Merge branch 'maint'

* maint:
show-branch: fix segfault when showbranch.default exists

diff --combined builtin-show-branch.c
index 3510a86e38d2821880060d4faa554c016a9f95e2,baec9ed56f4098183445b85cdd1b2789d487d6fe..be95930b783f47ade274e281227844e795729f5a
--- 1/builtin-show-branch.c
--- 2/builtin-show-branch.c
+++ b/builtin-show-branch.c
@@@ -6,8 -6,8 +6,8 @@@
  #include "parse-options.h"
  
  static const char* show_branch_usage[] = {
 -    "git show-branch [--sparse] [--current] [--all] [--remotes] [--topo-order] [--more=count | --list | --independent | --merge-base] [--topics] [--color] [<refs>...]",
 -    "--reflog[=n[,b]] [--list] [--color] <branch>",
 +    "git show-branch [-a|--all] [-r|--remotes] [--topo-order | --date-order] [--current] [--color | --no-color] [--sparse] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] [--topics] [<rev> | <glob>]...",
 +    "git show-branch (-g|--reflog)[=<n>[,<base>]] [--list] [<ref>]",
      NULL
  };
  
@@@ -565,7 -565,15 +565,15 @@@ static int git_show_branch_config(cons
        if (!strcmp(var, "showbranch.default")) {
                if (!value)
                        return config_error_nonbool(var);
-               if (default_alloc <= default_num + 1) {
+               /*
+                * default_arg is now passed to parse_options(), so we need to
+                * mimick the real argv a bit better.
+                */
+               if (!default_num) {
+                       default_alloc = 20;
+                       default_arg = xcalloc(default_alloc, sizeof(*default_arg));
+                       default_arg[default_num++] = "show-branch";
+               } else if (default_alloc <= default_num + 1) {
                        default_alloc = default_alloc * 3 / 2 + 20;
                        default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
                }
@@@ -665,7 -673,7 +673,7 @@@ int cmd_show_branch(int ac, const char 
                OPT_BOOLEAN(0, "sha1-name", &sha1_name,
                            "name commits with their object names"),
                OPT_BOOLEAN(0, "merge-base", &merge_base,
 -                          "act like git merge-base -a"),
 +                          "show possible merge bases"),
                OPT_BOOLEAN(0, "independent", &independent,
                            "show refs unreachable from any other ref"),
                OPT_BOOLEAN(0, "topo-order", &lifo,
@@@ -692,8 -700,8 +700,8 @@@
  
        /* If nothing is specified, try the default first */
        if (ac == 1 && default_num) {
-               ac = default_num + 1;
-               av = default_arg - 1; /* ick; we would not address av[0] */
+               ac = default_num;
+               av = default_arg;
        }
  
        ac = parse_options(ac, av, prefix, builtin_show_branch_options,