commit-graph: not compatible with replace objects

Create new method commit_graph_compatible(r) to check if a given
repository r is compatible with the commit-graph feature. Fill the
method with a check to see if replace-objects exist. Test this
interaction succeeds, including ignoring an existing commit-graph and
failing to write a new commit-graph. However, we do ensure that
we write a new commit-graph by setting read_replace_refs to 0, thereby
ignoring the replace refs.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 0bf0c486575a8557b729658ce05be02d28a1a8b8..da737df321528088d8aa20e3e87e803336b1f550 100644 (file)
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -120,6 +120,8 @@ static int graph_read(int argc, const char **argv)
        return 0;
 }
 
+extern int read_replace_refs;
+
 static int graph_write(int argc, const char **argv)
 {
        struct string_list *pack_indexes = NULL;
@@ -150,6 +152,8 @@ static int graph_write(int argc, const char **argv)
        if (!opts.obj_dir)
                opts.obj_dir = get_object_directory();
 
+       read_replace_refs = 0;
+
        if (opts.reachable) {
                write_commit_graph_reachable(opts.obj_dir, opts.append);
                return 0;

diff --git a/commit-graph.c b/commit-graph.c
index b0a55ad128fbcaa2e34c25b8487856d20d0ad3d5..2c01fa433f3d32c653b9c06f248fac58fece5262 100644 (file)
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -13,6 +13,8 @@
 #include "commit-graph.h"
 #include "object-store.h"
 #include "alloc.h"
+#include "hashmap.h"
+#include "replace-object.h"
 
 #define GRAPH_SIGNATURE 0x43475048 /* "CGPH" */
 #define GRAPH_CHUNKID_OIDFANOUT 0x4f494446 /* "OIDF" */
@@ -56,6 +58,19 @@ static struct commit_graph *alloc_commit_graph(void)
        return g;
 }
 
+extern int read_replace_refs;
+
+static int commit_graph_compatible(struct repository *r)
+{
+       if (read_replace_refs) {
+               prepare_replace_object(r);
+               if (hashmap_get_size(&r->objects->replace_map->map))
+                       return 0;
+       }
+
+       return 1;
+}
+
 struct commit_graph *load_commit_graph_one(const char *graph_file)
 {
        void *graph_map;
@@ -223,6 +238,9 @@ static int prepare_commit_graph(struct repository *r)
                 */
                return 0;
 
+       if (!commit_graph_compatible(r))
+               return 0;
+
        obj_dir = r->objects->objectdir;
        prepare_commit_graph_one(r, obj_dir);
        prepare_alt_odb(r);
@@ -693,6 +711,9 @@ void write_commit_graph(const char *obj_dir,
        int num_extra_edges;
        struct commit_list *parent;
 
+       if (!commit_graph_compatible(the_repository))
+               return;
+
        oids.nr = 0;
        oids.alloc = approximate_object_count() / 4;
 

diff --git a/replace-object.c b/replace-object.c
index 3c17864eb7d842f7abdbd6a6d87106468376f659..9821f1477edab21d98bfeb89edd301f6d6257753 100644 (file)
--- a/replace-object.c
+++ b/replace-object.c
@@ -32,7 +32,7 @@ static int register_replace_ref(struct repository *r,
        return 0;
 }
 
-static void prepare_replace_object(struct repository *r)
+void prepare_replace_object(struct repository *r)
 {
        if (r->objects->replace_map)
                return;

diff --git a/replace-object.h b/replace-object.h
index 9345e105ddcaa38cf9e856df70d960245a3b696c..16528df942f79e3d7ce65d99e0103395d0c69f51 100644 (file)
--- a/replace-object.h
+++ b/replace-object.h
@@ -10,6 +10,8 @@ struct replace_object {
        struct object_id replacement;
 };
 
+void prepare_replace_object(struct repository *r);
+
 /*
  * This internal function is only declared here for the benefit of
  * lookup_replace_object().  Please do not call it directly.

diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 4f17d7701e456bbb0992efdba2861e1dac8f7c23..e0c3c60f66a163bdfa0b73713836c3e16721dc7f 100755 (executable)
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -259,6 +259,28 @@ test_expect_success 'check that gc computes commit-graph' '
        test_cmp commit-graph-after-gc $objdir/info/commit-graph
 '
 
+test_expect_success 'replace-objects invalidates commit-graph' '
+       cd "$TRASH_DIRECTORY" &&
+       test_when_finished rm -rf replace &&
+       git clone full replace &&
+       (
+               cd replace &&
+               git commit-graph write --reachable &&
+               test_path_is_file .git/objects/info/commit-graph &&
+               git replace HEAD~1 HEAD~2 &&
+               git -c core.commitGraph=false log >expect &&
+               git -c core.commitGraph=true log >actual &&
+               test_cmp expect actual &&
+               git commit-graph write --reachable &&
+               git -c core.commitGraph=false --no-replace-objects log >expect &&
+               git -c core.commitGraph=true --no-replace-objects log >actual &&
+               test_cmp expect actual &&
+               rm -rf .git/objects/info/commit-graph &&
+               git commit-graph write --reachable &&
+               test_path_is_file .git/objects/info/commit-graph
+       )
+'
+
 # the verify tests below expect the commit-graph to contain
 # exactly the commits reachable from the commits/8 branch.
 # If the file changes the set of commits in the list, then the