Merge branch 'jc/merge-refuse-new-root'

"git pull" has been taught to pass --allow-unrelated-histories
option to underlying "git merge".

* jc/merge-refuse-new-root:
pull: pass --allow-unrelated-histories to "git merge"
t3033: avoid 'ambiguous refs' warning

diff --combined builtin/pull.c
index d98f481d31535fd63773fd987b5a252901ca2ac0,797932d0b029ca8156822ec8f1b487b1199b648a..596b92fc5699b92bf2e2b9e3f53a6e9925874a66
--- 1/builtin/pull.c
--- 2/builtin/pull.c
+++ b/builtin/pull.c
@@@ -22,8 -22,7 +22,8 @@@ enum rebase_type 
        REBASE_INVALID = -1,
        REBASE_FALSE = 0,
        REBASE_TRUE,
 -      REBASE_PRESERVE
 +      REBASE_PRESERVE,
 +      REBASE_INTERACTIVE
  };
  
  /**
@@@ -43,8 -42,6 +43,8 @@@ static enum rebase_type parse_config_re
                return REBASE_TRUE;
        else if (!strcmp(value, "preserve"))
                return REBASE_PRESERVE;
 +      else if (!strcmp(value, "interactive"))
 +              return REBASE_INTERACTIVE;
  
        if (fatal)
                die(_("Invalid value for %s: %s"), key, value);
@@@ -86,11 -83,10 +86,12 @@@ static char *opt_commit
  static char *opt_edit;
  static char *opt_ff;
  static char *opt_verify_signatures;
 +static int opt_autostash = -1;
 +static int config_autostash;
  static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
  static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
  static char *opt_gpg_sign;
+ static int opt_allow_unrelated_histories;
  
  /* Options passed to git-fetch */
  static char *opt_all;
@@@ -100,7 -96,6 +101,7 @@@ static int opt_force
  static char *opt_tags;
  static char *opt_prune;
  static char *opt_recurse_submodules;
 +static char *max_children;
  static int opt_dry_run;
  static char *opt_keep;
  static char *opt_depth;
@@@ -118,7 -113,7 +119,7 @@@ static struct option pull_options[] = 
        /* Options passed to git-merge or git-rebase */
        OPT_GROUP(N_("Options related to merging")),
        { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
 -        "false|true|preserve",
 +        "false|true|preserve|interactive",
          N_("incorporate changes by rebasing rather than merging"),
          PARSE_OPT_OPTARG, parse_opt_rebase },
        OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
@@@ -151,8 -146,6 +152,8 @@@
        OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
                N_("verify that the named commit has a valid GPG signature"),
                PARSE_OPT_NOARG),
 +      OPT_BOOL(0, "autostash", &opt_autostash,
 +              N_("automatically stash/stash pop before and after rebase")),
        OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
                N_("merge strategy to use"),
                0),
@@@ -163,6 -156,9 +164,9 @@@
        OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
                N_("GPG sign commit"),
                PARSE_OPT_OPTARG),
+       OPT_SET_INT(0, "allow-unrelated-histories",
+                   &opt_allow_unrelated_histories,
+                   N_("allow merging unrelated histories"), 1),
  
        /* Options passed to git-fetch */
        OPT_GROUP(N_("Options related to fetching")),
@@@ -186,9 -182,6 +190,9 @@@
                N_("on-demand"),
                N_("control recursive fetching of submodules"),
                PARSE_OPT_OPTARG),
 +      OPT_PASSTHRU('j', "jobs", &max_children, N_("n"),
 +              N_("number of submodules pulled in parallel"),
 +              PARSE_OPT_OPTARG),
        OPT_BOOL(0, "dry-run", &opt_dry_run,
                N_("dry run")),
        OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
@@@ -309,18 -302,6 +313,18 @@@ static enum rebase_type config_get_reba
        return REBASE_FALSE;
  }
  
 +/**
 + * Read config variables.
 + */
 +static int git_pull_config(const char *var, const char *value, void *cb)
 +{
 +      if (!strcmp(var, "rebase.autostash")) {
 +              config_autostash = git_config_bool(var, value);
 +              return 0;
 +      }
 +      return git_default_config(var, value, cb);
 +}
 +
  /**
   * Returns 1 if there are unstaged changes, 0 otherwise.
   */
@@@ -401,7 -382,7 +405,7 @@@ static void get_merge_heads(struct sha1
  
        if (!(fp = fopen(filename, "r")))
                die_errno(_("could not open '%s' for reading"), filename);
 -      while (strbuf_getline(&sb, fp, '\n') != EOF) {
 +      while (strbuf_getline_lf(&sb, fp) != EOF) {
                if (get_sha1_hex(sb.buf, sha1))
                        continue;  /* invalid line: does not start with SHA1 */
                if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
@@@ -548,8 -529,6 +552,8 @@@ static int run_fetch(const char *repo, 
                argv_array_push(&args, opt_prune);
        if (opt_recurse_submodules)
                argv_array_push(&args, opt_recurse_submodules);
 +      if (max_children)
 +              argv_array_push(&args, max_children);
        if (opt_dry_run)
                argv_array_push(&args, "--dry-run");
        if (opt_keep)
@@@ -628,6 -607,8 +632,8 @@@ static int run_merge(void
        argv_array_pushv(&args, opt_strategy_opts.argv);
        if (opt_gpg_sign)
                argv_array_push(&args, opt_gpg_sign);
+       if (opt_allow_unrelated_histories > 0)
+               argv_array_push(&args, "--allow-unrelated-histories");
  
        argv_array_push(&args, "FETCH_HEAD");
        ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
@@@ -797,18 -778,12 +803,18 @@@ static int run_rebase(const unsigned ch
        /* Options passed to git-rebase */
        if (opt_rebase == REBASE_PRESERVE)
                argv_array_push(&args, "--preserve-merges");
 +      else if (opt_rebase == REBASE_INTERACTIVE)
 +              argv_array_push(&args, "--interactive");
        if (opt_diffstat)
                argv_array_push(&args, opt_diffstat);
        argv_array_pushv(&args, opt_strategies.argv);
        argv_array_pushv(&args, opt_strategy_opts.argv);
        if (opt_gpg_sign)
                argv_array_push(&args, opt_gpg_sign);
 +      if (opt_autostash == 0)
 +              argv_array_push(&args, "--no-autostash");
 +      else if (opt_autostash == 1)
 +              argv_array_push(&args, "--autostash");
  
        argv_array_push(&args, "--onto");
        argv_array_push(&args, sha1_to_hex(merge_head));
@@@ -843,7 -818,7 +849,7 @@@ int cmd_pull(int argc, const char **arg
        if (opt_rebase < 0)
                opt_rebase = config_get_rebase();
  
 -      git_config(git_default_config, NULL);
 +      git_config(git_pull_config, NULL);
  
        if (read_cache_unmerged())
                die_resolve_conflict("Pull");
@@@ -854,17 -829,13 +860,17 @@@
        if (get_sha1("HEAD", orig_head))
                hashclr(orig_head);
  
 +      if (!opt_rebase && opt_autostash != -1)
 +              die(_("--[no-]autostash option is only valid with --rebase."));
 +
        if (opt_rebase) {
 -              int autostash = 0;
 +              int autostash = config_autostash;
 +              if (opt_autostash != -1)
 +                      autostash = opt_autostash;
  
                if (is_null_sha1(orig_head) && !is_cache_unborn())
                        die(_("Updating an unborn branch with changes added to the index."));
  
 -              git_config_get_bool("rebase.autostash", &autostash);
                if (!autostash)
                        die_on_unclean_work_tree(prefix);