merge: add simple recursive test

Add a simple recursive test - where multiple ancestors exist and
creating a virtual merge base from them would prevent a conflict.

include/git2/merge.h

@@ -73,17 +73,25 @@ typedef enum {
 	 */
 	GIT_MERGE_FIND_RENAMES = (1 << 0),
 
-	/**
-	 * Do not write the REUC extension on the generated index
-	 */
-	GIT_MERGE_SKIP_REUC = (1 << 2),
-
 	/**
 	 * If a conflict occurs, exit immediately instead of attempting to
 	 * continue resolving conflicts.  The merge operation will fail with
 	 * GIT_EMERGECONFLICT and no index will be returned.
 	 */
 	GIT_MERGE_FAIL_ON_CONFLICT = (1 << 1),
+
+	/**
+	 * Do not write the REUC extension on the generated index
+	 */
+	GIT_MERGE_SKIP_REUC = (1 << 2),
+
+	/**
+	 * If the commits being merged have multiple merge bases, do not build
+	 * a recursive merge base (by merging the multiple merge bases),
+	 * instead simply use the first base.  This flag provides a similar
+	 * merge base to `git-merge-resolve`.
+	 */
+	GIT_MERGE_NO_RECURSIVE = (1 << 3),
 } git_merge_flag_t;
 
 /**

tests/merge/merge_helpers.c

@@ -4,6 +4,7 @@
 #include "tree.h"
 #include "merge_helpers.h"
 #include "merge.h"
+#include "index.h"
 #include "git2/merge.h"
 #include "git2/sys/index.h"
 #include "git2/annotated_commit.h"
@@ -239,7 +240,7 @@ int merge_test_index(git_index *index, const struct merge_index_entry expected[]
 	const git_index_entry *index_entry;
 
 	/*
-	dump_index_entries(&index->entries);
+	merge__dump_index_entries(&index->entries);
 	*/
 
 	if (git_index_entrycount(index) != expected_len)

