PATCH: fix autoload +X nonexist leaving funcdef at dummy

% autoload +X nonexist
zsh:999: nonexist: function definition file not found
% nonexist
 exec.c:6086: function definition nonexist has zero reference count

All the paths that set shf->funcdef in loadautofn call freeeprog on
the old one first anyway, so rather than make a new mkautofn if
loadautofn fails, just keep the old one.
---
 Src/builtin.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Src/builtin.c b/Src/builtin.c
index 96bfd64cb5..d7ee2d0756 100644
--- a/Src/builtin.c
+++ b/Src/builtin.c
@@ -3168,11 +3168,11 @@ eval_autoload(Shfunc shf, char *name, Options ops, int func)
     if (!(shf->node.flags & PM_UNDEFINED))
 	return 1;
 
-    if (shf->funcdef) {
-	freeeprog(shf->funcdef);
-	shf->funcdef = &dummy_eprog;
-    }
     if (OPT_MINUS(ops,'X')) {
+	if (shf->funcdef) {
+	    freeeprog(shf->funcdef);
+	    shf->funcdef = &dummy_eprog;
+	}
 	char *fargv[3];
 	fargv[0] = quotestring(name, QT_SINGLE_OPTIONAL);
 	fargv[1] = "\"$@\"";
-- 
2.38.1