builtin-help: fallback to GIT_MAN_VIEWER before man

diff --git a/builtin-diff-tree.c b/builtin-diff-tree.c
index 24cb2d7f84064d7833fa04f33aeca6eafc8b931d..1138c2da733bfe2730bbcb95d2a281de12595bde 100644 (file)
--- a/builtin-diff-tree.c
+++ b/builtin-diff-tree.c
@@ -14,20 +14,10 @@ static int diff_tree_commit_sha1(const unsigned char *sha1)
        return log_tree_commit(&log_tree_opt, commit);
 }
 
-static int diff_tree_stdin(char *line)
+/* Diff one or more commits. */
+static int stdin_diff_commit(struct commit *commit, char *line, int len)
 {
-       int len = strlen(line);
        unsigned char sha1[20];
-       struct commit *commit;
-
-       if (!len || line[len-1] != '\n')
-               return -1;
-       line[len-1] = 0;
-       if (get_sha1_hex(line, sha1))
-               return -1;
-       commit = lookup_commit(sha1);
-       if (!commit || parse_commit(commit))
-               return -1;
        if (isspace(line[40]) && !get_sha1_hex(line+41, sha1)) {
                /* Graft the fake parents locally to the commit */
                int pos = 41;
@@ -52,8 +42,50 @@ static int diff_tree_stdin(char *line)
        return log_tree_commit(&log_tree_opt, commit);
 }
 
+/* Diff two trees. */
+static int stdin_diff_trees(struct tree *tree1, char *line, int len)
+{
+       unsigned char sha1[20];
+       struct tree *tree2;
+       if (len != 82 || !isspace(line[40]) || get_sha1_hex(line + 41, sha1))
+               return error("Need exactly two trees, separated by a space");
+       tree2 = lookup_tree(sha1);
+       if (!tree2 || parse_tree(tree2))
+               return -1;
+       printf("%s %s\n", sha1_to_hex(tree1->object.sha1),
+                         sha1_to_hex(tree2->object.sha1));
+       diff_tree_sha1(tree1->object.sha1, tree2->object.sha1,
+                      "", &log_tree_opt.diffopt);
+       log_tree_diff_flush(&log_tree_opt);
+       return 0;
+}
+
+static int diff_tree_stdin(char *line)
+{
+       int len = strlen(line);
+       unsigned char sha1[20];
+       struct object *obj;
+
+       if (!len || line[len-1] != '\n')
+               return -1;
+       line[len-1] = 0;
+       if (get_sha1_hex(line, sha1))
+               return -1;
+       obj = lookup_object(sha1);
+       obj = obj ? obj : parse_object(sha1);
+       if (!obj)
+               return -1;
+       if (obj->type == OBJ_COMMIT)
+               return stdin_diff_commit((struct commit *)obj, line, len);
+       if (obj->type == OBJ_TREE)
+               return stdin_diff_trees((struct tree *)obj, line, len);
+       error("Object %s is a %s, not a commit or tree",
+             sha1_to_hex(sha1), typename(obj->type));
+       return -1;
+}
+
 static const char diff_tree_usage[] =
-"git-diff-tree [--stdin] [-m] [-c] [--cc] [-s] [-v] [--pretty] [-t] [-r] [--root] "
+"git diff-tree [--stdin] [-m] [-c] [--cc] [-s] [-v] [--pretty] [-t] [-r] [--root] "
 "[<common diff options>] <tree-ish> [<tree-ish>] [<path>...]\n"
 "  -r            diff recursively\n"
 "  --root        include the initial commit as diff against /dev/null\n"
@@ -68,7 +100,7 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
        int read_stdin = 0;
 
        init_revisions(opt, prefix);
-       git_config(git_default_config); /* no "diff" UI options */
+       git_config(git_diff_basic_config, NULL); /* no "diff" UI options */
        nr_sha1 = 0;
        opt->abbrev = 0;
        opt->diff = 1;
@@ -117,21 +149,21 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
                break;
        }
 
-       if (!read_stdin)
-               return 0;
+       if (read_stdin) {
+               if (opt->diffopt.detect_rename)
+                       opt->diffopt.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
+                                              DIFF_SETUP_USE_CACHE);
+               while (fgets(line, sizeof(line), stdin)) {
+                       unsigned char sha1[20];
 
-       if (opt->diffopt.detect_rename)
-               opt->diffopt.setup |= (DIFF_SETUP_USE_SIZE_CACHE |
-                                      DIFF_SETUP_USE_CACHE);
-       while (fgets(line, sizeof(line), stdin)) {
-               unsigned char sha1[20];
-
-               if (get_sha1_hex(line, sha1)) {
-                       fputs(line, stdout);
-                       fflush(stdout);
+                       if (get_sha1_hex(line, sha1)) {
+                               fputs(line, stdout);
+                               fflush(stdout);
+                       }
+                       else
+                               diff_tree_stdin(line);
                }
-               else
-                       diff_tree_stdin(line);
        }
-       return 0;
+
+       return diff_result_code(&opt->diffopt, 0);
 }