range-diff: consistently validate the arguments

This patch lets `range-diff` validate the arguments not only when
invoked with one or two arguments, but also in the code path where three
arguments are handled.

While at it, we now use `usage_msg_opt*()` consistently.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/range-diff.c b/builtin/range-diff.c
index f8d3869d357a837a448764e71f2196ba4f7eb4bf..71319ed1d840cfc37ac3766339bedee649136619 100644 (file)
--- a/builtin/range-diff.c
+++ b/builtin/range-diff.c
@@ -40,6 +40,7 @@ int cmd_range_diff(int argc, const char **argv, const char *prefix)
        struct option *options;
        int res = 0;
        struct strbuf range1 = STRBUF_INIT, range2 = STRBUF_INIT;
+       struct object_id oid;
 
        git_config(git_diff_ui_config, NULL);
 
@@ -56,24 +57,41 @@ int cmd_range_diff(int argc, const char **argv, const char *prefix)
                diffopt.use_color = 1;
 
        if (argc == 3) {
+               if (get_oid_committish(argv[0], &oid))
+                       usage_msg_optf(_("not a revision: '%s'"),
+                                      builtin_range_diff_usage, options,
+                                      argv[0]);
+               else if (get_oid_committish(argv[1], &oid))
+                       usage_msg_optf(_("not a revision: '%s'"),
+                                      builtin_range_diff_usage, options,
+                                      argv[1]);
+               else if (get_oid_committish(argv[2], &oid))
+                       usage_msg_optf(_("not a revision: '%s'"),
+                                      builtin_range_diff_usage, options,
+                                      argv[2]);
+
                strbuf_addf(&range1, "%s..%s", argv[0], argv[1]);
                strbuf_addf(&range2, "%s..%s", argv[0], argv[2]);
        } else if (argc == 2) {
                if (!is_range_diff_range(argv[0]))
-                       die(_("not a commit range: '%s'"), argv[0]);
-               strbuf_addstr(&range1, argv[0]);
+                       usage_msg_optf(_("not a commit range: '%s'"),
+                                      builtin_range_diff_usage, options,
+                                      argv[0]);
+               else if (!is_range_diff_range(argv[1]))
+                       usage_msg_optf(_("not a commit range: '%s'"),
+                                      builtin_range_diff_usage, options,
+                                      argv[1]);
 
-               if (!is_range_diff_range(argv[1]))
-                       die(_("not a commit range: '%s'"), argv[1]);
+               strbuf_addstr(&range1, argv[0]);
                strbuf_addstr(&range2, argv[1]);
        } else if (argc == 1) {
                const char *b = strstr(argv[0], "..."), *a = argv[0];
                int a_len;
 
-               if (!b) {
-                       error(_("single arg format must be symmetric range"));
-                       usage_with_options(builtin_range_diff_usage, options);
-               }
+               if (!b)
+                       usage_msg_optf(_("not a symmetric range: '%s'"),
+                                      builtin_range_diff_usage, options,
+                                      argv[0]);
 
                a_len = (int)(b - a);
                if (!a_len) {
@@ -85,10 +103,9 @@ int cmd_range_diff(int argc, const char **argv, const char *prefix)
                        b = "HEAD";
                strbuf_addf(&range1, "%s..%.*s", b, a_len, a);
                strbuf_addf(&range2, "%.*s..%s", a_len, a, b);
-       } else {
-               error(_("need two commit ranges"));
-               usage_with_options(builtin_range_diff_usage, options);
-       }
+       } else
+               usage_msg_opt(_("need two commit ranges"),
+                             builtin_range_diff_usage, options);
        FREE_AND_NULL(options);
 
        range_diff_opts.dual_color = simple_color < 1;