patch 8.2.2343: Vim9: return type of readfile() is any

Problem:    Vim9: return type of readfile() is any.
Solution:   Add readblob() so that readfile() can be expected to always
            return a list of strings. (closes #7671)

src/evalfunc.c

@@ -1344,12 +1344,14 @@ static funcentry_T global_functions[] =
 			ret_number,	    f_rand},
     {"range",		1, 3, FEARG_1,	    NULL,
 			ret_list_number,    f_range},
+    {"readblob",	1, 1, FEARG_1,	    NULL,
+			ret_blob,	    f_readblob},
     {"readdir",		1, 3, FEARG_1,	    NULL,
 			ret_list_string,    f_readdir},
     {"readdirex",	1, 3, FEARG_1,	    NULL,
 			ret_list_dict_any,  f_readdirex},
     {"readfile",	1, 3, FEARG_1,	    NULL,
-			ret_any,	    f_readfile},
+			ret_list_string,    f_readfile},
     {"reduce",		2, 3, FEARG_1,	    NULL,
 			ret_any,	    f_reduce},
     {"reg_executing",	0, 0, 0,	    NULL,

src/filepath.c

@@ -1640,11 +1640,11 @@ f_readdirex(typval_T *argvars, typval_T *rettv)
 /*
  * "readfile()" function
  */
-    void
-f_readfile(typval_T *argvars, typval_T *rettv)
+    static void
+read_file_or_blob(typval_T *argvars, typval_T *rettv, int always_blob)
 {
     int		binary = FALSE;
-    int		blob = FALSE;
+    int		blob = always_blob;
     int		failed = FALSE;
     char_u	*fname;
     FILE	*fd;
@@ -1796,7 +1796,8 @@ f_readfile(typval_T *argvars, typval_T *rettv)
 
 			if (dest < buf)
 			{
-			    adjust_prevlen = (int)(buf - dest); // must be 1 or 2
+			    // must be 1 or 2
+			    adjust_prevlen = (int)(buf - dest);
 			    dest = buf;
 			}
 			if (readlen > p - buf + 1)
@@ -1866,6 +1867,24 @@ f_readfile(typval_T *argvars, typval_T *rettv)
     fclose(fd);
 }
 
+/*
+ * "readblob()" function
+ */
+    void
+f_readblob(typval_T *argvars, typval_T *rettv)
+{
+    read_file_or_blob(argvars, rettv, TRUE);
+}
+
+/*
+ * "readfile()" function
+ */
+    void
+f_readfile(typval_T *argvars, typval_T *rettv)
+{
+    read_file_or_blob(argvars, rettv, FALSE);
+}
+
 /*
  * "resolve()" function
  */

src/proto/filepath.pro

@@ -1,5 +1,6 @@
 /* filepath.c */
 int modify_fname(char_u *src, int tilde_file, int *usedlen, char_u **fnamep, char_u **bufp, int *fnamelen);
+void shorten_dir(char_u *str);
 void f_chdir(typval_T *argvars, typval_T *rettv);
 void f_delete(typval_T *argvars, typval_T *rettv);
 void f_executable(typval_T *argvars, typval_T *rettv);
@@ -21,10 +22,10 @@ void f_glob2regpat(typval_T *argvars, typval_T *rettv);
 void f_globpath(typval_T *argvars, typval_T *rettv);
 void f_isdirectory(typval_T *argvars, typval_T *rettv);
 void f_mkdir(typval_T *argvars, typval_T *rettv);
-void shorten_dir(char_u *str);
 void f_pathshorten(typval_T *argvars, typval_T *rettv);
 void f_readdir(typval_T *argvars, typval_T *rettv);
 void f_readdirex(typval_T *argvars, typval_T *rettv);
+void f_readblob(typval_T *argvars, typval_T *rettv);
 void f_readfile(typval_T *argvars, typval_T *rettv);
 void f_resolve(typval_T *argvars, typval_T *rettv);
 void f_tempname(typval_T *argvars, typval_T *rettv);

src/testdir/test_vim9_builtin.vim

@@ -623,6 +623,32 @@ def Test_readdir()
    eval expand('sautest')->readdirex((e) => e.name[0] !=# '.')
 enddef
 
+def Test_readblob()
+  var blob = 0z12341234
+  writefile(blob, 'Xreadblob')
+  var read: blob = readblob('Xreadblob')
+  assert_equal(blob, read)
+
+  var lines =<< trim END
+      var read: list<string> = readblob('Xreadblob')
+  END
+  CheckDefAndScriptFailure(lines, 'E1012: Type mismatch; expected list<string> but got blob', 1)
+  delete('Xreadblob')
+enddef
+
+def Test_readfile()
+  var text = ['aaa', 'bbb', 'ccc']
+  writefile(text, 'Xreadfile')
+  var read: list<string> = readfile('Xreadfile')
+  assert_equal(text, read)
+
+  var lines =<< trim END
+      var read: dict<string> = readfile('Xreadfile')
+  END
+  CheckDefAndScriptFailure(lines, 'E1012: Type mismatch; expected dict<string> but got list<string>', 1)
+  delete('Xreadfile')
+enddef
+
 def Test_remove_return_type()
   var l = remove({one: [1, 2], two: [3, 4]}, 'one')
   var res = 0

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2343,
 /**/
     2342,
 /**/