[clang] [clang-format] Fix a bug in `BreakBeforeBinaryOperators: All` (PR #149695)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/149695

Fixes #149520

>From 00d145827caea33cbec8f49a03e4c8b56fc40e01 Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Sun, 20 Jul 2025 00:58:58 -0700
Subject: [PATCH] [clang-format] Fix a bug in `BreakBeforeBinaryOperators: All`

Fixes #149520
---
 clang/lib/Format/ContinuationIndenter.cpp | 1 +
 clang/unittests/Format/FormatTest.cpp     | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index 4010f7fbd25be..bf67f9e5fd241 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -560,6 +560,7 @@ bool ContinuationIndenter::mustBreak(const LineState &State) {
         return true;
     }
   } else if (Current.is(TT_BinaryOperator) && Current.CanBreakBefore &&
+             Current.getPrecedence() != prec::Assignment &&
              CurrentState.BreakBeforeParameter) {
     return true;
   }
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 0bc1c6d45656e..11d94e47e5b06 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -28375,6 +28375,11 @@ TEST_F(FormatTest, BreakAfterAttributes) {
   verifyFormat("[[nodiscard]]\n"
                "Foo& operator-(Foo&);",
                Style);
+
+  Style.BreakBeforeBinaryOperators = FormatStyle::BOS_All;
+  verifyFormat("[[deprecated]]\n"
+               "void f() = delete;",
+               Style);
 }
 
 TEST_F(FormatTest, InsertNewlineAtEOF) {