@matheusbsbs / matheus-bagliano / commits / 7adf526670

merge: check config before loading commits

Now that we use generation numbers from the commit-graph, we must ensure that all commits that exist in the commit-graph are loaded from that file instead of from the object database. Since the commit-graph file is only checked if core.commitGraph is true, we must check the default config before we load any commits. In the merge builtin, the config was checked after loading the HEAD commit. This was due to the use of the global 'branch' when checking merge-specific config settings. Move the config load to be between the initialization of 'branch' and the commit lookup. Without this change, a fast-forward merge would hit a BUG("bad generation skip") statement in commit.c during paint_down_to_common(). This is because the HEAD commit would be loaded with "infinite" generation but then reached by commits with "finite" generation numbers. Add a test to t5318-commit-graph.sh that exercises this code path to prevent a regression. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Derrick Stolee committed May 1, 2018 at 12:47 UTC 7adf526670c5c050ddc22ddcf2fdc7bd654f8fc5

2 files changed +13 -3

builtin/merge.c

+4 -3

@@ -1148,14 +1148,15 @@ int cmd_merge(int argc, const char **argv, const char *prefix)

1148 branch = branch_to_free = resolve_refdup("HEAD", 0, &head_oid, NULL);

1149 if (branch)

1150 skip_prefix(branch, "refs/heads/", &branch);

1151 +

1152 + init_diff_ui_defaults();

1153 + git_config(git_merge_config, NULL);

1154 +

1155 if (!branch || is_null_oid(&head_oid))

1156 head_commit = NULL;

1157 else

1158 head_commit = lookup_commit_or_die(&head_oid, "HEAD");

1159

1156 - init_diff_ui_defaults();

1157 - git_config(git_merge_config, NULL);

1158 -

1160 if (branch_mergeoptions)

1161 parse_branch_merge_options(branch_mergeoptions);

1162 argc = parse_options(argc, argv, prefix, builtin_merge_options,

t/t5318-commit-graph.sh

@@ -221,4 +221,13 @@ test_expect_success 'write graph in bare repo' '

221 graph_git_behavior 'bare repo with graph, commit 8 vs merge 1' bare commits/8 merge/1

222 graph_git_behavior 'bare repo with graph, commit 8 vs merge 2' bare commits/8 merge/2

223

224 +test_expect_success 'perform fast-forward merge in full repo' '

225 + cd "$TRASH_DIRECTORY/full" &&

226 + git checkout -b merge-5-to-8 commits/5 &&

227 + git merge commits/8 &&

228 + git show-ref -s merge-5-to-8 >output &&

229 + git show-ref -s commits/8 >expect &&

230 + test_cmp expect output

231 +'

232 +

233 test_done