Merge pull request #630 from libgit2/ethomson/merge_file_raise_on_missing_side

Index.merge_file: raise when conflict is missing one side

Author: Vicent Martí

ext/rugged/rugged_index.c

@@ -1092,6 +1092,11 @@ static VALUE rb_git_merge_file(int argc, VALUE *argv, VALUE self)
 	else
 		rugged_exception_check(error);
 
+	if (ours == NULL)
+		rb_raise(rb_eRuntimeError, "The conflict does not have a stage 2 entry");
+	else if (theirs == NULL)
+		rb_raise(rb_eRuntimeError, "The conflict does not have a stage 3 entry");
+
 	error = git_merge_file_from_index(&merge_file_result, repo, ancestor, ours, theirs, &opts);
 	rugged_exception_check(error);
 

test/index_test.rb

@@ -289,6 +289,31 @@ def test_merge_file_with_labels
     assert_equal merge_file_result[:path], "conflicts-one.txt"
     assert_equal merge_file_result[:data], "<<<<<<< ours\nThis is most certainly a conflict!\n=======\nThis is a conflict!!!\n>>>>>>> theirs\n"
   end
+
+  def test_merge_file_without_ancestor
+    # remove the stage 1 (ancestor), this is now an add/add conflict
+    @repo.index.remove("conflicts-one.txt", 1)
+    merge_file_result = @repo.index.merge_file("conflicts-one.txt", our_label: "ours", their_label: "theirs")
+    assert !merge_file_result[:automergeable]
+    assert_equal merge_file_result[:path], "conflicts-one.txt"
+    assert_equal merge_file_result[:data], "<<<<<<< ours\nThis is most certainly a conflict!\n=======\nThis is a conflict!!!\n>>>>>>> theirs\n"
+  end
+
+  def test_merge_file_without_ours
+    # turn this into a modify/delete conflict
+    @repo.index.remove("conflicts-one.txt", 2)
+    assert_raises RuntimeError do
+      @repo.index.merge_file("conflicts-one.txt", our_label: "ours", their_label: "theirs")
+    end
+  end
+
+  def test_merge_file_without_theirs
+    # turn this into a modify/delete conflict
+    @repo.index.remove("conflicts-one.txt", 3)
+    assert_raises RuntimeError do
+      @repo.index.merge_file("conflicts-one.txt", our_label: "ours", their_label: "theirs")
+    end
+  end
 end
 
 class IndexRepositoryTest < Rugged::TestCase