commit-graph: check mixed generation validation when loading chain file

In read_commit_graph_one(), we call validate_mixed_generation_chain()
after loading the graph. Even though we don't check the return value,
this has the side effect of clearing the read_generation_data flag,
which is important when working with mixed generation numbers.

But doing this in load_commit_graph_chain_fd_st() makes more sense:

  1. We are calling it even when we did not load a chain at all, which
     is pointless (you cannot have mixed generations in a single file).

  2. For now, all callers load the graph via read_commit_graph_one().
     But the point of factoring out the open/load in the previous commit
     was to let "commit-graph verify" call them separately. So it needs
     to trigger this function as part of the load.

     Without this patch, the mixed-generation tests in t5324 would start
     failing on "git commit-graph verify" calls, once we switch to using
     a separate open/load call there.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/commit-graph.c b/commit-graph.c
index 12cdd9af8e86b0067e1288062d94683a066db72a..8b29c6de24659f19121893b3b3d0a20a27b4e5e1 100644 (file)
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -473,6 +473,31 @@ static struct commit_graph *load_commit_graph_v1(struct repository *r,
        return g;
 }
 
+/*
+ * returns 1 if and only if all graphs in the chain have
+ * corrected commit dates stored in the generation_data chunk.
+ */
+static int validate_mixed_generation_chain(struct commit_graph *g)
+{
+       int read_generation_data = 1;
+       struct commit_graph *p = g;
+
+       while (read_generation_data && p) {
+               read_generation_data = p->read_generation_data;
+               p = p->base_graph;
+       }
+
+       if (read_generation_data)
+               return 1;
+
+       while (g) {
+               g->read_generation_data = 0;
+               g = g->base_graph;
+       }
+
+       return 0;
+}
+
 static int add_graph_to_chain(struct commit_graph *g,
                              struct commit_graph *chain,
                              struct object_id *oids,
@@ -581,6 +606,8 @@ struct commit_graph *load_commit_graph_chain_fd_st(struct repository *r,
                }
        }
 
+       validate_mixed_generation_chain(graph_chain);
+
        free(oids);
        fclose(fp);
        strbuf_release(&line);
@@ -605,31 +632,6 @@ static struct commit_graph *load_commit_graph_chain(struct repository *r,
        return g;
 }
 
-/*
- * returns 1 if and only if all graphs in the chain have
- * corrected commit dates stored in the generation_data chunk.
- */
-static int validate_mixed_generation_chain(struct commit_graph *g)
-{
-       int read_generation_data = 1;
-       struct commit_graph *p = g;
-
-       while (read_generation_data && p) {
-               read_generation_data = p->read_generation_data;
-               p = p->base_graph;
-       }
-
-       if (read_generation_data)
-               return 1;
-
-       while (g) {
-               g->read_generation_data = 0;
-               g = g->base_graph;
-       }
-
-       return 0;
-}
-
 struct commit_graph *read_commit_graph_one(struct repository *r,
                                           struct object_directory *odb)
 {
@@ -638,8 +640,6 @@ struct commit_graph *read_commit_graph_one(struct repository *r,
        if (!g)
                g = load_commit_graph_chain(r, odb);
 
-       validate_mixed_generation_chain(g);
-
        return g;
 }