[PATCH 02/14] packed-graph: add core.graph setting

[Derrick Stolee <stolee@gmail.com>]

The packed graph feature is controlled by the new core.graph config
setting. This defaults to 0, so the feature is opt-in.

The intention of core.graph is that a user can always stop checking
for or parsing packed graph files if core.graph=0.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 Documentation/config.txt | 3 +++
 cache.h                  | 1 +
 config.c                 | 5 +++++
 environment.c            | 1 +
 4 files changed, 10 insertions(+)

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 0e25b2c92b..e7b98fa14f 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -898,6 +898,9 @@ core.notesRef::
 This setting defaults to "refs/notes/commits", and it can be overridden by
 the `GIT_NOTES_REF` environment variable.  See linkgit:git-notes[1].
 
+core.graph::
+	Enable git commit graph feature. Allows writing and reading from .graph files.
+
 core.sparseCheckout::
 	Enable "sparse checkout" feature. See section "Sparse checkout" in
 	linkgit:git-read-tree[1] for more information.
diff --git a/cache.h b/cache.h
index d8b975a571..655a81ac90 100644
--- a/cache.h
+++ b/cache.h
@@ -825,6 +825,7 @@ extern char *git_replace_ref_base;
 extern int fsync_object_files;
 extern int core_preload_index;
 extern int core_apply_sparse_checkout;
+extern int core_graph;
 extern int precomposed_unicode;
 extern int protect_hfs;
 extern int protect_ntfs;
diff --git a/config.c b/config.c
index e617c2018d..fee90912d8 100644
--- a/config.c
+++ b/config.c
@@ -1223,6 +1223,11 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.graph")) {
+		core_graph = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp(var, "core.sparsecheckout")) {
 		core_apply_sparse_checkout = git_config_bool(var, value);
 		return 0;
diff --git a/environment.c b/environment.c
index 63ac38a46f..0c56a3d869 100644
--- a/environment.c
+++ b/environment.c
@@ -61,6 +61,7 @@ enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE;
 char *notes_ref_name;
 int grafts_replace_parents = 1;
 int core_apply_sparse_checkout;
+int core_graph;
 int merge_log_config = -1;
 int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
 unsigned long pack_size_limit_cfg;
-- 
2.16.0