vim-patch:8.2.2664: Vim9: not enough function arguments checked for string

Problem:    Vim9: not enough function arguments checked for string.
Solution:   Check in balloon functions.  Refactor function arguments.
https://github.com/vim/vim/commit/32105ae88f3aa6a6af30336f0bc9f8eb81292cd7

Cherry-pick removal of useless check from patch 8.2.3840.

vim-patch:8.2.3083: crash when passing null string to charclass()

Problem:    Crash when passing null string to charclass().
Solution:   Bail out when string pointer is NULL. (Christian Brabandt,
            closes vim/vim#8498, closes vim/vim#8260)
https://github.com/vim/vim/commit/72463f883cdfd08e29ab0018ef3889284848d5f1

3 files changed, 12 insertions, 20 deletions

diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index 99dfa13d88..bff4361dcb 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -1772,7 +1772,7 @@ static void f_eventhandler(typval_T *argvars, typval_T *rettv, EvalFuncData fptr
 /// "executable()" function
 static void f_executable(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  if (tv_check_for_string(&argvars[0], 1) == FAIL) {
+  if (tv_check_for_string_arg(argvars, 0) == FAIL) {
     return;
   }
 
@@ -1901,7 +1901,7 @@ static void f_win_execute(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 /// "exepath()" function
 static void f_exepath(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  if (tv_check_for_nonempty_string(&argvars[0], 1) == FAIL) {
+  if (tv_check_for_nonempty_string_arg(argvars, 0) == FAIL) {
     return;
   }
 
diff --git a/src/nvim/eval/typval.c b/src/nvim/eval/typval.c
index 3bc3cdbd6b..c75d16e4fc 100644
--- a/src/nvim/eval/typval.c
+++ b/src/nvim/eval/typval.c
@@ -3805,34 +3805,26 @@ float_T tv_get_float(const typval_T *const tv)
   return 0;
 }
 
-/// Give an error and return FAIL unless "tv" is a string.
-int tv_check_for_string(const typval_T *const tv, const int arg)
+/// Give an error and return FAIL unless "args[idx]" is a string.
+int tv_check_for_string_arg(const typval_T *const args, const int idx)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
 {
-  if (tv->v_type != VAR_STRING) {
-    if (arg > 0) {
-      semsg(_(e_string_required_for_argument_nr), arg);
-    } else {
-      emsg(_(e_stringreq));
-    }
+  if (args[idx].v_type != VAR_STRING) {
+    semsg(_(e_string_required_for_argument_nr), idx + 1);
     return FAIL;
   }
   return OK;
 }
 
-/// Give an error and return FAIL unless "tv" is a non-empty string.
-int tv_check_for_nonempty_string(const typval_T *const tv, const int arg)
+/// Give an error and return FAIL unless "args[idx]" is a non-empty string.
+int tv_check_for_nonempty_string_arg(const typval_T *const args, const int idx)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
 {
-  if (tv_check_for_string(tv, arg) == FAIL) {
+  if (tv_check_for_string_arg(args, idx) == FAIL) {
     return FAIL;
   }
-  if (tv->vval.v_string == NULL || *tv->vval.v_string == NUL) {
-    if (arg > 0) {
-      semsg(_(e_non_empty_string_required_for_argument_nr), arg);
-    } else {
-      emsg(_(e_non_empty_string_required));
-    }
+  if (args[idx].vval.v_string == NULL || *args[idx].vval.v_string == NUL) {
+    semsg(_(e_non_empty_string_required_for_argument_nr), idx + 1);
     return FAIL;
   }
   return OK;
diff --git a/src/nvim/mbyte.c b/src/nvim/mbyte.c
index ebb5e2317b..310ad05196 100644
--- a/src/nvim/mbyte.c
+++ b/src/nvim/mbyte.c
@@ -2793,7 +2793,7 @@ void f_setcellwidths(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 
 void f_charclass(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
-  if (tv_check_for_string(&argvars[0], 1) == FAIL
+  if (tv_check_for_string_arg(argvars, 0) == FAIL
       || argvars[0].vval.v_string == NULL) {
     return;
   }