Merge branch 'jk/push-delete-ref-error-message'

The error message from "git push $there :bogo" mentioned we tried
and failed to guess what ref is being deleted based on the LHS of
the refspec, which we don't.

# By Jeff King
* jk/push-delete-ref-error-message:
push: don't guess at qualifying remote refs on deletion

diff --combined remote.c
index 6833538829e1d3e5fe4a525a1b44cbebd9f96efb,6b07e580aeebe6d5f8915fa5d8f1237413326f15..04fd9ea4bd2f99003c9c5abb7bbbad7dafca3937
--- 1/remote.c
--- 2/remote.c
+++ b/remote.c
@@@ -7,7 -7,6 +7,7 @@@
  #include "dir.h"
  #include "tag.h"
  #include "string-list.h"
 +#include "mergesort.h"
  
  enum map_direction { FROM_SRC, FROM_DST };
  
@@@ -919,27 -918,6 +919,27 @@@ void free_refs(struct ref *ref
        }
  }
  
 +int ref_compare_name(const void *va, const void *vb)
 +{
 +      const struct ref *a = va, *b = vb;
 +      return strcmp(a->name, b->name);
 +}
 +
 +static void *ref_list_get_next(const void *a)
 +{
 +      return ((const struct ref *)a)->next;
 +}
 +
 +static void ref_list_set_next(void *a, void *next)
 +{
 +      ((struct ref *)a)->next = next;
 +}
 +
 +void sort_ref_list(struct ref **l, int (*cmp)(const void *, const void *))
 +{
 +      *l = llist_mergesort(*l, ref_list_get_next, ref_list_set_next, cmp);
 +}
 +
  static int count_refspec_match(const char *pattern,
                               struct ref *refs,
                               struct ref **matched_ref)
@@@ -1100,6 -1078,9 +1100,9 @@@ static int match_explicit(struct ref *s
        case 0:
                if (!memcmp(dst_value, "refs/", 5))
                        matched_dst = make_linked_ref(dst_value, dst_tail);
+               else if (is_null_sha1(matched_src->new_sha1))
+                       error("unable to delete '%s': remote ref does not exist",
+                             dst_value);
                else if ((dst_guess = guess_ref(dst_value, matched_src)))
                        matched_dst = make_linked_ref(dst_guess, dst_tail);
                else