commit-graph: when incompatible with graphs, indicate why

When `gc.writeCommitGraph = true`, it is possible that the commit-graph is _still_ not written: replace objects, grafts and shallow repositories are incompatible with the commit-graph feature. Under such circumstances, we need to indicate to the user why the commit-graph was not written instead of staying silent about it. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Acked-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed Feb 11, 2021 at 15:39 UTC c85eec7fc37e1ca79072f263ae6ea1ee305ba38c
1 file changed +11 -3
commit-graph.c
+11 -3
@@ -205,16 +205,24 @@ static int commit_graph_compatible(struct repository *r)
205
206 if (read_replace_refs) {
207 prepare_replace_object(r);
208 - if (hashmap_get_size(&r->objects->replace_map->map))
208 + if (hashmap_get_size(&r->objects->replace_map->map)) {
209 + warning(_("repository contains replace objects; "
210 + "skipping commit-graph"));
211 return 0;
212 + }
213 }
214
215 prepare_commit_graft(r);
216 if (r->parsed_objects &&
214 - (r->parsed_objects->grafts_nr || r->parsed_objects->substituted_parent))
217 + (r->parsed_objects->grafts_nr || r->parsed_objects->substituted_parent)) {
218 + warning(_("repository contains (deprecated) grafts; "
219 + "skipping commit-graph"));
220 return 0;
216 - if (is_repository_shallow(r))
221 + }
222 + if (is_repository_shallow(r)) {
223 + warning(_("repository is shallow; skipping commit-graph"));
224 return 0;
225 + }
226
227 return 1;
228 }