libclang: fix a crash in clang_disposeDiagnosticSet when it is passed a NULL argument

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@201236 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/tools/libclang/CIndexDiagnostic.cpp b/tools/libclang/CIndexDiagnostic.cpp
index 0c327f611a2b4c3af4308800d97555173f9392bf..d3450d5dece7c1f237c78fdf563231c166d1c64c 100644 (file)
--- a/tools/libclang/CIndexDiagnostic.cpp
+++ b/tools/libclang/CIndexDiagnostic.cpp
@@ -450,9 +450,10 @@ CXString clang_getDiagnosticFixIt(CXDiagnostic Diag, unsigned FixIt,
 }
 
 void clang_disposeDiagnosticSet(CXDiagnosticSet Diags) {
-  CXDiagnosticSetImpl *D = static_cast<CXDiagnosticSetImpl*>(Diags);
-  if (D->isExternallyManaged())
-    delete D;
+  if (CXDiagnosticSetImpl *D = static_cast<CXDiagnosticSetImpl *>(Diags)) {
+    if (D->isExternallyManaged())
+      delete D;
+  }
 }
   
 CXDiagnostic clang_getDiagnosticInSet(CXDiagnosticSet Diags,