| Message ID | 20190322093138.13765-5-pclouds@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | prevent 'checkout -m' from losing staged changes | expand |
On Fri, Mar 22, 2019 at 2:32 AM Nguyễn Thái Ngọc Duy <pclouds@gmail.com> wrote: > > When --merge is specified, we may need to do a real merge (instead of > three-way tree unpacking), the steps are best seen in git-checkout.sh > version before it's removed: > > # Match the index to the working tree, and do a three-way. > git diff-files --name-only | git update-index --remove --stdin && > work=`git write-tree` && > git read-tree $v --reset -u $new || exit > > git merge-recursive $old -- $new $work > > # Do not register the cleanly merged paths in the index yet. > # this is not a real merge before committing, but just carrying > # the working tree changes along. > unmerged=`git ls-files -u` > git read-tree $v --reset $new > case "$unmerged" in > '') ;; > *) > ( > z40=0000000000000000000000000000000000000000 > echo "$unmerged" | > sed -e 's/^[0-7]* [0-9a-f]* /'"0 $z40 /" > echo "$unmerged" > ) | git update-index --index-info > ;; > esac > > Notice the last 'read-tree --reset' step. We restore worktree back to > 'new' tree after worktree's messed up by merge-recursive. If there are > staged changes before this whole command sequence is executed, they > are lost because they are unlikely part of the 'new' tree to be > restored. > > There is no easy way to fix this. Elijah may have something up his > sleeves [1], but until then, check if there are staged changes and > refuse to run and lose them. The user would need to do "git reset" to > continue in this case. > > A note about the test update. 'checkout -m' in that test will fail > because a deletion is staged. This 'checkout -m' was previously needed > to verify quietness behavior of unpack-trees. But a different check > has been put in place in the last patch. We can safely drop > 'checkout -m' now. > > [1] CABPp-BFoL_U=bzON4SEMaQSKU2TKwnOgNqjt5MUaOejTKGUJxw@mail.gmail.com > > Reported-by: Phillip Wood <phillip.wood@dunelm.org.uk> > Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> > --- > builtin/checkout.c | 11 ++++++++++- > t/t7201-co.sh | 10 +--------- > 2 files changed, 11 insertions(+), 10 deletions(-) > > diff --git a/builtin/checkout.c b/builtin/checkout.c > index 22fb6c0cae..7cd01f62be 100644 > --- a/builtin/checkout.c > +++ b/builtin/checkout.c > @@ -725,7 +725,10 @@ static int merge_working_tree(const struct checkout_opts *opts, > */ > struct tree *result; > struct tree *work; > + struct tree *old_tree; > struct merge_options o; > + struct strbuf sb = STRBUF_INIT; > + > if (!opts->merge) > return 1; > > @@ -735,6 +738,12 @@ static int merge_working_tree(const struct checkout_opts *opts, > */ > if (!old_branch_info->commit) > return 1; > + old_tree = get_commit_tree(old_branch_info->commit); > + > + if (repo_index_has_changes(the_repository, old_tree, &sb)) > + die(_("cannot continue with staged changes in " > + "the following files:\n%s"), sb.buf); > + strbuf_release(&sb); > > /* Do more real merge */ > > @@ -772,7 +781,7 @@ static int merge_working_tree(const struct checkout_opts *opts, > ret = merge_trees(&o, > get_commit_tree(new_branch_info->commit), > work, > - get_commit_tree(old_branch_info->commit), > + old_tree, > &result); > if (ret < 0) > exit(128); > diff --git a/t/t7201-co.sh b/t/t7201-co.sh > index f165582019..5990299fc9 100755 > --- a/t/t7201-co.sh > +++ b/t/t7201-co.sh > @@ -224,15 +224,7 @@ test_expect_success 'switch to another branch while carrying a deletion' ' > test_i18ngrep overwritten errs && > > test_must_fail git read-tree --quiet -m -u HEAD simple 2>errs && > - test_must_be_empty errs && > - > - git checkout --merge simple 2>errs && > - test_i18ngrep ! overwritten errs && > - git ls-files -u && > - test_must_fail git cat-file -t :0:two && > - test "$(git cat-file -t :1:two)" = blob && > - test "$(git cat-file -t :2:two)" = blob && > - test_must_fail git cat-file -t :3:two > + test_must_be_empty errs > ' Ah, I see you avoid the other bug in checkout by just removing its usage. Seems fair enough; I can add a separate test to demonstrate that bug when I get some time to work on it. Hopefully I'll find a quick fix too.
