From 7e25fb4a430cb8152d9c67899512152a8fcc2640 Mon Sep 17 00:00:00 2001
From: techatrix <19954306+Techatrix@users.noreply.github.com>
Date: Fri, 28 Jul 2023 00:18:29 +0200
Subject: [PATCH] add bound check on for and while nodes

---
 lib/std/zig/Ast.zig         | 18 +++++++++---------
 lib/std/zig/parser_test.zig | 11 +++++++++++
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/lib/std/zig/Ast.zig b/lib/std/zig/Ast.zig
index a82982e262..7987d19778 100644
--- a/lib/std/zig/Ast.zig
+++ b/lib/std/zig/Ast.zig
@@ -752,11 +752,11 @@ pub fn firstToken(tree: Ast, node: Node.Index) TokenIndex {
             // Look for a label and inline.
             const main_token = main_tokens[n];
             var result = main_token;
-            if (token_tags[result - 1] == .keyword_inline) {
+            if (token_tags[result -| 1] == .keyword_inline) {
                 result -= 1;
             }
-            if (token_tags[result - 1] == .colon) {
-                result -= 2;
+            if (token_tags[result -| 1] == .colon) {
+                result -|= 2;
             }
             return result - end_offset;
         },
@@ -2246,13 +2246,13 @@ fn fullWhileComponents(tree: Ast, info: full.While.Components) full.While {
         .else_token = undefined,
         .error_token = null,
     };
-    var tok_i = info.while_token - 1;
+    var tok_i = info.while_token -| 1;
     if (token_tags[tok_i] == .keyword_inline) {
         result.inline_token = tok_i;
-        tok_i -= 1;
+        tok_i -|= 1;
     }
     if (token_tags[tok_i] == .colon and
-        token_tags[tok_i - 1] == .identifier)
+        token_tags[tok_i -| 1] == .identifier)
     {
         result.label_token = tok_i - 1;
     }
@@ -2280,13 +2280,13 @@ fn fullForComponents(tree: Ast, info: full.For.Components) full.For {
         .payload_token = undefined,
         .else_token = undefined,
     };
-    var tok_i = info.for_token - 1;
+    var tok_i = info.for_token -| 1;
     if (token_tags[tok_i] == .keyword_inline) {
         result.inline_token = tok_i;
-        tok_i -= 1;
+        tok_i -|= 1;
     }
     if (token_tags[tok_i] == .colon and
-        token_tags[tok_i - 1] == .identifier)
+        token_tags[tok_i -| 1] == .identifier)
     {
         result.label_token = tok_i - 1;
     }
diff --git a/lib/std/zig/parser_test.zig b/lib/std/zig/parser_test.zig
index ca3e99b164..00c50525a3 100644
--- a/lib/std/zig/parser_test.zig
+++ b/lib/std/zig/parser_test.zig
@@ -272,6 +272,17 @@ test "zig fmt: top-level enum missing 'const name ='" {
     , &[_]Error{.expected_token});
 }
 
+test "zig fmt: top-level for/while loop" {
+    try testCanonical(
+        \\for (foo) |_| foo
+        \\
+    );
+    try testCanonical(
+        \\while (foo) |_| foo
+        \\
+    );
+}
+
 test "zig fmt: top-level bare asterisk+identifier" {
     try testCanonical(
         \\*x