repo-settings: create feature.experimental setting

The 'feature.experimental' setting includes config options that are
not committed to become defaults, but could use additional testing.

Update the following config settings to take new defaults, and to
use the repo_settings struct if not already using them:

* 'pack.useSparse=true'

* 'fetch.negotiationAlgorithm=skipping'

In the case of fetch.negotiationAlgorithm, the existing logic
would load the config option only when about to use the setting,
so had a die() statement on an unknown string value. This is
removed as now the config is parsed under prepare_repo_settings().
In general, this die() is probably misplaced and not valuable.
A test was removed that checked this die() statement executed.

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

1 files changed, 13 insertions, 0 deletions

diff --git a/repo-settings.c b/repo-settings.c
index d5bf9069f4..3779b85c17 100644
--- a/repo-settings.c
+++ b/repo-settings.c
@@ -36,16 +36,29 @@ void prepare_repo_settings(struct repository *r)
 		free(strval);
 	}
 
+	if (!repo_config_get_string(r, "fetch.negotiationalgorithm", &strval)) {
+		if (!strcasecmp(strval, "skipping"))
+			r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_SKIPPING;
+		else
+			r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_DEFAULT;
+	}
+
 	if (!repo_config_get_bool(r, "pack.usesparse", &value))
 		r->settings.pack_use_sparse = value;
 	if (!repo_config_get_bool(r, "feature.manyfiles", &value) && value) {
 		UPDATE_DEFAULT_BOOL(r->settings.index_version, 4);
 		UPDATE_DEFAULT_BOOL(r->settings.core_untracked_cache, UNTRACKED_CACHE_WRITE);
 	}
+	if (!repo_config_get_bool(r, "feature.experimental", &value) && value) {
+		UPDATE_DEFAULT_BOOL(r->settings.pack_use_sparse, 1);
+		UPDATE_DEFAULT_BOOL(r->settings.fetch_negotiation_algorithm, FETCH_NEGOTIATION_SKIPPING);
+	}
 
 	/* Hack for test programs like test-dump-untracked-cache */
 	if (ignore_untracked_cache_config)
 		r->settings.core_untracked_cache = UNTRACKED_CACHE_KEEP;
 	else
 		UPDATE_DEFAULT_BOOL(r->settings.core_untracked_cache, UNTRACKED_CACHE_KEEP);
+
+	UPDATE_DEFAULT_BOOL(r->settings.fetch_negotiation_algorithm, FETCH_NEGOTIATION_DEFAULT);
 }