[NFC] Avoid potential null dereference.

[schittir]

Add a null check.

[llvmbot]

@llvm/pr-subscribers-clang-format

Author: None (schittir)

Changes

Add a null check.

---

Full diff: https://github.com/llvm/llvm-project/pull/126872.diff

1 Files Affected:

• (modified) clang/lib/Format/UnwrappedLineFormatter.cpp (+1-1)

diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
index 46545aa1f4c07..a5b30c85974c7 100644
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -1596,7 +1596,7 @@ static auto computeNewlines(const AnnotatedLine &Line,
     if (Line.startsWith(TT_NamespaceRBrace)) {
       if (Style.WrapNamespaceBodyWithEmptyLines == FormatStyle::WNBWELS_Never)
         Newlines = 1;
-      else if (!PreviousLine->startsWith(TT_NamespaceRBrace))
+      else if (PreviousLine && !PreviousLine->startsWith(TT_NamespaceRBrace))
         Newlines = std::max(Newlines, 2u);
     }
   }

[owenca]

@schittir please add a test case that would cause a crash without your patch.