From f7e9d5b43e72439f5841f9ff5ef690a625fd312c Mon Sep 17 00:00:00 2001
From: Haojian Wu <hokein.wu@gmail.com>
Date: Sat, 7 Jan 2023 22:59:50 +0100
Subject: [PATCH] [clangd] Fix an inlay-hint crash on a null deduced type.

---
 clang-tools-extra/clangd/InlayHints.cpp               | 3 ++-
 clang-tools-extra/clangd/unittests/InlayHintTests.cpp | 7 ++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/clang-tools-extra/clangd/InlayHints.cpp b/clang-tools-extra/clangd/InlayHints.cpp
index 30c7c05e3c02..f4e38aeb653e 100644
--- a/clang-tools-extra/clangd/InlayHints.cpp
+++ b/clang-tools-extra/clangd/InlayHints.cpp
@@ -671,7 +671,8 @@ private:
     if (QT->isDecltypeType())
       return true;
     if (const AutoType *AT = QT->getContainedAutoType())
-      if (AT->getDeducedType()->isDecltypeType())
+      if (!AT->getDeducedType().isNull() &&
+          AT->getDeducedType()->isDecltypeType())
         return true;
     return false;
   }
diff --git a/clang-tools-extra/clangd/unittests/InlayHintTests.cpp b/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
index 53621f97a604..06f2c055a4d3 100644
--- a/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
+++ b/clang-tools-extra/clangd/unittests/InlayHintTests.cpp
@@ -1378,11 +1378,16 @@ TEST(TypeHints, Decltype) {
     using G = Foo<$g[[decltype(0)]], float>;
 
     auto $h[[h]] = $i[[decltype(0)]]{};
+
+    // No crash
+    /* error-ok */
+    auto $j[[s]];
   )cpp",
                   ExpectedHint{": int", "a"}, ExpectedHint{": int", "b"},
                   ExpectedHint{": int", "c"}, ExpectedHint{": int", "e"},
                   ExpectedHint{": int", "f"}, ExpectedHint{": int", "g"},
-                  ExpectedHint{": int", "h"}, ExpectedHint{": int", "i"});
+                  ExpectedHint{": int", "h"}, ExpectedHint{": int", "i"},
+                  ExpectedHint{": auto", "j"});
 }
 
 TEST(DesignatorHints, Basic) {