Merge branch 'mh/get-remote-group-fix' into maint

An off-by-one error made "git remote" to mishandle a remote with a
single letter nickname.

* mh/get-remote-group-fix:
get_remote_group(): use skip_prefix()
get_remote_group(): eliminate superfluous call to strcspn()
get_remote_group(): rename local variable "space" to "wordlen"
get_remote_group(): handle remotes with single-character names

diff --combined builtin/fetch.c
index 8d5b2dba2bc4251a7c35bc6aa6ff260ea72b7455,262809c78725a2a7924f1f806f40bf1a7577df11..635bbdfc88ee17952e7992f1988a307b4afba7e2
--- 1/builtin/fetch.c
--- 2/builtin/fetch.c
+++ b/builtin/fetch.c
@@@ -179,15 -179,13 +179,15 @@@ static void add_merge_config(struct re
        }
  }
  
 -static int add_existing(const char *refname, const unsigned char *sha1,
 +static int add_existing(const char *refname, const struct object_id *oid,
                        int flag, void *cbdata)
  {
        struct string_list *list = (struct string_list *)cbdata;
        struct string_list_item *item = string_list_insert(list, refname);
 -      item->util = xmalloc(20);
 -      hashcpy(item->util, sha1);
 +      struct object_id *old_oid = xmalloc(sizeof(*old_oid));
 +
 +      oidcpy(old_oid, oid);
 +      item->util = old_oid;
        return 0;
  }
  
@@@ -417,10 -415,8 +417,10 @@@ static int s_update_ref(const char *act
  
        transaction = ref_transaction_begin(&err);
        if (!transaction ||
 -          ref_transaction_update(transaction, ref->name, ref->new_sha1,
 -                                 ref->old_sha1, 0, check_old, msg, &err))
 +          ref_transaction_update(transaction, ref->name,
 +                                 ref->new_sha1,
 +                                 check_old ? ref->old_sha1 : NULL,
 +                                 0, msg, &err))
                goto fail;
  
        ret = ref_transaction_commit(transaction, &err);
@@@ -590,8 -586,7 +590,8 @@@ static int store_updated_refs(const cha
        struct strbuf note = STRBUF_INIT;
        const char *what, *kind;
        struct ref *rm;
 -      char *url, *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
 +      char *url;
 +      const char *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
        int want_status;
  
        fp = fopen(filename, "a");
@@@ -825,7 -820,7 +825,7 @@@ static void check_not_current_branch(st
  
  static int truncate_fetch_head(void)
  {
 -      char *filename = git_path("FETCH_HEAD");
 +      const char *filename = git_path("FETCH_HEAD");
        FILE *fp = fopen(filename, "w");
  
        if (!fp)
@@@ -915,10 -910,9 +915,10 @@@ static int do_fetch(struct transport *t
                        struct string_list_item *peer_item =
                                string_list_lookup(&existing_refs,
                                                   rm->peer_ref->name);
 -                      if (peer_item)
 -                              hashcpy(rm->peer_ref->old_sha1,
 -                                      peer_item->util);
 +                      if (peer_item) {
 +                              struct object_id *old_oid = peer_item->util;
 +                              hashcpy(rm->peer_ref->old_sha1, old_oid->hash);
 +                      }
                }
        }
  
@@@ -979,17 -973,15 +979,15 @@@ static int get_remote_group(const char 
  {
        struct remote_group_data *g = priv;
  
-       if (starts_with(key, "remotes.") &&
-                       !strcmp(key + 8, g->name)) {
+       if (skip_prefix(key, "remotes.", &key) && !strcmp(key, g->name)) {
                /* split list by white space */
-               int space = strcspn(value, " \t\n");
                while (*value) {
-                       if (space > 1) {
+                       size_t wordlen = strcspn(value, " \t\n");
+ 
+                       if (wordlen >= 1)
                                string_list_append(g->list,
-                                                  xstrndup(value, space));
-                       }
-                       value += space + (value[space] != '\0');
-                       space = strcspn(value, " \t\n");
+                                                  xstrndup(value, wordlen));
+                       value += wordlen + (value[wordlen] != '\0');
                }
        }