vim-patch:9.1.1071: args missing after failing to redefine a function

Problem:  Arguments of a function are missing after failing to redefine
          it (after 8.2.2505), and heap-use-after-free with script-local
          function (after 9.1.1063).
Solution: Don't clear arguments or free uf_name_exp when failing to
          redefine an existing function (zeertzjq)

closes: vim/vim#16567

https://github.com/vim/vim/commit/04d2a3fdc051d6a419dc0ea4de7a9640cefccd31

1 files changed, 6 insertions, 5 deletions

diff --git a/src/nvim/eval/userfunc.c b/src/nvim/eval/userfunc.c
index 402798cafa..8022b37f6b 100644
--- a/src/nvim/eval/userfunc.c
+++ b/src/nvim/eval/userfunc.c
@@ -2825,11 +2825,11 @@ void ex_function(exarg_T *eap)
           && (fp->uf_script_ctx.sc_sid != current_sctx.sc_sid
               || fp->uf_script_ctx.sc_seq == current_sctx.sc_seq)) {
         emsg_funcname(e_funcexts, name);
-        goto erret;
+        goto errret_keep;
       }
       if (fp->uf_calls > 0) {
         emsg_funcname(N_("E127: Cannot redefine function %s: It is in use"), name);
-        goto erret;
+        goto errret_keep;
       }
       if (fp->uf_refcount > 1) {
         // This function is referenced somewhere, don't redefine it but
@@ -2961,9 +2961,6 @@ erret:
     ga_init(&fp->uf_def_args, (int)sizeof(char *), 1);
   }
 errret_2:
-  ga_clear_strings(&newargs);
-  ga_clear_strings(&default_args);
-  ga_clear_strings(&newlines);
   if (fp != NULL) {
     XFREE_CLEAR(fp->uf_name_exp);
   }
@@ -2971,6 +2968,10 @@ errret_2:
     xfree(fp);
     fp = NULL;
   }
+errret_keep:
+  ga_clear_strings(&newargs);
+  ga_clear_strings(&default_args);
+  ga_clear_strings(&newlines);
 ret_free:
   xfree(line_to_free);
   xfree(fudi.fd_newkey);