apply: introduce a delta callback

Introduce a callback to the application options that allow callers to
add a per-delta callback.  The callback can return an error code to stop
patch application, or can return a value to skip the application of a
particular delta.

1 files changed, 19 insertions, 0 deletions

diff --git a/include/git2/apply.h b/include/git2/apply.h
index cdeb9ed4c..eb9cad4d1 100644
--- a/include/git2/apply.h
+++ b/include/git2/apply.h
@@ -22,6 +22,22 @@
 GIT_BEGIN_DECL
 
 /**
+ * When applying a patch, callback that will be made per delta (file).
+ *
+ * When the callback:
+ * - returns < 0, the apply process will be aborted.
+ * - returns > 0, the delta will not be applied, but the apply process
+ *      continues
+ * - returns 0, the delta is applied, and the apply process continues.
+ *
+ * @param delta The delta to be applied
+ * @param payload User-specified payload
+ */
+typedef int (*git_apply_delta_cb)(
+	const git_diff_delta *delta,
+	void *payload);
+
+/**
  * Apply options structure
  *
  * Initialize with `GIT_APPLY_OPTIONS_INIT`. Alternatively, you can
@@ -31,6 +47,9 @@ GIT_BEGIN_DECL
  */
 typedef struct {
 	unsigned int version;
+
+	git_apply_delta_cb delta_cb;
+	void *payload;
 } git_apply_options;
 
 #define GIT_APPLY_OPTIONS_VERSION 1