blame: dwim "blame --reverse OLD" as "blame --reverse OLD.."

diff --git a/builtin/blame.c b/builtin/blame.c
index 55bf5fae9d5d6ea6c4e058e50d9353e77e09b34b..574b47dd55b97577b701f61a0aab09e8185e665a 100644 (file)
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -466,13 +466,11 @@ static void queue_blames(struct scoreboard *sb, struct origin *porigin,
 static struct origin *make_origin(struct commit *commit, const char *path)
 {
        struct origin *o;
-       size_t pathlen = strlen(path) + 1;
-       o = xcalloc(1, sizeof(*o) + pathlen);
+       FLEX_ALLOC_STR(o, path, path);
        o->commit = commit;
        o->refcnt = 1;
        o->next = commit->util;
        commit->util = o;
-       memcpy(o->path, path, pathlen); /* includes NUL */
        return o;
 }
 
@@ -2059,7 +2057,8 @@ static int prepare_lines(struct scoreboard *sb)
        for (p = buf; p < end; p = get_next_line(p, end))
                num++;
 
-       sb->lineno = lineno = xmalloc(sizeof(*sb->lineno) * (num + 1));
+       ALLOC_ARRAY(sb->lineno, num + 1);
+       lineno = sb->lineno;
 
        for (p = buf; p < end; p = get_next_line(p, end))
                *lineno++ = p - buf;
@@ -2308,6 +2307,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
        unsigned mode;
        struct strbuf msg = STRBUF_INIT;
 
+       read_cache();
        time(&now);
        commit = alloc_commit_node();
        commit->object.parsed = 1;
@@ -2447,6 +2447,41 @@ static char *prepare_final(struct scoreboard *sb)
        return xstrdup_or_null(name);
 }
 
+static const char *dwim_reverse_initial(struct scoreboard *sb)
+{
+       /*
+        * DWIM "git blame --reverse ONE -- PATH" as
+        * "git blame --reverse ONE..HEAD -- PATH" but only do so
+        * when it makes sense.
+        */
+       struct object *obj;
+       struct commit *head_commit;
+       unsigned char head_sha1[20];
+
+       if (sb->revs->pending.nr != 1)
+               return NULL;
+
+       /* Is that sole rev a committish? */
+       obj = sb->revs->pending.objects[0].item;
+       obj = deref_tag(obj, NULL, 0);
+       if (obj->type != OBJ_COMMIT)
+               return NULL;
+
+       /* Do we have HEAD? */
+       if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
+               return NULL;
+       head_commit = lookup_commit_reference_gently(head_sha1, 1);
+       if (!head_commit)
+               return NULL;
+
+       /* Turn "ONE" into "ONE..HEAD" then */
+       obj->flags |= UNINTERESTING;
+       add_pending_object(sb->revs, &head_commit->object, "HEAD");
+
+       sb->final = (struct commit *)obj;
+       return sb->revs->pending.objects[0].name;
+}
+
 static char *prepare_initial(struct scoreboard *sb)
 {
        int i;
@@ -2466,14 +2501,17 @@ static char *prepare_initial(struct scoreboard *sb)
                if (obj->type != OBJ_COMMIT)
                        die("Non commit %s?", revs->pending.objects[i].name);
                if (sb->final)
-                       die("More than one commit to dig down to %s and %s?",
+                       die("More than one commit to dig up from, %s and %s?",
                            revs->pending.objects[i].name,
                            final_commit_name);
                sb->final = (struct commit *) obj;
                final_commit_name = revs->pending.objects[i].name;
        }
+
+       if (!final_commit_name)
+               final_commit_name = dwim_reverse_initial(sb);
        if (!final_commit_name)
-               die("No commit to dig down to?");
+               die("No commit to dig up from?");
        return xstrdup(final_commit_name);
 }