Merge branch 'mk/http-backend-content-length'

The earlier attempt barfed when given a CONTENT_LENGTH that is
set to an empty string.  RFC 3875 is fairly clear that in this
case we should not read any message body, but we've been reading
through to the EOF in previous versions (which did not even pay
attention to the environment variable), so keep that behaviour for
now in this late update.

* mk/http-backend-content-length:
http-backend: allow empty CONTENT_LENGTH

diff --combined http-backend.c
index 88c38c834ba479447be8eb64f3bc5331cdb9ed49,a1230d7ead1a6a3c49c99a809b529a3a2b419043..458642ef72b879a2f53d6e1f8f192847ed814111
--- 1/http-backend.c
--- 2/http-backend.c
+++ b/http-backend.c
@@@ -353,7 -353,7 +353,7 @@@ static ssize_t get_content_length(void
        ssize_t val = -1;
        const char *str = getenv("CONTENT_LENGTH");
  
-       if (str && !git_parse_ssize_t(str, &val))
+       if (str && *str && !git_parse_ssize_t(str, &val))
                die("failed to parse CONTENT_LENGTH: %s", str);
        return val;
  }
@@@ -508,13 -508,13 +508,13 @@@ static int show_text_ref(const char *na
  {
        const char *name_nons = strip_namespace(name);
        struct strbuf *buf = cb_data;
 -      struct object *o = parse_object(oid);
 +      struct object *o = parse_object(the_repository, oid);
        if (!o)
                return 0;
  
        strbuf_addf(buf, "%s\t%s\n", oid_to_hex(oid), name_nons);
        if (o->type == OBJ_TAG) {
 -              o = deref_tag(o, name, 0);
 +              o = deref_tag(the_repository, o, name, 0);
                if (!o)
                        return 0;
                strbuf_addf(buf, "%s\t%s^{}\n", oid_to_hex(&o->oid),