Gather bugfix: support empty :vars.

* match.c (v_gather): Use getplist_f to distinguish the :vars
nil case just like v_collect does. A :vars nil gather could be
useful; it says none of the variables are strictly required.
In any case, it is not correct to treat :vars nil as if :vars
weren't there.

1 files changed, 5 insertions, 2 deletions

diff --git a/match.c b/match.c
index 3c78e651..22bb3fb5 100644
--- a/match.c
+++ b/match.c
@@ -2596,7 +2596,10 @@ static val v_gather(match_files_ctx *c)
   val specs = copy_list(second(first_spec));
   val args = third(first_spec);
   val until_last = fourth(first_spec);
-  val vars = vars_to_bindings(specline, getplist(args, vars_k), c->bindings);
+  val have_vars;
+  val vars = vars_to_bindings(specline,
+                              getplist_f(args, vars_k, mkcloc(have_vars)),
+                              c->bindings);
 
   while (specs && c->data) {
     list_collect_decl (new_specs, ptail);
@@ -2669,7 +2672,7 @@ static val v_gather(match_files_ctx *c)
     }
   }
 
-  if (vars) {
+  if (have_vars) {
     val iter;
 
     for (iter = vars; iter != nil; iter = cdr(iter)) {