Support for diff merge operation added

src/pygit2/diff.c

@@ -53,8 +53,8 @@ static int diff_hunk_cb(
 
     hunks = PyDict_GetItemString(cb_data, "hunks");
     if(hunks == NULL) {
-    hunks = PyList_New(0);
-    PyDict_SetItemString(cb_data, "hunks", hunks);
+        hunks = PyList_New(0);
+        PyDict_SetItemString(cb_data, "hunks", hunks);
     }
 
     hunk = (Hunk*) PyType_GenericNew(&HunkType, NULL, NULL);
@@ -237,6 +237,24 @@ PyTypeObject HunkType = {
     0,                                         /* tp_new            */
 };
 
+PyObject *
+Diff_merge(Diff *self, PyObject *args)
+{
+    Diff *py_diff;
+    int err;
+
+    if (!PyArg_ParseTuple(args, "O!", &DiffType, &py_diff))
+        return NULL;
+    if (py_diff->repo->repo != self->repo->repo)
+        return Error_set(GIT_ERROR);
+
+    err = git_diff_merge(self->diff, py_diff->diff);
+    if (err < 0)
+        return Error_set(err);
+
+    Py_RETURN_NONE;
+}
+
 static void
 Diff_dealloc(Diff *self)
 {
@@ -251,6 +269,12 @@ PyGetSetDef Diff_getseters[] = {
     {NULL}
 };
 
+static PyMethodDef Diff_methods[] = {
+    {"merge", (PyCFunction)Diff_merge, METH_VARARGS,
+     "Merge one diff into another."},
+    {NULL, NULL, 0, NULL}
+};
+
 PyTypeObject DiffType = {
     PyVarObject_HEAD_INIT(NULL, 0)
     "pygit2.Diff",                             /* tp_name           */
@@ -279,7 +303,7 @@ PyTypeObject DiffType = {
     0,                                         /* tp_weaklistoffset */
     0,                                         /* tp_iter           */
     0,                                         /* tp_iternext       */
-    0,                                         /* tp_methods        */
+    Diff_methods,                              /* tp_methods        */
     0,                                         /* tp_members        */
     Diff_getseters,                            /* tp_getset         */
     0,                                         /* tp_base           */

test/data/testrepo.git/objects/2c/dae28389c059815e951d0bb9eed6533f61a46b

@@ -0,0 +1,2 @@
+x
<01>OIj1<10>Y<EFBFBD><59><EFBFBD>A<EFBFBD>֑ <20>}<7D>!д<><1E>̂<EFBFBD>
+~~<7E>I^<5E>[<15>PE<50><7
<01><>E:3<>RMu>D

test/data/testrepo.git/objects/39/a3001fcc2b9541fdcf4be2d662618a5d213f47

@@ -0,0 +1 @@
+x
<01>O9N1$<24>+:G<>z|<7C>=B<><42>|<7C>G{m-s<><73><EFBFBD><EFBFBD><EFBFBD><EFBFBD>/ <20>R<1D>J<EFBFBD><4A>6<06><>w"p*<2A>蝵Q<E89DB5>4'CK^<5E><>b<EFBFBD><62>&/NU<>G<><47>1<EFBFBD>B=<3D><><EFBFBD>4)<29><><EFBFBD>1)늝g<EB8A9D>1<>1qBn\<5C><1F><1D><>AWx9d}<7D><><EFBFBD><1E>[<5B><>!<21><><EFBFBD>&<26><>F<EFBFBD><46><EFBFBD>g<EFBFBD>E<><19><>ϸ<EFBFBD><CFB8><EFBFBD>g`9p<39><70>>)<1E><>c<EFBFBD>j<EFBFBD>.4<EFBFBD>+
<01><><EFBFBD><EFBFBD>]<5D>̝O<CC9D><4F><EFBFBD>W)<29>
<01>M]=

test/data/testrepo.git/refs/heads/master

@@ -1 +1 @@
-5fe808e8953c12735680c257f56600cb0de44b10
+2cdae28389c059815e951d0bb9eed6533f61a46b

test/test_diff.py

@@ -39,6 +39,7 @@ __author__ = 'Nico.Geyso@FU-Berlin.de (Nico von Geyso)'
 
 COMMIT_SHA1_1 = '5fe808e8953c12735680c257f56600cb0de44b10'
 COMMIT_SHA1_2 = 'c2792cfa289ae6321ecf2cd5806c2194b0fd070c'
+COMMIT_SHA1_3 = '2cdae28389c059815e951d0bb9eed6533f61a46b'
 PATCH = b"""diff --git a/a b/a
 index 7f129fd..af431f2 100644
 --- a/a
@@ -85,6 +86,36 @@ class DiffTest(utils.BareRepoTestCase):
         self.assertEqual(hunk.old_data, b'a contents 2\n')
         self.assertEqual(hunk.new_data, b'a contents\n')
 
+    def test_diff_merge(self):
+        commit_a = self.repo[COMMIT_SHA1_1]
+        commit_b = self.repo[COMMIT_SHA1_2]
+        commit_c = self.repo[COMMIT_SHA1_3]
+
+        diff_b = commit_a.tree.diff(commit_b.tree)
+        self.assertIsNotNone(diff_b)
+
+        diff_c = commit_b.tree.diff(commit_c.tree)
+        self.assertIsNotNone(diff_c)
+
+        self.assertNotIn(('b','b', 3), diff_b.changes['files'])
+        self.assertIn(('b','b', 3), diff_c.changes['files'])
+
+        diff_b.merge(diff_c)
+
+        self.assertIn(('b','b', 3), diff_b.changes['files'])
+
+        hunk = diff_b.changes['hunks'][1]
+        self.assertEqual(hunk.old_start, 1)
+        self.assertEqual(hunk.old_lines, 0)
+        self.assertEqual(hunk.new_start, 1)
+        self.assertEqual(hunk.new_lines, 0)
+
+        self.assertEqual(hunk.old_file, 'b')
+        self.assertEqual(hunk.new_file, 'b')
+
+        self.assertEqual(hunk.old_data, b'b contents\n')
+        self.assertEqual(hunk.new_data, b'b contents 2\n')
+
     def test_diff_patch(self):
         commit_a = self.repo[COMMIT_SHA1_1]
         commit_b = self.repo[COMMIT_SHA1_2]