Re: [PATCH 4/4] am: fix --interactive HEAD tree resolution
From: Johannes Schindelin <hidden>
Date: 2019-05-23 07:12:37
Hi Peff, On Mon, 20 May 2019, Jeff King wrote:
In interactive mode, "git am -i --resolved" will try to generate a patch based on what is in the index, so that it can prompt "apply this patch?". To do so it needs the tree of HEAD, which it tries to get with get_oid_tree(). However, this doesn't yield a tree oid; the "tree" part just means "if you must disambiguate short oids, then prefer trees" (and we do not need to disambiguate at all, since we are feeding a ref name). Instead, we must parse the oid as a commit (which should always be true in a non-corrupt repository), and access its tree pointer manually. This has been broken since the conversion to C in 7ff2683253 (builtin-am: implement -i/--interactive, 2015-08-04), but there was no test coverage because of interactive-mode's insistence on having a tty. That was lifted in the previous commit, so we can now add a test for this case. Note that before this patch, the test would result in a BUG() which comes from 3506dc9445 (has_uncommitted_changes(): fall back to empty tree, 2018-07-11). But before that, we'd have simply segfaulted (and in fact this is the exact type of case the BUG() added there was trying to catch!).
What an old breakage! Thanks for analyzing and fixing it.
quoted hunk ↗ jump to hunk
diff --git a/builtin/am.c b/builtin/am.c index ea16b844f1..33bd7a6eab 100644 --- a/builtin/am.c +++ b/builtin/am.c@@ -1339,9 +1339,17 @@ static void write_index_patch(const struct am_state *state) struct rev_info rev_info; FILE *fp; - if (!get_oid_tree("HEAD", &head)) - tree = lookup_tree(the_repository, &head); - else + if (!get_oid("HEAD", &head)) { + struct object *obj; + struct commit *commit; + + obj = parse_object_or_die(&head, NULL); + commit = object_as_type(the_repository, obj, OBJ_COMMIT, 0); + if (!commit) + die("unable to parse HEAD as a commit");
Wouldn't this be easier to read like this: struct commit *commit = lookup_commit_reference(the_repository, &head);
quoted hunk ↗ jump to hunk
+ + tree = get_commit_tree(commit); + } else tree = lookup_tree(the_repository, the_repository->hash_algo->empty_tree);diff --git a/t/t4257-am-interactive.sh b/t/t4257-am-interactive.sh new file mode 100755 index 0000000000..6989bf7aba --- /dev/null +++ b/t/t4257-am-interactive.sh@@ -0,0 +1,49 @@ +#!/bin/sh + +test_description='am --interactive tests' +. ./test-lib.sh + +test_expect_success 'set up patches to apply' ' + test_commit unrelated && + test_commit no-conflict && + test_commit conflict-patch file patch && + git format-patch --stdout -2 >mbox && + + git reset --hard unrelated && + test_commit conflict-master file master base +' + +# Sanity check our setup. +test_expect_success 'applying all patches generates conflict' ' + test_must_fail git am mbox && + echo resolved >file && + git add -u && + git am --resolved +' + +test_expect_success 'interactive am can apply a single patch' ' + git reset --hard base && + printf "%s\n" y n | git am -i mbox &&
Since we want contributors to copy-edit our test cases (even if they do not happen to be Unix shell scripting experts), it would be better to write test_write_lines y n | git am -i mbox && here. Same for similar `printf` invocations further down.
+ + echo no-conflict >expect && + git log -1 --format=%s >actual && + test_cmp expect actual
I would prefer
test no-conflict = "$(git show -s --format=%s HEAD)"
or even better:
test_cmp_head_oneline () {
if test "$1" != "$(git show -s --format=%s HEAD)"
then
echo >&4 "HEAD's oneline is '$(git show -s \
--format=%s HEAD)'; expected '$1'"
return 1
fi
}
+' + +test_expect_success 'interactive am can resolve conflict' ' + git reset --hard base && + printf "%s\n" y y | test_must_fail git am -i mbox && + echo resolved >file && + git add -u && + printf "%s\n" v y | git am -i --resolved &&
Maybe a comment, to explain to the casual reader what the "v" and the "y" are supposed to do?
+ + echo conflict-patch >expect && + git log -1 --format=%s >actual && + test_cmp expect actual && + + echo resolved >expect && + git cat-file blob HEAD:file >actual && + test_cmp expect actual +'
After wrapping my head around the intentions of these commands, I agree that they test for the right thing. Thanks! Dscho
+ +test_done -- 2.22.0.rc1.539.g7bfcdfe86d