tree-diff: drop list-tail argument to diff_tree_paths()

The internals of the path diffing code, including ll_diff_tree_paths(),
all take an extra combine_diff_path parameter which they use as the tail
of a list of results, appending any new entries to it.

The public-facing diff_tree_paths() takes the same argument, but it just
makes the callers more awkward. They always start with a clean list, and
have to set up a fake head struct to pass in.

Let's keep the public API clean by always returning a new list. That
keeps the fake struct as an implementation detail of tree-diff.c.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/combine-diff.c b/combine-diff.c
index f21e1f58ba9c461bb012aaecbb9cae2d2356838d..9527f3160d8c2269c4aa3cbe071112ca476c73e5 100644 (file)
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -1428,22 +1428,19 @@ static struct combine_diff_path *find_paths_multitree(
 {
        int i, nparent = parents->nr;
        const struct object_id **parents_oid;
-       struct combine_diff_path paths_head;
+       struct combine_diff_path *paths;
        struct strbuf base;
 
        ALLOC_ARRAY(parents_oid, nparent);
        for (i = 0; i < nparent; i++)
                parents_oid[i] = &parents->oid[i];
 
-       /* fake list head, so worker can assume it is non-NULL */
-       paths_head.next = NULL;
-
        strbuf_init(&base, PATH_MAX);
-       diff_tree_paths(&paths_head, oid, parents_oid, nparent, &base, opt);
+       paths = diff_tree_paths(oid, parents_oid, nparent, &base, opt);
 
        strbuf_release(&base);
        free(parents_oid);
-       return paths_head.next;
+       return paths;
 }
 
 static int match_objfind(struct combine_diff_path *path,

diff --git a/diff.h b/diff.h
index 32ad17fd38afa401ae538336adbcc068b137f810..7831ed1a2b1fd1993c77364ef24d5e0019281b64 100644 (file)
--- a/diff.h
+++ b/diff.h
@@ -462,7 +462,7 @@ const char *diff_line_prefix(struct diff_options *);
 extern const char mime_boundary_leader[];
 
 struct combine_diff_path *diff_tree_paths(
-       struct combine_diff_path *p, const struct object_id *oid,
+       const struct object_id *oid,
        const struct object_id **parents_oid, int nparent,
        struct strbuf *base, struct diff_options *opt);
 void diff_tree_oid(const struct object_id *old_oid,

diff --git a/tree-diff.c b/tree-diff.c
index 18e5a167169ab8201e1476473c6a3e50ae41dfd8..e99e40da1819550325d3677e564f862162c5a28b 100644 (file)
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -510,11 +510,14 @@ static struct combine_diff_path *ll_diff_tree_paths(
 }
 
 struct combine_diff_path *diff_tree_paths(
-       struct combine_diff_path *p, const struct object_id *oid,
+       const struct object_id *oid,
        const struct object_id **parents_oid, int nparent,
        struct strbuf *base, struct diff_options *opt)
 {
-       p = ll_diff_tree_paths(p, oid, parents_oid, nparent, base, opt, 0);
+       struct combine_diff_path head, *p;
+       /* fake list head, so worker can assume it is non-NULL */
+       head.next = NULL;
+       p = ll_diff_tree_paths(&head, oid, parents_oid, nparent, base, opt, 0);
        return p;
 }
 
@@ -631,14 +634,13 @@ static void ll_diff_tree_oid(const struct object_id *old_oid,
                             const struct object_id *new_oid,
                             struct strbuf *base, struct diff_options *opt)
 {
-       struct combine_diff_path phead, *p;
+       struct combine_diff_path *paths, *p;
        pathchange_fn_t pathchange_old = opt->pathchange;
 
-       phead.next = NULL;
        opt->pathchange = emit_diff_first_parent_only;
-       diff_tree_paths(&phead, new_oid, &old_oid, 1, base, opt);
+       paths = diff_tree_paths(new_oid, &old_oid, 1, base, opt);
 
-       for (p = phead.next; p;) {
+       for (p = paths; p;) {
                struct combine_diff_path *pprev = p;
                p = p->next;
                free(pprev);