sha1_file: refactor read_object

diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
index 326f88b6576d6c02e9a0bcecb5a0b402bb257372..492245f4280cdda6a8d9baa85ed943f5b245bf62 100644 (file)
--- a/builtin/diff-tree.c
+++ b/builtin/diff-tree.c
@@ -9,7 +9,7 @@ static struct rev_info log_tree_opt;
 
 static int diff_tree_commit_sha1(const struct object_id *oid)
 {
-       struct commit *commit = lookup_commit_reference(oid->hash);
+       struct commit *commit = lookup_commit_reference(oid);
        if (!commit)
                return -1;
        return log_tree_commit(&log_tree_opt, commit);
@@ -23,7 +23,7 @@ static int stdin_diff_commit(struct commit *commit, const char *p)
 
        /* Graft the fake parents locally to the commit */
        while (isspace(*p++) && !parse_oid_hex(p, &oid, &p)) {
-               struct commit *parent = lookup_commit(oid.hash);
+               struct commit *parent = lookup_commit(&oid);
                if (!pptr) {
                        /* Free the real parent list */
                        free_commit_list(commit->parents);
@@ -44,7 +44,7 @@ static int stdin_diff_trees(struct tree *tree1, const char *p)
        struct tree *tree2;
        if (!isspace(*p++) || parse_oid_hex(p, &oid, &p) || *p)
                return error("Need exactly two trees, separated by a space");
-       tree2 = lookup_tree(oid.hash);
+       tree2 = lookup_tree(&oid);
        if (!tree2 || parse_tree(tree2))
                return -1;
        printf("%s %s\n", oid_to_hex(&tree1->object.oid),
@@ -67,7 +67,7 @@ static int diff_tree_stdin(char *line)
        line[len-1] = 0;
        if (parse_oid_hex(line, &oid, &p))
                return -1;
-       obj = parse_object(oid.hash);
+       obj = parse_object(&oid);
        if (!obj)
                return -1;
        if (obj->type == OBJ_COMMIT)
@@ -105,9 +105,9 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
        struct setup_revision_opt s_r_opt;
        int read_stdin = 0;
 
+       git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
        init_revisions(opt, prefix);
        gitmodules_config();
-       git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
        opt->abbrev = 0;
        opt->diff = 1;
        opt->disable_stdin = 1;
@@ -128,9 +128,11 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
        }
 
        /*
-        * NOTE! We expect "a ^b" to be equal to "a..b", so we
-        * reverse the order of the objects if the second one
-        * is marked UNINTERESTING.
+        * NOTE!  We expect "a..b" to expand to "^a b" but it is
+        * perfectly valid for revision range parser to yield "b ^a",
+        * which means the same thing. If we get the latter, i.e. the
+        * second one is marked UNINTERESTING, we recover the original
+        * order the user gave, i.e. "a..b", by swapping the trees.
         */
        nr_sha1 = opt->pending.nr;
        switch (nr_sha1) {