patch 9.1.0369: Vim9: problem when importing autoloaded scripts

Problem:  Vim9: problem when importing autoloaded scripts
Solution: In `:def` handle storing to vim9 autoload export
          (Ernie Rael)

Problem occurs when `import autoload ./.../autoload/...`. The autoload
in the specified path causes the use of an autoload_prefix which combines
with the `import autoload` to create trouble.

In `generate_store_var()` `case dest_script` use ISN_STOREEXPORT,
when needed, instead of ISN_STORES. When executing ISN_STOREEXPORT,
check for autoload_prefix.

fixes: #14606
closes: #14615

Signed-off-by: Ernie Rael <errael@raelity.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>

src/evalvars.c

@@ -4235,6 +4235,7 @@ failed:
  * - Whether the variable is read-only
  * - Whether the variable value is locked
  * - Whether the variable is locked
+ * NOTE: "name" is only used for error messages.
  */
     int
 var_check_permission(dictitem_T *di, char_u *name)

src/testdir/test_vim9_disassemble.vim

@@ -381,6 +381,34 @@ def Test_disassemble_import_autoload()
   v9.CheckScriptSuccess(lines)
 enddef
 
+def Test_disassemble_import_autoload_autoload()
+  mkdir('Xauto_auto/autoload', 'pR')
+  var lines =<< trim END
+    vim9script
+    export const val = 11
+  END
+  writefile(lines, 'Xauto_auto/autoload/Xauto_vars_f1.vim')
+
+  lines =<< trim END
+    vim9script
+
+    import autoload './Xauto_auto/autoload/Xauto_vars_f1.vim' as f1
+    def F()
+        f1.val = 13
+    enddef
+    var res = execute('disass F')
+
+    assert_match('<SNR>\d*_F.*' ..
+      'f1.val = 13\_s*' ..
+      '\d PUSHNR 13\_s*' ..
+      '\d SOURCE .*/Xauto_auto/autoload/Xauto_vars_f1.vim\_s*' ..
+      '\d STOREEXPORT val in .*/Xauto_auto/autoload/Xauto_vars_f1.vim\_s*' ..
+      '\d RETURN void',
+      res)
+  END
+  v9.CheckScriptSuccess(lines)
+enddef
+
 def s:ScriptFuncStore()
   var localnr = 1
   localnr = 2

src/testdir/test_vim9_func.vim

@@ -166,6 +166,37 @@ def Test_wrong_function_name()
   delfunc g:Define
 enddef
 
+" Check that in a legacy script a :def accesses the correct script variables.
+" Github issue: #14615.
+def Test_access_var_from_legacy_def()
+  # Access a script variable by name WITH "s:" prefix.
+  var lines =<< trim END
+    let s:foo = 'init'
+    let s:xxfoo = 'init'
+    def! AccessVarFromLegacyDef()
+        s:xxfoo = 'CHANGED'
+    enddef
+    call AccessVarFromLegacyDef()
+    call assert_equal('init', s:foo)
+    call assert_equal('CHANGED', s:xxfoo)
+  END
+  v9.CheckScriptSuccess(lines)
+
+  # Access a script variable by name WITHOUT "s:" prefix;
+  # previously this accessed "foo" and not "xxfoo"
+  lines =<< trim END
+    let s:foo = 'init'
+    let s:xxfoo = 'init'
+    def! AccessVarFromLegacyDef()
+        xxfoo = 'CHANGED'
+    enddef
+    call AccessVarFromLegacyDef()
+    call assert_equal('init', s:foo)
+    call assert_equal('CHANGED', s:xxfoo)
+  END
+  v9.CheckScriptSuccess(lines)
+enddef
+
 def Test_listing_function_error()
   var lines =<< trim END
       var filler = 123

src/testdir/test_vim9_import.vim

@@ -1206,6 +1206,7 @@ def Test_autoload_export_variables()
   mkdir('Xautoload_vars/autoload', 'pR')
   var lines =<< trim END
     vim9script
+    g:Xautoload_vars_autoload = true
     export var val = 11
     val = 42
   END
@@ -1215,13 +1216,24 @@ def Test_autoload_export_variables()
   writefile(lines, 'Xautoload_vars/autoload/Xauto_vars_f2.vim', 'D')
   lines =<< trim END
     vim9script
+    g:Xautoload_vars_autoload = false
 
     import autoload './Xautoload_vars/autoload/Xauto_vars_f2.vim' as f2
+    # Verify that the import statement does not load the file.
+    assert_equal(false, g:Xautoload_vars_autoload)
 
