patch 9.1.1828: local variables shadowed by import names

Problem:  local variables shadowed by import names
Solution: Check if a local variable exists before handling imports
          (thinca)

closes: #18480

Signed-off-by: thinca <[email protected]>
Signed-off-by: Christian Brabandt <[email protected]>

Author: thinca

src/eval.c

@@ -2236,13 +2236,33 @@ get_lval(
 
     if (*p == '.')
     {
-	imported_T *import = find_imported(lp->ll_name, p - lp->ll_name, TRUE);
-	if (import != NULL)
+	// In legacy script, when a local variable and import exists with this name,
+	// prioritize local variable over imports to avoid conflicts.
+	int var_exists = FALSE;
+	if (!vim9script)
+	{
+	    cc = *p;
+	    *p = NUL;
+	    hashtab_T *local_ht = get_funccal_local_ht();
+	    if (local_ht != NULL)
+	    {
+		hashitem_T *hi = hash_find(local_ht, lp->ll_name);
+		if (!HASHITEM_EMPTY(hi))
+		    var_exists = TRUE;
+	    }
+	    *p = cc;
+	}
+
+	if (!var_exists)
 	{
-	    p++;	// skip '.'
-	    p = get_lval_imported(lp, import->imp_sid, p, &v, fne_flags);
-	    if (p == NULL)
-		return NULL;
+	    imported_T *import = find_imported(lp->ll_name, p - lp->ll_name, TRUE);
+	    if (import != NULL)
+	    {
+		p++;	// skip '.'
+		p = get_lval_imported(lp, import->imp_sid, p, &v, fne_flags);
+		if (p == NULL)
+		    return NULL;
+	    }
 	}
     }
 

src/testdir/test_vim9_import.vim

@@ -3694,4 +3694,29 @@ def Test_import_member_initializer()
   v9.CheckScriptSuccess(lines)
 enddef
 
+def Test_import_name_conflict_with_local_variable()
+  var lines =<< trim END
+    vim9script
+
+    export class Foo
+      def Method(): string
+        return 'Method'
+      enddef
+    endclass
+  END
+  writefile(lines, 'Xvim9.vim', 'D')
+
+  lines =<< trim END
+    import './Xvim9.vim'
+
+    function! s:Main() abort
+      let Xvim9 = s:Xvim9.Foo.new()
+      call assert_equal('Method', Xvim9.Method())
+    endfunction
+
+    call s:Main()
+  END
+  v9.CheckScriptSuccess(lines)
+enddef
+
 " vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker

src/version.c

@@ -729,6 +729,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1828,
 /**/
     1827,
 /**/