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

@@ -74,16 +74,24 @@ typedef enum {
 	GIT_MERGE_FIND_RENAMES = (1 << 0),
 
 	/**
+	 * 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 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.
+	 * 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_FAIL_ON_CONFLICT = (1 << 1),
+	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

+#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);
+}
+

tests/resources/merge-recursive/.gitted/HEAD

+ref: refs/heads/branchB-1

tests/resources/merge-recursive/.gitted/config

+[core]
+	repositoryformatversion = 0
+	filemode = true
+	bare = false
+	logallrefupdates = true
+	ignorecase = true
+	precomposeunicode = true

tests/resources/merge-recursive/.gitted/info/refs

+7c7bf85e978f1d18c0566f702d2cb7766b9c8d4f	refs/heads/master

tests/resources/merge-recursive/.gitted/refs/heads/branchA-1

+539bd011c4822c560c1d17cab095006b7a10f707

tests/resources/merge-recursive/.gitted/refs/heads/branchA-2

+0bb7ed583d7e9ad507e8b902594f5c9126ea456b

tests/resources/merge-recursive/.gitted/refs/heads/branchB-1

+a34e5a16feabbd0335a633aadb8217c9f3dba58d

tests/resources/merge-recursive/.gitted/refs/heads/branchB-2

+723181f1bfd30e47a6d1d36a4d874e31e7a0a1a4

tests/resources/merge-recursive/asparagus.txt

+ASPARAGUS SOUP!
+
+Take four large bunches of asparagus, scrape it nicely, cut off one inch
+of the tops, and lay them in water, chop the stalks and put them on the
+fire with a piece of bacon, a large onion cut up, and pepper and salt;
+add two quarts of water, boil them till the stalks are quite soft, then
+pulp them through a sieve, and strain the water to it, which must be put
+back in the pot; put into it a chicken cut up, with the tops of
+asparagus which had been laid by, boil it until these last articles are
+sufficiently done, thicken with flour, butter and milk, and serve it up.

tests/resources/merge-recursive/beef.txt

+BEEF SOUP.
+
+Take the hind shin of beef, cut off all the flesh off the leg-bone,
+which must be taken away entirely, or the soup will be greasy. Wash the
+meat clean and lay it in a pot, sprinkle over it one small
+table-spoonful of pounded black pepper, and two of salt; three onions
+the size of a hen's egg, cut small, six small carrots scraped and cut
+up, two small turnips pared and cut into dice; pour on three quarts of
+water, cover the pot close, and keep it gently and steadily boiling five
+hours, which will leave about three pints of clear soup; do not let the
+pot boil over, but take off the scum carefully, as it rises. When it has
+boiled four hours, put in a small bundle of thyme and parsley, and a
+pint of celery cut small, or a tea-spoonful of celery seed pounded.
+These latter ingredients would lose their delicate flavour if boiled too
+much. Just before you take it up, brown it in the following manner: put
+a small table-spoonful of nice brown sugar into an iron skillet, set it
+on the fire and stir it till it melts and looks very dark, pour into it
+a ladle full of the soup, a little at a time; stirring it all the while.
+Strain this browning and mix it well with the soup; take out the bundle
+of thyme and parsley, put the nicest pieces of meat in your tureen, and
+pour on the soup and vegetables; put in some toasted bread cut in dice,
+and serve it up.

tests/resources/merge-recursive/bouilli.txt

+SOUP WITH BOUILLI.
+
+Take the nicest part of the thick brisket of beef, about eight pounds,
+put it into a pot with every thing directed for the other soup; make it
+exactly in the same way, only put it on an hour sooner, that you may
+have time to prepare the bouilli; after it has boiled five hours, take
+out the beef, cover up the soup and set it near the fire that it may
+keep hot. Take the skin off the beef, have the yelk of an egg well
+beaten, dip a feather in it and wash the top of your beef, sprinkle over
+it the crumb of stale bread finely grated, put it in a Dutch oven
+previously heated, put the top on with coals enough to brown, but not
+burn the beef; let it stand nearly an hour, and prepare your gravy
+thus:--Take a sufficient quantity of soup and the vegetables boiled in
+it; add to it a table-spoonful of red wine, and two of mushroom catsup,
+thicken with a little bit of butter and a little brown flour; make it
+very hot, pour it in your dish, and put the beef on it. Garnish it with
+green pickle, cut in thin slices, serve up the soup in a tureen with
+bits of toasted bread.

tests/resources/merge-recursive/gravy.txt

+GRAVY SOUP.
+
+Get eight pounds of coarse lean beef--wash it clean and lay it in your
+pot, put in the same ingredients as for the shin soup, with the same
+quantity of water, and follow the process directed for that. Strain the
+soup through a sieve, and serve it up clear, with nothing more than
+toasted bread in it; two table-spoonsful of mushroom catsup will add a
+fine flavour to the soup.

tests/resources/merge-recursive/oyster.txt

+OYSTER SOUP.
+
+Wash and drain two quarts of oysters, put them on with three quarts of
+water, three onions chopped up, two or three slices of lean ham, pepper
+and salt; boil it till reduced one-half, strain it through a sieve,
+return the liquid into the pot, put in one quart of fresh oysters, boil
+it till they are sufficiently done, and thicken the soup with four
+spoonsful of flour, two gills of rich cream, and the yelks of six new
+laid eggs beaten well; boil it a few minutes after the thickening is put
+in. Take care that it does not curdle, and that the flour is not in
+lumps; serve it up with the last oysters that were put in. If the
+flavour of thyme be agreeable, you may put in a little, but take care
+that it does not boil in it long enough to discolour the soup.

tests/resources/merge-recursive/veal.txt

+VEAL SOUP!
+
+Put into a pot three quarts of water, three onions cut small, one
+spoonful of black pepper pounded, and two of salt, with two or three
+slices of lean ham; let it boil steadily two hours; skim it
+occasionally, then put into it a shin of veal, let it boil two hours
+longer. take out the slices of ham, and skim off the grease if any
+should rise, take a gill of good cream, mix with it two table-spoonsful
+of flour very nicely, and the yelks of two eggs beaten well, strain this
+mixture, and add some chopped parsley; pour some soup on by degrees,
+stir it well, and pour it into the pot, continuing to stir until it has
+boiled two or three minutes to take off the raw taste of the eggs. If
+the cream be not perfectly sweet, and the eggs quite new, the thickening
+will curdle in the soup. For a change you may put a dozen ripe tomatos
+in, first taking off their skins, by letting them stand a few minutes in
+hot water, when they may be easily peeled. When made in this way you
+must thicken it with the flour only. Any part of the veal may be used,
+but the shin or knuckle is the nicest.