Merge pull request #6557 from libgit2/ethomson/shallow

Shallow (#6396) with some fixes from review

3 files changed, 39 insertions, 3 deletions

diff --git a/include/git2/errors.h b/include/git2/errors.h
index a61964bbb..e634a97c1 100644
--- a/include/git2/errors.h
+++ b/include/git2/errors.h
@@ -109,7 +109,8 @@ typedef enum {
 	GIT_ERROR_WORKTREE,
 	GIT_ERROR_SHA,
 	GIT_ERROR_HTTP,
-	GIT_ERROR_INTERNAL
+	GIT_ERROR_INTERNAL,
+	GIT_ERROR_GRAFTS
 } git_error_t;
 
 /**
diff --git a/include/git2/remote.h b/include/git2/remote.h
index 8c9c26f3f..e9065b250 100644
--- a/include/git2/remote.h
+++ b/include/git2/remote.h
@@ -702,6 +702,15 @@ typedef enum {
 	GIT_REMOTE_DOWNLOAD_TAGS_ALL
 } git_remote_autotag_option_t;
 
+/** Constants for fetch depth (shallowness of fetch). */
+typedef enum {
+	/** The fetch is "full" (not shallow). This is the default. */
+	GIT_FETCH_DEPTH_FULL = 0,
+
+	/** The fetch should "unshallow" and fetch missing data. */
+	GIT_FETCH_DEPTH_UNSHALLOW = 2147483647
+} git_fetch_depth_t;
+
 /**
  * Fetch options structure.
  *
@@ -744,6 +753,15 @@ typedef struct {
 	git_proxy_options proxy_opts;
 
 	/**
+	 * Depth of the fetch to perform, or `GIT_FETCH_DEPTH_FULL`
+	 * (or `0`) for full history, or `GIT_FETCH_DEPTH_UNSHALLOW`
+	 * to "unshallow" a shallow repository.
+	 *
+	 * The default is full (`GIT_FETCH_DEPTH_FULL` or `0`).
+	 */
+	int depth;
+
+	/**
 	 * Whether to allow off-site redirects.  If this is not
 	 * specified, the `http.followRedirects` configuration setting
 	 * will be consulted.
diff --git a/include/git2/sys/transport.h b/include/git2/sys/transport.h
index b70582188..96a35d08c 100644
--- a/include/git2/sys/transport.h
+++ b/include/git2/sys/transport.h
@@ -25,6 +25,14 @@
 
 GIT_BEGIN_DECL
 
+typedef struct {
+	const git_remote_head * const *refs;
+	size_t refs_len;
+	git_oid *shallow_roots;
+	size_t shallow_roots_len;
+	int depth;
+} git_fetch_negotiation;
+
 struct git_transport {
 	unsigned int version; /**< The struct version */
 
@@ -96,8 +104,17 @@ struct git_transport {
 	int GIT_CALLBACK(negotiate_fetch)(
 		git_transport *transport,
 		git_repository *repo,
-		const git_remote_head * const *refs,
-		size_t count);
+		const git_fetch_negotiation *fetch_data);
+
+	/**
+	 * Return the shallow roots of the remote.
+	 *
+	 * This function may be called after a successful call to
+	 * `negotiate_fetch`.
+	 */
+	int GIT_CALLBACK(shallow_roots)(
+		git_oidarray *out,
+		git_transport *transport);
 
 	/**
 	 * Start downloading the packfile from the remote repository.