diff --git a/builtin/checkout.c b/builtin/checkout.c index 22fb6c0cae..7cd01f62be 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -725,7 +725,10 @@ static int merge_working_tree(const struct checkout_opts *opts, */ struct tree *result; struct tree *work; + struct tree *old_tree; struct merge_options o; + struct strbuf sb = STRBUF_INIT; + if (!opts->merge) return 1; @@ -735,6 +738,12 @@ static int merge_working_tree(const struct checkout_opts *opts, */ if (!old_branch_info->commit) return 1; + old_tree = get_commit_tree(old_branch_info->commit); + + if (repo_index_has_changes(the_repository, old_tree, &sb)) + die(_("cannot continue with staged changes in " + "the following files:\n%s"), sb.buf); + strbuf_release(&sb); /* Do more real merge */ @@ -772,7 +781,7 @@ static int merge_working_tree(const struct checkout_opts *opts, ret = merge_trees(&o, get_commit_tree(new_branch_info->commit), work, - get_commit_tree(old_branch_info->commit), + old_tree, &result); if (ret < 0) exit(128); diff --git a/t/t7201-co.sh b/t/t7201-co.sh index f165582019..5990299fc9 100755 --- a/t/t7201-co.sh +++ b/t/t7201-co.sh @@ -224,15 +224,7 @@ test_expect_success 'switch to another branch while carrying a deletion' ' test_i18ngrep overwritten errs && test_must_fail git read-tree --quiet -m -u HEAD simple 2>errs && - test_must_be_empty errs && - - git checkout --merge simple 2>errs && - test_i18ngrep ! overwritten errs && - git ls-files -u && - test_must_fail git cat-file -t :0:two && - test "$(git cat-file -t :1:two)" = blob && - test "$(git cat-file -t :2:two)" = blob && - test_must_fail git cat-file -t :3:two + test_must_be_empty errs ' test_expect_success 'checkout to detach HEAD (with advice declined)' '
When --merge is specified, we may need to do a real merge (instead of three-way tree unpacking), the steps are best seen in git-checkout.sh version before it's removed: # Match the index to the working tree, and do a three-way. git diff-files --name-only | git update-index --remove --stdin && work=`git write-tree` && git read-tree $v --reset -u $new || exit git merge-recursive $old -- $new $work # Do not register the cleanly merged paths in the index yet. # this is not a real merge before committing, but just carrying # the working tree changes along. unmerged=`git ls-files -u` git read-tree $v --reset $new case "$unmerged" in '') ;; *) ( z40=0000000000000000000000000000000000000000 echo "$unmerged" | sed -e 's/^[0-7]* [0-9a-f]* /'"0 $z40 /" echo "$unmerged" ) | git update-index --index-info ;; esac Notice the last 'read-tree --reset' step. We restore worktree back to 'new' tree after worktree's messed up by merge-recursive. If there are staged changes before this whole command sequence is executed, they are lost because they are unlikely part of the 'new' tree to be restored. There is no easy way to fix this. Elijah may have something up his sleeves [1], but until then, check if there are staged changes and refuse to run and lose them. The user would need to do "git reset" to continue in this case. A note about the test update. 'checkout -m' in that test will fail because a deletion is staged. This 'checkout -m' was previously needed to verify quietness behavior of unpack-trees. But a different check has been put in place in the last patch. We can safely drop 'checkout -m' now. [1] CABPp-BFoL_U=bzON4SEMaQSKU2TKwnOgNqjt5MUaOejTKGUJxw@mail.gmail.com Reported-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> --- builtin/checkout.c | 11 ++++++++++- t/t7201-co.sh | 10 +--------- 2 files changed, 11 insertions(+), 10 deletions(-)