transport-helper: clarify *:* refspec

The *:* refspec doesn't work, and never has, clarify the code and
documentation to reflect that. This in effect reverts commit 9e7673e
(gitremote-helpers(1): clarify refspec behaviour).

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/gitremote-helpers.txt

@@ -174,8 +174,8 @@ ref.
 This capability can be advertised multiple times.  The first
 applicable refspec takes precedence.  The left-hand of refspecs
 advertised with this capability must cover all refs reported by
-the list command.  If a helper does not need a specific 'refspec'
-capability then it should advertise `refspec *:*`.
+the list command.  If no 'refspec' capability is advertised,
+there is an implied `refspec *:*`.
 
 'bidi-import'::
 	This modifies the 'import' capability.

t/t5801-remote-helpers.sh

@@ -120,21 +120,6 @@ test_expect_failure 'pushing without refspecs' '
 	compare_refs local2 HEAD server HEAD
 '
 
-test_expect_success 'pulling with straight refspec' '
-	(cd local2 &&
-	GIT_REMOTE_TESTGIT_REFSPEC="*:*" git pull) &&
-	compare_refs local2 HEAD server HEAD
-'
-
-test_expect_failure 'pushing with straight refspec' '
-	test_when_finished "(cd local2 && git reset --hard origin)" &&
-	(cd local2 &&
-	echo content >>file &&
-	git commit -a -m eleven &&
-	GIT_REMOTE_TESTGIT_REFSPEC="*:*" git push) &&
-	compare_refs local2 HEAD server HEAD
-'
-
 test_expect_success 'pulling without marks' '
 	(cd local2 &&
 	GIT_REMOTE_TESTGIT_NO_MARKS=1 git pull) &&

transport-helper.c

@@ -469,7 +469,7 @@ static int fetch_with_import(struct transport *transport,
 	 * were fetching.
 	 *
 	 * (If no "refspec" capability was specified, for historical
-	 * reasons we default to *:*.)
+	 * reasons we default to the equivalent of *:*.)
 	 *
 	 * Store the result in to_fetch[i].old_sha1.  Callers such
 	 * as "git fetch" can use the value to write feedback to the