patch 8.2.3904: Vim9: skip expression type is not checked at compile time

Problem:    Vim9: skip expression type is not checked at compile time.
Solution:   Add argument type checks.

src/evalfunc.c

@@ -532,6 +532,26 @@ arg_map_func(type_T *type, argcontext_T *context)
     return OK;
 }
 
+/*
+ * Check an expression argument, can be a string, funcref or partial.
+ * Also accept a bool, a constant resulting from compiling a string argument.
+ * Also accept a number, one and zero are accepted.
+ */
+    static int
+arg_string_or_func(type_T *type, argcontext_T *context)
+{
+    if (type->tt_type == VAR_ANY
+	    || type->tt_type == VAR_UNKNOWN
+	    || type->tt_type == VAR_STRING
+	    || type->tt_type == VAR_PARTIAL
+	    || type->tt_type == VAR_FUNC
+	    || type->tt_type == VAR_BOOL
+	    || type->tt_type == VAR_NUMBER)
+	return OK;
+    arg_type_mismatch(&t_func_any, type, context->arg_idx + 1);
+    return FAIL;
+}
+
 /*
  * Check "type" is a list of 'any' or a blob or a string.
  */
@@ -916,8 +936,8 @@ static argcheck_T arg23_reduce[] = {arg_string_list_or_blob, NULL, NULL};
 static argcheck_T arg24_remote_expr[] = {arg_string, arg_string, arg_string, arg_number};
 static argcheck_T arg23_remove[] = {arg_list_or_dict_or_blob, arg_remove2, arg_number};
 static argcheck_T arg2_repeat[] = {arg_repeat1, arg_number};
-static argcheck_T arg15_search[] = {arg_string, arg_string, arg_number, arg_number, NULL};
+static argcheck_T arg15_search[] = {arg_string, arg_string, arg_number, arg_number, arg_string_or_func};
-static argcheck_T arg37_searchpair[] = {arg_string, arg_string, arg_string, arg_string, NULL, arg_number, arg_number};
+static argcheck_T arg37_searchpair[] = {arg_string, arg_string, arg_string, arg_string, arg_string_or_func, arg_number, arg_number};
 static argcheck_T arg3_setbufline[] = {arg_buffer, arg_lnum, arg_str_or_nr_or_list};
 static argcheck_T arg2_setline[] = {arg_lnum, NULL};
 static argcheck_T arg24_setloclist[] = {arg_number, arg_list_any, arg_string, arg_dict_any};

src/testdir/test_vim9_builtin.vim

@@ -3007,6 +3007,10 @@ def Test_search()
   CheckDefAndScriptFailure(['search("a", 2)'], ['E1013: Argument 2: type mismatch, expected string but got number', 'E1174: String required for argument 2'])
   CheckDefAndScriptFailure(['search("a", "b", "c")'], ['E1013: Argument 3: type mismatch, expected number but got string', 'E1210: Number required for argument 3'])
   CheckDefAndScriptFailure(['search("a", "b", 3, "d")'], ['E1013: Argument 4: type mismatch, expected number but got string', 'E1210: Number required for argument 4'])
+  new
+  setline(1, "match this")
+  CheckDefAndScriptFailure(['search("a", "", 9, 0, [0])'], ['E1013: Argument 5: type mismatch, expected func(...): any but got list<number>', 'E730: Using a List as a String'])
+  bwipe!
 enddef
 
 def Test_searchcount()
@@ -3058,9 +3062,12 @@ def Test_searchpair()
       vim9script
       setline(1, '()')
       normal gg
+      func RetList()
+        return [0]
+      endfunc
       def Fail()
         try
-          searchpairpos('(', '', ')', 'nW', '[0]->map("")')
+          searchpairpos('(', '', ')', 'nW', 'RetList()')
         catch
           g:caught = 'yes'
         endtry
@@ -3077,12 +3084,35 @@ def Test_searchpair()
   END
   CheckDefAndScriptFailure(lines, ['E1001: Variable not found: f', 'E475: Invalid argument: d'])
 
