Add support for cherrypick()

Author: Ross Nicoll

src/repository.c

@@ -634,6 +634,46 @@ Repository_merge(Repository *self, PyObject *py_oid)
     Py_RETURN_NONE;
 }
 
+PyDoc_STRVAR(Repository_cherrypick__doc__,
+  "cherrypick(id)\n"
+  "\n"
+  "Cherry-pick the given oid, producing changes in the index and working directory.\n"
+  "\n"
+  "Merges the given commit into HEAD as a cherrypick, writing the results into the\n"
+  "working directory. Any changes are staged for commit and any conflicts\n"
+  "are written to the index. Callers should inspect the repository's\n"
+  "index after this completes, resolve any conflicts and prepare a\n"
+  "commit.");
+
+PyObject *
+Repository_cherrypick(Repository *self, PyObject *py_oid)
+{
+    git_commit *commit;
+    git_oid oid;
+    int err;
+    size_t len;
+    git_cherrypick_options cherrypick_opts = GIT_CHERRYPICK_OPTIONS_INIT;
+
+    len = py_oid_to_git_oid(py_oid, &oid);
+    if (len == 0)
+        return NULL;
+
+    err = git_commit_lookup(&commit, self->repo, &oid);
+    if (err < 0)
+        return Error_set(err);
+
+    cherrypick_opts.checkout_opts.checkout_strategy = GIT_CHECKOUT_SAFE_CREATE;
+    err = git_cherrypick(self->repo,
+                    commit,
+                    (const git_cherrypick_options *)&cherrypick_opts);
+
+    git_commit_free(commit);
+    if (err < 0)
+        return Error_set(err);
+
+    Py_RETURN_NONE;
+}
+
 PyDoc_STRVAR(Repository_walk__doc__,
   "walk(oid[, sort_mode]) -> iterator\n"
   "\n"
@@ -1462,6 +1502,7 @@ PyMethodDef Repository_methods[] = {
     METHOD(Repository, merge_base, METH_VARARGS),
     METHOD(Repository, merge_analysis, METH_O),
     METHOD(Repository, merge, METH_O),
+    METHOD(Repository, cherrypick, METH_O),
     METHOD(Repository, read, METH_O),
     METHOD(Repository, write, METH_VARARGS),
     METHOD(Repository, create_reference_direct, METH_VARARGS),

src/repository.h

@@ -70,5 +70,6 @@ PyObject* Repository_TreeBuilder(Repository *self, PyObject *args);
 PyObject* Repository_blame(Repository *self, PyObject *args, PyObject *kwds);
 
 PyObject* Repository_merge(Repository *self, PyObject *py_oid);
+PyObject* Repository_cherrypick(Repository *self, PyObject *py_oid);
 
 #endif

test/test_cherrypick.py

@@ -0,0 +1,74 @@
+# -*- coding: UTF-8 -*-
+#
+# Copyright 2010-2014 The pygit2 contributors
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License, version 2,
+# as published by the Free Software Foundation.
+#
+# In addition to the permissions in the GNU General Public License,
+# the authors give you unlimited permission to link the compiled
+# version of this file into combinations with other programs,
+# and to distribute those combinations without any restriction
+# coming from the use of this file.  (The General Public License
+# restrictions do apply in other respects; for example, they cover
+# modification of the file, and distribution when not linked into
+# a combined executable.)
+#
+# This file is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; see the file COPYING.  If not, write to
+# the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+# Boston, MA 02110-1301, USA.
+
+"""Tests for merging and information about it."""
+
+# Import from the future
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+import unittest
+import os
+
+from pygit2 import GIT_MERGE_ANALYSIS_NONE, GIT_MERGE_ANALYSIS_NORMAL, GIT_MERGE_ANALYSIS_UP_TO_DATE
+from pygit2 import GIT_MERGE_ANALYSIS_FASTFORWARD, GIT_MERGE_ANALYSIS_UNBORN
+import pygit2
+
+from . import utils
+
+class CherrypickTestBasic(utils.RepoTestCaseForMerging):
+
+    def test_cherrypick_none(self):
+        self.assertRaises(TypeError, self.repo.cherrypick, None)
+
+    def test_cherrypick_invalid_hex(self):
+        branch_head_hex = '12345678'
+        self.assertRaises(KeyError, self.repo.cherrypick, branch_head_hex)
+
+    def test_cherrypick_already_something_in_index(self):
+        branch_head_hex = '03490f16b15a09913edb3a067a3dc67fbb8d41f1'
+        branch_oid = self.repo.get(branch_head_hex).id
+        with open(os.path.join(self.repo.workdir, 'inindex.txt'), 'w') as f:
+            f.write('new content')
+        self.repo.index.add('inindex.txt')
+        self.assertRaises(pygit2.GitError, self.repo.cherrypick, branch_oid)
+
+class CherrypickTestWithConflicts(utils.RepoTestCaseForMerging):
+
+    def test_cherrypick_remove_conflicts(self):
+        other_branch_tip = '1b2bae55ac95a4be3f8983b86cd579226d0eb247'
+        self.repo.cherrypick(other_branch_tip)
+        idx = self.repo.index
+        conflicts = idx.conflicts
+        self.assertTrue(conflicts is not None)
+        try:
+            conflicts['.gitignore']
+        except KeyError:
+            self.fail("conflicts['.gitignore'] raised KeyError unexpectedly")
+        del idx.conflicts['.gitignore']
+        self.assertRaises(KeyError, conflicts.__getitem__, '.gitignore')
+        self.assertTrue(idx.conflicts is None)