From 558deee9117ecf5760545a4eae2679087e3f4f2f Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano@gmail.com>
Date: Fri, 10 Oct 2025 19:31:55 -0700
Subject: [PATCH] [clang-format] Fix a bug in OneLineFormatOffRegex

Fixes #162402
---
 clang/lib/Format/FormatTokenLexer.cpp | 13 +++++++------
 clang/unittests/Format/FormatTest.cpp |  5 +++++
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/clang/lib/Format/FormatTokenLexer.cpp b/clang/lib/Format/FormatTokenLexer.cpp
index 3f4aa52a87d2e..b1f632a9bb483 100644
--- a/clang/lib/Format/FormatTokenLexer.cpp
+++ b/clang/lib/Format/FormatTokenLexer.cpp
@@ -93,12 +93,6 @@ ArrayRef<FormatToken *> FormatTokenLexer::lex() {
     auto &Tok = *Tokens.back();
     const auto NewlinesBefore = Tok.NewlinesBefore;
     switch (FormatOff) {
-    case FO_CurrentLine:
-      if (NewlinesBefore == 0)
-        Tok.Finalized = true;
-      else
-        FormatOff = FO_None;
-      break;
     case FO_NextLine:
       if (NewlinesBefore > 1) {
         FormatOff = FO_None;
@@ -107,6 +101,13 @@ ArrayRef<FormatToken *> FormatTokenLexer::lex() {
         FormatOff = FO_CurrentLine;
       }
       break;
+    case FO_CurrentLine:
+      if (NewlinesBefore == 0) {
+        Tok.Finalized = true;
+        break;
+      }
+      FormatOff = FO_None;
+      [[fallthrough]];
     default:
       if (!FormattingDisabled && FormatOffRegex.match(Tok.TokenText)) {
         if (Tok.is(tok::comment) &&
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index fef70365b5e18..450c34f111a8a 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -24843,6 +24843,11 @@ TEST_F(FormatTest, OneLineFormatOffRegex) {
                " } while (0 )",
                Style);
 
+  Style.OneLineFormatOffRegex = "MACRO_TEST";
+  verifyNoChange(" MACRO_TEST1 ( ) ;\n"
+                 "   MACRO_TEST2( );",
+                 Style);
+
   Style.ColumnLimit = 50;
   Style.OneLineFormatOffRegex = "^LogErrorPrint$";
   verifyFormat(" myproject::LogErrorPrint(logger, \"Don't split me!\");\n"