Merge branch 'jk/negative-hiderefs'

A negative !ref entry in multi-value transfer.hideRefs
configuration can be used to say "don't hide this one".

* jk/negative-hiderefs:
  refs: support negative transfer.hideRefs
  docs/config.txt: reorder hideRefs config

Documentation/config.txt

@@ -2313,13 +2313,10 @@ receive.denyNonFastForwards::
 	set when initializing a shared repository.
 
 receive.hideRefs::
-	String(s) `receive-pack` uses to decide which refs to omit
-	from its initial advertisement.  Use more than one
-	definitions to specify multiple prefix strings. A ref that
-	are under the hierarchies listed on the value of this
-	variable is excluded, and is hidden when responding to `git
-	push`, and an attempt to update or delete a hidden ref by
-	`git push` is rejected.
+	This variable is the same as `transfer.hideRefs`, but applies
+	only to `receive-pack` (and so affects pushes, but not fetches).
+	An attempt to update or delete a hidden ref by `git push` is
+	rejected.
 
 receive.updateServerInfo::
 	If set to true, git-receive-pack will run git-update-server-info
@@ -2607,9 +2604,18 @@ transfer.fsckObjects::
 	Defaults to false.
 
 transfer.hideRefs::
-	This variable can be used to set both `receive.hideRefs`
-	and `uploadpack.hideRefs` at the same time to the same
-	values.  See entries for these other variables.
+	String(s) `receive-pack` and `upload-pack` use to decide which
+	refs to omit from their initial advertisements.  Use more than
+	one definition to specify multiple prefix strings. A ref that is
+	under the hierarchies listed in the value of this variable is
+	excluded, and is hidden when responding to `git push` or `git
+	fetch`.  See `receive.hideRefs` and `uploadpack.hideRefs` for
+	program-specific versions of this config.
++
+You may also include a `!` in front of the ref name to negate the entry,
+explicitly exposing it, even if an earlier entry marked it as hidden.
+If you have multiple hideRefs values, later entries override earlier ones
+(and entries in more-specific config files override less-specific ones).
 
 transfer.unpackLimit::
 	When `fetch.unpackLimit` or `receive.unpackLimit` are
@@ -2624,13 +2630,10 @@ uploadarchive.allowUnreachable::
 	`false`.
 
 uploadpack.hideRefs::
-	String(s) `upload-pack` uses to decide which refs to omit
-	from its initial advertisement.  Use more than one
-	definitions to specify multiple prefix strings. A ref that
-	are under the hierarchies listed on the value of this
-	variable is excluded, and is hidden from `git ls-remote`,
-	`git fetch`, etc.  An attempt to fetch a hidden ref by `git
-	fetch` will fail.  See also `uploadpack.allowTipSHA1InWant`.
+	This variable is the same as `transfer.hideRefs`, but applies
+	only to `upload-pack` (and so affects only fetches, not pushes).
+	An attempt to fetch a hidden ref by `git fetch` will fail.  See
+	also `uploadpack.allowTipSHA1InWant`.
 
 uploadpack.allowTipSHA1InWant::
 	When `uploadpack.hideRefs` is in effect, allow `upload-pack`

refs.c

@@ -4371,17 +4371,25 @@ int parse_hide_refs_config(const char *var, const char *value, const char *secti
 
 int ref_is_hidden(const char *refname)
 {
-	struct string_list_item *item;
+	int i;
 
 	if (!hide_refs)
 		return 0;
-	for_each_string_list_item(item, hide_refs) {
+	for (i = hide_refs->nr - 1; i >= 0; i--) {
+		const char *match = hide_refs->items[i].string;
+		int neg = 0;
 		int len;
-		if (!starts_with(refname, item->string))
+
+		if (*match == '!') {
+			neg = 1;
+			match++;
+		}
+
+		if (!starts_with(refname, match))
 			continue;
-		len = strlen(item->string);
+		len = strlen(match);
 		if (!refname[len] || refname[len] == '/')
-			return 1;
+			return !neg;
 	}
 	return 0;
 }

t/t5512-ls-remote.sh

@@ -128,6 +128,11 @@ test_expect_success 'Report match with --exit-code' '
 	test_cmp expect actual
 '
 
+test_expect_success 'set up some extra tags for ref hiding' '
+	git tag magic/one &&
+	git tag magic/two
+'
+
 for configsection in transfer uploadpack
 do
 	test_expect_success "Hide some refs with $configsection.hiderefs" '
@@ -138,6 +143,24 @@ do
 		sed -e "/	refs\/tags\//d" >expect &&
 		test_cmp expect actual
 	'
+
+	test_expect_success "Override hiding of $configsection.hiderefs" '
+		test_when_finished "test_unconfig $configsection.hiderefs" &&
+		git config --add $configsection.hiderefs refs/tags &&
+		git config --add $configsection.hiderefs "!refs/tags/magic" &&
+		git config --add $configsection.hiderefs refs/tags/magic/one &&
+		git ls-remote . >actual &&
+		grep refs/tags/magic/two actual &&
+		! grep refs/tags/magic/one actual
+	'
+
 done
 
+test_expect_success 'overrides work between mixed transfer/upload-pack hideRefs' '
+	test_config uploadpack.hiderefs refs/tags &&
+	test_config transfer.hiderefs "!refs/tags/magic" &&
+	git ls-remote . >actual &&
+	grep refs/tags/magic actual
+'
+
 test_done