Merge pull request #4705 from libgit2/ethomson/apply

Patch (diff) application

3 files changed, 131 insertions, 0 deletions

diff --git a/include/git2.h b/include/git2.h
index e182ce924..9239b48c8 100644
--- a/include/git2.h
+++ b/include/git2.h
@@ -9,6 +9,7 @@
 #define INCLUDE_git_git_h__
 
 #include "git2/annotated_commit.h"
+#include "git2/apply.h"
 #include "git2/attr.h"
 #include "git2/blob.h"
 #include "git2/blame.h"
diff --git a/include/git2/apply.h b/include/git2/apply.h
new file mode 100644
index 000000000..7cc1c22a8
--- /dev/null
+++ b/include/git2/apply.h
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_git_apply_h__
+#define INCLUDE_git_apply_h__
+
+#include "common.h"
+#include "types.h"
+#include "oid.h"
+#include "diff.h"
+
+/**
+ * @file git2/apply.h
+ * @brief Git patch application routines
+ * @defgroup git_apply Git patch application routines
+ * @ingroup Git
+ * @{
+ */
+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);
+
+/**
+ * When applying a patch, callback that will be made per hunk.
+ *
+ * When the callback:
+ * - returns < 0, the apply process will be aborted.
+ * - returns > 0, the hunk will not be applied, but the apply process
+ *      continues
+ * - returns 0, the hunk is applied, and the apply process continues.
+ *
+ * @param hunk The hunk to be applied
+ * @param payload User-specified payload
+ */
+typedef int (*git_apply_hunk_cb)(
+	const git_diff_hunk *hunk,
+	void *payload);
+
+/**
+ * Apply options structure
+ *
+ * Initialize with `GIT_APPLY_OPTIONS_INIT`. Alternatively, you can
+ * use `git_apply_init_options`.
+ *
+ * @see git_apply_to_tree, git_apply
+ */
+typedef struct {
+	unsigned int version;
+
+	git_apply_delta_cb delta_cb;
+	git_apply_hunk_cb hunk_cb;
+	void *payload;
+} git_apply_options;
+
+#define GIT_APPLY_OPTIONS_VERSION 1
+#define GIT_APPLY_OPTIONS_INIT {GIT_APPLY_OPTIONS_VERSION}
+
+/**
+ * Apply a `git_diff` to a `git_tree`, and return the resulting image
+ * as an index.
+ *
+ * @param out the postimage of the application
+ * @param repo the repository to apply
+ * @param preimage the tree to apply the diff to
+ * @param diff the diff to apply
+ * @param options the options for the apply (or null for defaults)
+ */
+GIT_EXTERN(int) git_apply_to_tree(
+	git_index **out,
+	git_repository *repo,
+	git_tree *preimage,
+	git_diff *diff,
+	const git_apply_options *options);
+
+typedef enum {
+	/**
+	 * Apply the patch to the workdir, leaving the index untouched.
+	 * This is the equivalent of `git apply` with no location argument.
+	 */
+	GIT_APPLY_LOCATION_WORKDIR = 0,
+
+	/**
+	 * Apply the patch to the index, leaving the working directory
+	 * untouched.  This is the equivalent of `git apply --cached`.
+	 */
+	GIT_APPLY_LOCATION_INDEX = 1,
+
+	/**
+	 * Apply the patch to both the working directory and the index.
+	 * This is the equivalent of `git apply --index`.
+	 */
+	GIT_APPLY_LOCATION_BOTH = 2,
+} git_apply_location_t;
+
+/**
+ * Apply a `git_diff` to the given repository, making changes directly
+ * in the working directory, the index, or both.
+ *
+ * @param repo the repository to apply to
+ * @param diff the diff to apply
+ * @param location the location to apply (workdir, index or both)
+ * @param options the options for the apply (or null for defaults)
+ */
+GIT_EXTERN(int) git_apply(
+	git_repository *repo,
+	git_diff *diff,
+	git_apply_location_t location,
+	const git_apply_options *options);
+
+/** @} */
+GIT_END_DECL
+#endif
diff --git a/include/git2/errors.h b/include/git2/errors.h
index c2a01de76..b0ce45fe5 100644
--- a/include/git2/errors.h
+++ b/include/git2/errors.h
@@ -57,6 +57,7 @@ typedef enum {
 	GIT_RETRY           = -32,	/**< Internal only */
 	GIT_EMISMATCH       = -33,	/**< Hashsum mismatch in object */
 	GIT_EINDEXDIRTY     = -34,	/**< Unsaved changes in the index would be overwritten */
+	GIT_EAPPLYFAIL      = -35,	/**< Patch application failed */
 } git_error_code;
 
 /**