merge-recursive: remove useless parameter in merge_trees()

merge_trees() took a results parameter that would only be written when
opt->call_depth was positive, which is never the case now that
merge_trees_internal() has been split from merge_trees().  Remove the
misleading and unused parameter from merge_trees().

While at it, add some comments explaining how the output of
merge_trees() and merge_recursive() differ.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index d5b946dc3af73e2a35af69a4669206164ffc5ef8..90e0eaf25ee84ed3059e2ea72d18b954bd532a2d 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -708,7 +708,6 @@ static int merge_working_tree(const struct checkout_opts *opts,
                         * give up or do a real merge, depending on
                         * whether the merge flag was used.
                         */
-                       struct tree *result;
                        struct tree *work;
                        struct tree *old_tree;
                        struct merge_options o;
@@ -780,8 +779,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
                        ret = merge_trees(&o,
                                          new_tree,
                                          work,
-                                         old_tree,
-                                         &result);
+                                         old_tree);
                        if (ret < 0)
                                exit(128);
                        ret = reset_tree(new_tree,

diff --git a/merge-recursive.c b/merge-recursive.c
index 2a254d5563e16539ec39ecf9443e8256913dc802..4ce783dbfa3ad7908497aba33b664c039c45d632 100644 (file)
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -3623,16 +3623,16 @@ static void merge_finalize(struct merge_options *opt)
 int merge_trees(struct merge_options *opt,
                struct tree *head,
                struct tree *merge,
-               struct tree *common,
-               struct tree **result)
+               struct tree *common)
 {
        int clean;
+       struct tree *ignored;
 
        assert(opt->ancestor != NULL);
 
        if (merge_start(opt, head))
                return -1;
-       clean = merge_trees_internal(opt, head, merge, common, result);
+       clean = merge_trees_internal(opt, head, merge, common, &ignored);
        merge_finalize(opt);
 
        return clean;

diff --git a/merge-recursive.h b/merge-recursive.h
index f1b6ef38ae1c91964beba094a50a9dd16a211cfc..18012fff9dd7cc7d8ff3902974a3cd5ebcc1907c 100644 (file)
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -74,19 +74,31 @@ static inline int merge_detect_rename(struct merge_options *o)
                o->diff_detect_rename >= 0 ? o->diff_detect_rename : 1;
 }
 
-/* merge_trees() but with recursive ancestor consolidation */
+/*
+ * merge_recursive is like merge_trees() but with recursive ancestor
+ * consolidation, and when successful, it creates an actual commit
+ * and writes its address to *result.
+ *
+ * NOTE: empirically, about a decade ago it was determined that with more
+ *       than two merge bases, optimal behavior was found when the
+ *       ancestors were passed in the order of oldest merge base to newest
+ *       one.  Also, ancestors will be consumed (emptied) so make a copy if
+ *       you need it.
+ */
 int merge_recursive(struct merge_options *o,
                    struct commit *h1,
                    struct commit *h2,
                    struct commit_list *ancestors,
                    struct commit **result);
 
-/* rename-detecting three-way merge, no recursion */
+/*
+ * rename-detecting three-way merge, no recursion; result of merge is written
+ * to opt->repo->index.
+ */
 int merge_trees(struct merge_options *o,
                struct tree *head,
                struct tree *merge,
-               struct tree *common,
-               struct tree **result);
+               struct tree *common);
 
 /*
  * "git-merge-recursive" can be fed trees; wrap them into

diff --git a/sequencer.c b/sequencer.c
index 34ebf8ed94ad7d8df6773337d31ff7d9c2c84c4a..c4ed30f1b41a7212336c6832ec04588b4b535aae 100644 (file)
--- a/sequencer.c
+++ b/sequencer.c
@@ -586,7 +586,7 @@ static int do_recursive_merge(struct repository *r,
                              struct replay_opts *opts)
 {
        struct merge_options o;
-       struct tree *result, *next_tree, *base_tree, *head_tree;
+       struct tree *next_tree, *base_tree, *head_tree;
        int clean;
        char **xopt;
        struct lock_file index_lock = LOCK_INIT;
@@ -613,7 +613,7 @@ static int do_recursive_merge(struct repository *r,
 
        clean = merge_trees(&o,
                            head_tree,
-                           next_tree, base_tree, &result);
+                           next_tree, base_tree);
        if (is_rebase_i(opts) && clean <= 0)
                fputs(o.obuf.buf, stdout);
        strbuf_release(&o.obuf);