vim-patch:8.2.1067: expression "!expr->func()" does not work (#22585)

Problem:    Expression "!expr->func()" does not work.
Solution:   Apply plus and minus earlier. (closes vim/vim#6348)

0b1cd52ff6

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

src/nvim/eval.c

@@ -2906,6 +2906,12 @@ static int eval7(char **arg, typval_T *rettv, int evaluate, int want_string)
   case '8':
   case '9':
     ret = get_number_tv(arg, rettv, evaluate, want_string);
+
+    // Apply prefixed "-" and "+" now.  Matters especially when
+    // "->" follows.
+    if (ret == OK && evaluate && end_leader > start_leader) {
+      ret = eval7_leader(rettv, true, start_leader, &end_leader);
+    }
     break;
 
   // String constant: "string".
@@ -3011,13 +3017,12 @@ static int eval7(char **arg, typval_T *rettv, int evaluate, int want_string)
   // Handle following '[', '(' and '.' for expr[expr], expr.name,
   // expr(expr), expr->name(expr)
   if (ret == OK) {
-    ret = handle_subscript((const char **)arg, rettv, evaluate, true,
-                           (char *)start_leader, &end_leader);
+    ret = handle_subscript((const char **)arg, rettv, evaluate, true);
   }
 
   // Apply logical NOT and unary '-', from right to left, ignore '+'.
   if (ret == OK && evaluate && end_leader > start_leader) {
-    ret = eval7_leader(rettv, (char *)start_leader, &end_leader);
+    ret = eval7_leader(rettv, false, start_leader, &end_leader);
   }
 
   recurse--;
@@ -3027,9 +3032,11 @@ static int eval7(char **arg, typval_T *rettv, int evaluate, int want_string)
 /// Apply the leading "!" and "-" before an eval7 expression to "rettv".
 /// Adjusts "end_leaderp" until it is at "start_leader".
 ///
+/// @param numeric_only  if true only handle "+" and "-".
+///
 /// @return  OK on success, FAIL on failure.
-static int eval7_leader(typval_T *const rettv, const char *const start_leader,
-                        const char **const end_leaderp)
+static int eval7_leader(typval_T *const rettv, const bool numeric_only,
+                        const char *const start_leader, const char **const end_leaderp)
   FUNC_ATTR_NONNULL_ALL
 {
   const char *end_leader = (char *)(*end_leaderp);
@@ -3050,6 +3057,10 @@ static int eval7_leader(typval_T *const rettv, const char *const start_leader,
     while (end_leader > start_leader) {
       end_leader--;
       if (*end_leader == '!') {
+        if (numeric_only) {
+          end_leader++;
+          break;
+        }
         if (rettv->v_type == VAR_FLOAT) {
           f = !(bool)f;
         } else {
@@ -6899,8 +6910,7 @@ int check_luafunc_name(const char *const str, const bool paren)
 /// @param verbose  give error messages
 /// @param start_leader  start of '!' and '-' prefixes
 /// @param end_leaderp  end of '!' and '-' prefixes
-int handle_subscript(const char **const arg, typval_T *rettv, int evaluate, int verbose,
-                     const char *const start_leader, const char **const end_leaderp)
+int handle_subscript(const char **const arg, typval_T *rettv, int evaluate, int verbose)
 {
   int ret = OK;
   dict_T *selfdict = NULL;
@@ -6944,11 +6954,6 @@ int handle_subscript(const char **const arg, typval_T *rettv, int evaluate, int
       tv_dict_unref(selfdict);
       selfdict = NULL;
     } else if (**arg == '-') {
-      // Expression "-1.0->method()" applies the leader "-" before
-      // applying ->.
-      if (evaluate && *end_leaderp > start_leader) {
-        ret = eval7_leader(rettv, (char *)start_leader, end_leaderp);
-      }
       if (ret == OK) {
         if ((*arg)[2] == '{') {
           // expr->{lambda}()

src/nvim/eval/userfunc.c

@@ -3075,8 +3075,7 @@ void ex_call(exarg_T *eap)
     }
 
     // Handle a function returning a Funcref, Dictionary or List.
-    if (handle_subscript((const char **)&arg, &rettv, true, true,
-                         (const char *)name, (const char **)&name)
+    if (handle_subscript((const char **)&arg, &rettv, true, true)
         == FAIL) {
       failed = true;
       break;

src/nvim/eval/vars.c

@@ -508,7 +508,7 @@ static const char *list_arg_vars(exarg_T *eap, const char *arg, int *first)
         } else {
           // handle d.key, l[idx], f(expr)
           const char *const arg_subsc = arg;
-          if (handle_subscript(&arg, &tv, true, true, name, &name) == FAIL) {
+          if (handle_subscript(&arg, &tv, true, true) == FAIL) {
             error = true;
           } else {
             if (arg == arg_subsc && len == 2 && name[1] == ':') {
@@ -1715,7 +1715,7 @@ bool var_exists(const char *var)
     n = get_var_tv(name, len, &tv, NULL, false, true) == OK;
     if (n) {
       // Handle d.key, l[idx], f(expr).
-      n = handle_subscript(&var, &tv, true, false, name, &name) == OK;
+      n = handle_subscript(&var, &tv, true, false) == OK;
       if (n) {
         tv_clear(&tv);
       }

test/old/testdir/test_expr.vim

@@ -111,6 +111,13 @@ func Test_special_char()
   call assert_fails('echo "\<C-">')
 endfunc
 
+func Test_method_with_prefix()
+  call assert_equal(1, !range(5)->empty())
+  call assert_equal([0, 1, 2], --3->range())
+  call assert_equal(0, !-3)
+  call assert_equal(1, !+-+0)
+endfunc
+
 func Test_option_value()
   " boolean
   set bri