-  CheckDefAndScriptFailure(['searchpair(1, "b", "c")'], ['E1013: Argument 1: type mismatch, expected string but got number', 'E1174: String required for argument 1'])
+  var errors = ['E1013: Argument 1: type mismatch, expected string but got number', 'E1174: String required for argument 1']
-  CheckDefAndScriptFailure(['searchpair("a", 2, "c")'], ['E1013: Argument 2: type mismatch, expected string but got number', 'E1174: String required for argument 2'])
+  CheckDefAndScriptFailure(['searchpair(1, "b", "c")'], errors)
-  CheckDefAndScriptFailure(['searchpair("a", "b", 3)'], ['E1013: Argument 3: type mismatch, expected string but got number', 'E1174: String required for argument 3'])
+  CheckDefAndScriptFailure(['searchpairpos(1, "b", "c")'], errors)
-  CheckDefAndScriptFailure(['searchpair("a", "b", "c", 4)'], ['E1013: Argument 4: type mismatch, expected string but got number', 'E1174: String required for argument 4'])
+
-  CheckDefAndScriptFailure(['searchpair("a", "b", "c", "r", "1", "f")'], ['E1013: Argument 6: type mismatch, expected number but got string', 'E1210: Number required for argument 6'])
+  errors = ['E1013: Argument 2: type mismatch, expected string but got number', 'E1174: String required for argument 2']
-  CheckDefAndScriptFailure(['searchpair("a", "b", "c", "r", "1", 3, "g")'], ['E1013: Argument 7: type mismatch, expected number but got string', 'E1210: Number required for argument 7'])
+  CheckDefAndScriptFailure(['searchpair("a", 2, "c")'], errors)
+  CheckDefAndScriptFailure(['searchpairpos("a", 2, "c")'], errors)
+
+  errors = ['E1013: Argument 3: type mismatch, expected string but got number', 'E1174: String required for argument 3']
+  CheckDefAndScriptFailure(['searchpair("a", "b", 3)'], errors)
+  CheckDefAndScriptFailure(['searchpairpos("a", "b", 3)'], errors)
+
+  errors = ['E1013: Argument 4: type mismatch, expected string but got number', 'E1174: String required for argument 4']
+  CheckDefAndScriptFailure(['searchpair("a", "b", "c", 4)'], errors)
+
+  new
+  setline(1, "match this")
+  errors = ['E1013: Argument 5: type mismatch, expected func(...): any but got list<number>', 'E730: Using a List as a String']
+  CheckDefAndScriptFailure(['searchpair("a", "b", "c", "r", [0])'], errors)
+  CheckDefAndScriptFailure(['searchpairpos("a", "b", "c", "r", [0])'], errors)
+  bwipe!
+
+  errors = ['E1013: Argument 6: type mismatch, expected number but got string', 'E1210: Number required for argument 6']
+  CheckDefAndScriptFailure(['searchpair("a", "b", "c", "r", "1", "f")'], errors)
+  CheckDefAndScriptFailure(['searchpairpos("a", "b", "c", "r", "1", "f")'], errors)
+
+  errors = ['E1013: Argument 7: type mismatch, expected number but got string', 'E1210: Number required for argument 7']
+  CheckDefAndScriptFailure(['searchpair("a", "b", "c", "r", "1", 3, "g")'], errors)
+  CheckDefAndScriptFailure(['searchpairpos("a", "b", "c", "r", "1", 3, "g")'], errors)
 enddef
 
 def Test_searchpos()
@@ -3090,6 +3120,10 @@ def Test_searchpos()
   CheckDefAndScriptFailure(['searchpos("a", 2)'], ['E1013: Argument 2: type mismatch, expected string but got number', 'E1174: String required for argument 2'])
   CheckDefAndScriptFailure(['searchpos("a", "b", "c")'], ['E1013: Argument 3: type mismatch, expected number but got string', 'E1210: Number required for argument 3'])
   CheckDefAndScriptFailure(['searchpos("a", "b", 3, "d")'], ['E1013: Argument 4: type mismatch, expected number but got string', 'E1210: Number required for argument 4'])
+  new
+  setline(1, "match this")
+  CheckDefAndScriptFailure(['searchpos("a", "", 9, 0, [0])'], ['E1013: Argument 5: type mismatch, expected func(...): any but got list<number>', 'E730: Using a List as a String'])
+  bwipe!
 enddef
 
 def Test_server2client()

src/version.c

@@ -749,6 +749,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3904,
 /**/
     3903,
 /**/