commit-graph: turn on commit-graph by default

The commit-graph feature has seen a lot of activity in the past
year or so since it was introduced. The feature is a critical
performance enhancement for medium- to large-sized repos, and
does not significantly hurt small repos.

Change the defaults for core.commitGraph and gc.writeCommitGraph
to true so users benefit from this feature by default.

There are several places in the test suite where the environment
variable GIT_TEST_COMMIT_GRAPH is disabled to avoid reading a
commit-graph, if it exists. The config option overrides the
environment, so swap these. Some GIT_TEST_COMMIT_GRAPH assignments
remain, and those are to avoid writing a commit-graph when a new
commit is created.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/repo-settings.c b/repo-settings.c
index 309577f6bc..d00b675687 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -2,6 +2,8 @@
 #include "config.h"
 #include "repository.h"
 
+#define UPDATE_DEFAULT_BOOL(s,v) do { if (s == -1) { s = v; } } while(0)
+
 void prepare_repo_settings(struct repository *r)
 {
 	int value;
@@ -16,6 +18,8 @@ void prepare_repo_settings(struct repository *r)
 		r->settings.core_commit_graph = value;
 	if (!repo_config_get_bool(r, "gc.writecommitgraph", &value))
 		r->settings.gc_write_commit_graph = value;
+	UPDATE_DEFAULT_BOOL(r->settings.core_commit_graph, 1);
+	UPDATE_DEFAULT_BOOL(r->settings.gc_write_commit_graph, 1);
 
 	if (!repo_config_get_bool(r, "index.version", &value))
 		r->settings.index_version = value;