vim-patch:8.2.3216: Vim9: crash when using variable in a loop at script level

Problem:    Vim9: crash when using variable in a loop at script level.
Solution:   Do not clear the variable if a function was defined.
            Do not create a new entry in sn_var_vals every time.
            (closes vim/vim#8628)

https://github.com/vim/vim/commit/2eb6fc3b52148f961e804ec2be361d531ff770d8

Omit eval_cstack: Vim9 script only.

Co-authored-by: Bram Moolenaar <Bram@vim.org>

3 files changed, 11 insertions, 23 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index a088e6d253..ad2d854e1e 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -695,9 +695,11 @@ void eval_patch(const char *const origfile, const char *const difffile, const ch
 void fill_evalarg_from_eap(evalarg_T *evalarg, exarg_T *eap, bool skip)
 {
   *evalarg = (evalarg_T){ .eval_flags = skip ? 0 : EVAL_EVALUATE };
-  if (eap != NULL && getline_equal(eap->getline, eap->cookie, getsourceline)) {
-    evalarg->eval_getline = eap->getline;
-    evalarg->eval_cookie = eap->cookie;
+  if (eap != NULL) {
+    if (getline_equal(eap->getline, eap->cookie, getsourceline)) {
+      evalarg->eval_getline = eap->getline;
+      evalarg->eval_cookie = eap->cookie;
+    }
   }
 }
 
diff --git a/src/nvim/eval/vars.c b/src/nvim/eval/vars.c
index 4bce555d75..c4a9823c0a 100644
--- a/src/nvim/eval/vars.c
+++ b/src/nvim/eval/vars.c
@@ -259,13 +259,8 @@ void ex_let(exarg_T *eap)
   if (eap->skip) {
     emsg_skip++;
   }
-  evalarg_T evalarg = {
-    .eval_flags = eap->skip ? 0 : EVAL_EVALUATE,
-  };
-  if (getline_equal(eap->getline, eap->cookie, getsourceline)) {
-    evalarg.eval_getline = eap->getline;
-    evalarg.eval_cookie = eap->cookie;
-  }
+  evalarg_T evalarg;
+  fill_evalarg_from_eap(&evalarg, eap, eap->skip);
   int eval_res = eval0(expr, &rettv, eap, &evalarg);
   if (eap->skip) {
     emsg_skip--;
diff --git a/src/nvim/ex_eval.c b/src/nvim/ex_eval.c
index 63ead3550f..5404ae6731 100644
--- a/src/nvim/ex_eval.c
+++ b/src/nvim/ex_eval.c
@@ -957,21 +957,12 @@ void ex_while(exarg_T *eap)
       eap->cmdidx == CMD_while ? CSF_WHILE : CSF_FOR;
 
     int skip = CHECK_SKIP;
-    if (eap->cmdidx == CMD_while) {
-      // ":while bool-expr"
+    if (eap->cmdidx == CMD_while) {  // ":while bool-expr"
       result = eval_to_bool(eap->arg, &error, eap, skip);
-    } else {
+    } else {  // ":for var in list-expr"
+      evalarg_T evalarg;
+      fill_evalarg_from_eap(&evalarg, eap, skip);
       void *fi;
-
-      evalarg_T evalarg = {
-        .eval_flags = eap->skip ? 0 : EVAL_EVALUATE,
-      };
-      if (getline_equal(eap->getline, eap->cookie, getsourceline)) {
-        evalarg.eval_getline = eap->getline;
-        evalarg.eval_cookie = eap->cookie;
-      }
-
-      // ":for var in list-expr"
       if ((cstack->cs_lflags & CSL_HAD_LOOP) != 0) {
         // Jumping here from a ":continue" or ":endfor": use the
         // previously evaluated list.