[clang] [clang-format] Fix a bug in ContinuationIndenter (PR #66354)

[Owen Pan via cfe-commits]

https://github.com/owenca created https://github.com/llvm/llvm-project/pull/66354:

See https://reviews.llvm.org/D136154#3890747 for context.

Fixes part of #58592.

>From 9a15ec3256e2d380d5eb70f0751ea1bb457895dd Mon Sep 17 00:00:00 2001
From: Owen Pan <owenpiano at gmail.com>
Date: Thu, 14 Sep 2023 02:59:43 -0700
Subject: [PATCH] [clang-format] Fix a bug in ContinuationIndenter

See https://reviews.llvm.org/D136154#3890747 for context.

Fixes part of #58592.
---
 clang/lib/Format/ContinuationIndenter.cpp |  5 +++--
 clang/unittests/Format/FormatTest.cpp     | 23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index 75ab08de42ea0e8..8f14105751daefa 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -876,8 +876,9 @@ void ContinuationIndenter::addTokenOnCurrentLine(LineState &State, bool DryRun,
                  FormatStyle::BCIS_AfterColon) {
     CurrentState.Indent = State.Column;
     CurrentState.LastSpace = State.Column;
-  } else if ((Previous.isOneOf(TT_BinaryOperator, TT_ConditionalExpr,
-                               TT_CtorInitializerColon)) &&
+  } else if (Previous.isOneOf(TT_ConditionalExpr, TT_CtorInitializerColon)) {
+    State.Stack.back().LastSpace = State.Column;
+  } else if (Previous.is(TT_BinaryOperator) &&
              ((Previous.getPrecedence() != prec::Assignment &&
                (Previous.isNot(tok::lessless) || Previous.OperatorIndex != 0 ||
                 Previous.NextOperator)) ||
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 4f72166bdce2d73..0d0fbdb84e3271b 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -7108,6 +7108,29 @@ TEST_F(FormatTest, ExpressionIndentationBreakingBeforeOperators) {
                "(someOtherLongishConditionPart1 || "
                "someOtherEvenLongerNestedConditionPart2);",
                Style);
+
+  Style = getLLVMStyleWithColumns(20);
+  Style.AlignAfterOpenBracket = FormatStyle::BAS_AlwaysBreak;
+  Style.BinPackParameters = false;
+  Style.BreakBeforeBinaryOperators = FormatStyle::BOS_NonAssignment;
+  Style.ContinuationIndentWidth = 2;
+  verifyFormat("struct Foo {\n"
+               "  Foo(\n"
+               "    int arg1,\n"
+               "    int arg2)\n"
+               "      : Base(\n"
+               "          arg1,\n"
+               "          arg2) {}\n"
+               "};",
+               Style);
+  verifyFormat("return abc\n"
+               "         ? foo(\n"
+               "             a,\n"
+               "             b,\n"
+               "             bar(\n"
+               "               abc))\n"
+               "         : g(abc);",
+               Style);
 }
 
 TEST_F(FormatTest, ExpressionIndentationStrictAlign) {