     def F(): number
       return f2.val
     enddef
+    # Verify compile does not load the file.
+    defcompile F
+    assert_equal(false, g:Xautoload_vars_autoload)
+
+    # load the file by accessing the exported variable
     assert_equal(42, F())
+    assert_equal(true, g:Xautoload_vars_autoload)
+    unlet g:Xautoload_vars_autoload
+
     assert_equal(42, f2.val)
     f2.val = 17
     assert_equal(17, f2.val)
@@ -1264,6 +1276,44 @@ def Test_autoload_export_variables()
     f4.val = 13
   END
   v9.CheckScriptFailure(lines, 'E46:')
+
+  # Test const var is not modifiable from importing script from :def.
+  # Github issue: #14606
+  lines =<< trim END
+    vim9script
+    export const val = 11
+  END
+  writefile(lines, 'Xautoload_vars/autoload/Xauto_vars_f5.vim', 'D')
+  lines =<< trim END
+    vim9script
+
+    import autoload './Xautoload_vars/autoload/Xauto_vars_f5.vim' as f5
+
+    def F()
+      f5.val = 13
+    enddef
+    F()
+  END
+  v9.CheckScriptFailure(lines, 'E741:')
+
+  # Still part of Github issue: #14606
+  lines =<< trim END
+    vim9script
+    export var val = 11
+  END
+  writefile(lines, 'Xautoload_vars/autoload/Xauto_vars_f6.vim', 'D')
+  lines =<< trim END
+    vim9script
+
+    import autoload './Xautoload_vars/autoload/Xauto_vars_f6.vim' as f6
+
+    def F()
+      f6.val = 13
+    enddef
+    F()
+    assert_equal(13, f6.val)
+  END
+  v9.CheckScriptSuccess(lines)
 enddef
 
 def Test_autoload_import_relative_autoload_dir()

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    369,
 /**/
     368,
 /**/

src/vim9.h

@@ -780,6 +780,7 @@ typedef enum {
     dest_vimvar,
     dest_class_member,
     dest_script,
+    dest_script_v9,
     dest_reg,
     dest_expr,
 } assign_dest_T;

src/vim9compile.c

@@ -1367,6 +1367,7 @@ generate_loadvar(cctx_T *cctx, lhs_T *lhs)
 	    generate_LOAD(cctx, ISN_LOADT, 0, name + 2, type);
 	    break;
 	case dest_script:
+	case dest_script_v9:
 	    res = compile_load_scriptvar(cctx,
 				  name + (name[1] == ':' ? 2 : 0), NULL, NULL);
 	    break;
@@ -1838,7 +1839,8 @@ compile_lhs(
 			return FAIL;
 		    }
 
-		    lhs->lhs_dest = dest_script;
+		    lhs->lhs_dest = current_script_is_vim9()
+			      ? dest_script_v9 : dest_script;
 
 		    // existing script-local variables should have a type
 		    lhs->lhs_scriptvar_sid = current_sctx.sc_sid;
@@ -3026,6 +3028,7 @@ compile_assignment(
 	else
 	{
 	    if (is_decl && cmdidx == CMD_const && (lhs.lhs_dest == dest_script
+					    || lhs.lhs_dest == dest_script_v9
 					    || lhs.lhs_dest == dest_global
 					    || lhs.lhs_dest == dest_local))
 		// ":const var": lock the value, but not referenced variables

src/vim9execute.c

@@ -3842,11 +3842,19 @@ exec_instructions(ectx_T *ectx)
 	    case ISN_STOREEXPORT:
 		{
 		    int		sid = iptr->isn_arg.loadstore.ls_sid;
-		    hashtab_T	*ht = &SCRIPT_VARS(sid);
 		    char_u	*name = iptr->isn_arg.loadstore.ls_name;
-		    dictitem_T	*di = find_var_in_ht(ht, 0,
+		    dictitem_T	*di = NULL;
-					    iptr->isn_type == ISN_STORES
+		    // First check for a variable from an exported autoload
+		    // with an autoload_prefix; it would be in globals.
+		    if (iptr->isn_type == ISN_STOREEXPORT)
+			di = find_var_autoload_prefix(name, sid, NULL, NULL);
+		    // Then look for a variable in the script's variables.
+		    if (di == NULL)
+		    {
+			hashtab_T	*ht = &SCRIPT_VARS(sid);
+			di = find_var_in_ht(ht, 0, STRNCMP("s:", name, 2) == 0
 						     ? name + 2 : name, TRUE);
+		    }
 
 		    --ectx->ec_stack.ga_len;
 		    SOURCING_LNUM = iptr->isn_lnum;

src/vim9instr.c

@@ -2394,6 +2394,7 @@ generate_store_var(
 	case dest_vimvar:
 	    return generate_STORE(cctx, ISN_STOREV, vimvaridx, NULL);
 	case dest_script:
+	case dest_script_v9:
 	    {
 		int	    scriptvar_idx = lhs->lhs_scriptvar_idx;
 		int	    scriptvar_sid = lhs->lhs_scriptvar_sid;
@@ -2401,10 +2402,14 @@ generate_store_var(
 		{
 		    isntype_T   isn_type = ISN_STORES;
 
+		    // If "sn_import_autoload", generate ISN_STOREEXPORT (not
+		    // ISN_STORES) if destination is in a vim9script or if
+		    // there is no "sn_autoload_prefix".
 		    if (SCRIPT_ID_VALID(scriptvar_sid)
 			     && SCRIPT_ITEM(scriptvar_sid)->sn_import_autoload
-			     && SCRIPT_ITEM(scriptvar_sid)->sn_autoload_prefix
+			     && ((SCRIPT_ITEM(scriptvar_sid)
-								       == NULL)
+						  ->sn_autoload_prefix == NULL)
+				|| lhs->lhs_dest == dest_script_v9))
 		    {
 			// "import autoload './dir/script.vim'" - load script
 			// first