tests/merge/trees/recursive.c

@@ -0,0 +1,110 @@
+#include "clar_libgit2.h"
+#include "git2/repository.h"
+#include "git2/merge.h"
+#include "merge.h"
+#include "../merge_helpers.h"
+
+static git_repository *repo;
+
+#define TEST_REPO_PATH "merge-recursive"
+
+void test_merge_trees_recursive__initialize(void)
+{
+	repo = cl_git_sandbox_init(TEST_REPO_PATH);
+}
+
+void test_merge_trees_recursive__cleanup(void)
+{
+	cl_git_sandbox_cleanup();
+}
+
+void test_merge_trees_recursive__one(void)
+{
+	git_index *index;
+	git_merge_options opts = GIT_MERGE_OPTIONS_INIT;
+
+	struct merge_index_entry merge_index_entries[] = {
+		{ 0100644, "dea7215f259b2cced87d1bda6c72f8b4ce37a2ff", 0, "asparagus.txt" },
+		{ 0100644, "68f6182f4c85d39e1309d97c7e456156dc9c0096", 0, "beef.txt" },
+		{ 0100644, "4b7c5650008b2e747fe1809eeb5a1dde0e80850a", 0, "bouilli.txt" },
+		{ 0100644, "c4e6cca3ec6ae0148ed231f97257df8c311e015f", 0, "gravy.txt" },
+		{ 0100644, "68af1fc7407fd9addf1701a87eb1c95c7494c598", 0, "oyster.txt" },
+		{ 0100644, "94d2c01087f48213bd157222d54edfefd77c9bba", 0, "veal.txt" },
+	};
+
+	cl_git_pass(merge_commits_from_branches(&index, repo, "branchA-1", "branchA-2", &opts));
+
+	cl_assert(merge_test_index(index, merge_index_entries, 6));
+
+	git_index_free(index);
+}
+
+void test_merge_trees_recursive__one_norecursive(void)
+{
+	git_index *index;
+	git_merge_options opts = GIT_MERGE_OPTIONS_INIT;
+
+	struct merge_index_entry merge_index_entries[] = {
+		{ 0100644, "dea7215f259b2cced87d1bda6c72f8b4ce37a2ff", 0, "asparagus.txt" },
+		{ 0100644, "68f6182f4c85d39e1309d97c7e456156dc9c0096", 0, "beef.txt" },
+		{ 0100644, "4b7c5650008b2e747fe1809eeb5a1dde0e80850a", 0, "bouilli.txt" },
+		{ 0100644, "c4e6cca3ec6ae0148ed231f97257df8c311e015f", 0, "gravy.txt" },
+		{ 0100644, "68af1fc7407fd9addf1701a87eb1c95c7494c598", 0, "oyster.txt" },
+		{ 0100644, "94d2c01087f48213bd157222d54edfefd77c9bba", 0, "veal.txt" },
+	};
+
+	opts.flags |= GIT_MERGE_NO_RECURSIVE;
+
+	cl_git_pass(merge_commits_from_branches(&index, repo, "branchA-1", "branchA-2", &opts));
+
+	cl_assert(merge_test_index(index, merge_index_entries, 6));
+
+	git_index_free(index);
+}
+
+void test_merge_trees_recursive__two(void)
+{
+	git_index *index;
+	git_merge_options opts = GIT_MERGE_OPTIONS_INIT;
+
+	struct merge_index_entry merge_index_entries[] = {
+		{ 0100644, "ffb36e513f5fdf8a6ba850a20142676a2ac4807d", 0, "asparagus.txt" },
+		{ 0100644, "68f6182f4c85d39e1309d97c7e456156dc9c0096", 0, "beef.txt" },
+		{ 0100644, "4b7c5650008b2e747fe1809eeb5a1dde0e80850a", 0, "bouilli.txt" },
+		{ 0100644, "c4e6cca3ec6ae0148ed231f97257df8c311e015f", 0, "gravy.txt" },
+		{ 0100644, "68af1fc7407fd9addf1701a87eb1c95c7494c598", 0, "oyster.txt" },
+		{ 0100644, "666ffdfcf1eaa5641fa31064bf2607327e843c09", 0, "veal.txt" },
+	};
+
+	cl_git_pass(merge_commits_from_branches(&index, repo, "branchB-1", "branchB-2", &opts));
+
+	cl_assert(merge_test_index(index, merge_index_entries, 6));
+
+	git_index_free(index);
+}
+
+void test_merge_trees_recursive__two_norecursive(void)
+{
+	git_index *index;
+	git_merge_options opts = GIT_MERGE_OPTIONS_INIT;
+
+	opts.flags |= GIT_MERGE_NO_RECURSIVE;
+
+	struct merge_index_entry merge_index_entries[] = {
+		{ 0100644, "ffb36e513f5fdf8a6ba850a20142676a2ac4807d", 0, "asparagus.txt" },
+		{ 0100644, "68f6182f4c85d39e1309d97c7e456156dc9c0096", 0, "beef.txt" },
+		{ 0100644, "4b7c5650008b2e747fe1809eeb5a1dde0e80850a", 0, "bouilli.txt" },
+		{ 0100644, "c4e6cca3ec6ae0148ed231f97257df8c311e015f", 0, "gravy.txt" },
+		{ 0100644, "68af1fc7407fd9addf1701a87eb1c95c7494c598", 0, "oyster.txt" },
+		{ 0100644, "cb49ad76147f5f9439cbd6133708b76142660660", 1, "veal.txt" },
+		{ 0100644, "b2a81ead9e722af0099fccfb478cea88eea749a2", 2, "veal.txt" },
+		{ 0100644, "4e21d2d63357bde5027d1625f5ec6b430cdeb143", 3, "veal.txt" },
+	};
+
+	cl_git_pass(merge_commits_from_branches(&index, repo, "branchB-1", "branchB-2", &opts));
+
+	cl_assert(merge_test_index(index, merge_index_entries, 8));
+
+	git_index_free(index);
+}
+