Add Repository.message

pygit2/decl/repository.h

@@ -87,6 +87,7 @@ int git_repository_ident(const char **name, const char **email, const git_reposi
 int git_repository_set_ident(git_repository *repo, const char *name, const char *email);
 int git_repository_index(git_index **out, git_repository *repo);
 git_repository_state_t git_repository_state(git_repository *repo);
-
+int git_repository_message(git_buf *out, git_repository *repo);
+int git_repository_message_remove(git_repository *repo);
 int git_repository_submodule_cache_all(git_repository *repo);
 int git_repository_submodule_cache_clear(git_repository *repo);

pygit2/repository.py

@@ -957,6 +957,51 @@ def merge(self, id, favor="normal", flags=None, file_flags=None):
         C.git_annotated_commit_free(commit_ptr[0])
         check_error(err)
 
+    #
+    # Prepared message (MERGE_MSG)
+    #
+    @property
+    def raw_message(self) -> bytes:
+        """
+        Retrieve git's prepared message (bytes).
+        See `Repository.message` for more information.
+        """
+        buf = ffi.new('git_buf *', (ffi.NULL, 0))
+        try:
+            err = C.git_repository_message(buf, self._repo)
+            if err == C.GIT_ENOTFOUND:
+                return b''
+            check_error(err)
+            return ffi.string(buf.ptr)
+        finally:
+            C.git_buf_dispose(buf)
+
+    @property
+    def message(self) -> str:
+        """
+        Retrieve git's prepared message.
+
+        Operations such as git revert/cherry-pick/merge with the -n option stop
+        just short of creating a commit with the changes and save their
+        prepared message in .git/MERGE_MSG so the next git-commit execution can
+        present it to the user for them to amend if they wish.
+
+        Use this function to get the contents of this file. Don't forget to
+        call `Repository.remove_message()` after you create the commit.
+
+        Note that the message is also removed by `Repository.state_cleanup()`.
+
+        If there is no such message, an empty string is returned.
+        """
+        return self.raw_message.decode('utf-8')
+
+    def remove_message(self):
+        """
+        Remove git's prepared message.
+        """
+        err = C.git_repository_message_remove(self._repo)
+        check_error(err)
+
     #
     # Describe
     #

test/test_cherrypick.py

@@ -50,15 +50,22 @@ def test_cherrypick_already_something_in_index(mergerepo):
 
 def test_cherrypick_remove_conflicts(mergerepo):
     assert mergerepo.state() == RepositoryState.NONE
+    assert not mergerepo.message
+
     other_branch_tip = '1b2bae55ac95a4be3f8983b86cd579226d0eb247'
     mergerepo.cherrypick(other_branch_tip)
+
     assert mergerepo.state() == RepositoryState.CHERRYPICK
+    assert mergerepo.message.startswith("commit to provoke a conflict")
+
     idx = mergerepo.index
     conflicts = idx.conflicts
     assert conflicts is not None
     conflicts['.gitignore']
     del idx.conflicts['.gitignore']
     with pytest.raises(KeyError): conflicts.__getitem__('.gitignore')
     assert idx.conflicts is None
+
     mergerepo.state_cleanup()
     assert mergerepo.state() == RepositoryState.NONE
+    assert not mergerepo.message

test/test_merge.py

@@ -286,3 +286,26 @@ def test_merge_mergeheads(mergerepo):
 
     mergerepo.state_cleanup()
     assert mergerepo.listall_mergeheads() == [], "state_cleanup() should wipe the mergeheads"
+
+
+def test_merge_message(mergerepo):
+    assert not mergerepo.message
+    assert not mergerepo.raw_message
+
+    branch_head_hex = '1b2bae55ac95a4be3f8983b86cd579226d0eb247'
+    mergerepo.merge(branch_head_hex)
+
+    assert mergerepo.message.startswith(f"Merge commit '{branch_head_hex}'")
+    assert mergerepo.message.encode('utf-8') == mergerepo.raw_message
+
+    mergerepo.state_cleanup()
+    assert not mergerepo.message
+
+
+def test_merge_remove_message(mergerepo):
+    branch_head_hex = '1b2bae55ac95a4be3f8983b86cd579226d0eb247'
+    mergerepo.merge(branch_head_hex)
+
+    assert mergerepo.message.startswith(f"Merge commit '{branch_head_hex}'")
+    mergerepo.remove_message()
+    assert not mergerepo.message