvv.org>
---
 merge-recursive.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)