SI-7185 Avoid NPE in TreeInfo.isExprSafeToInline

We got there typechecking code with a redundant
layer of Block.

We can't express that in source code, so we test
this with manual tree construction and with XML
literals, which as reported produce such trees.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/reflect/scala/reflect/internal/TreeInfo.scala b/src/reflect/scala/reflect/internal/TreeInfo.scala
index 3040486076..3e74b5d22d 100644
--- a/src/reflect/scala/reflect/internal/TreeInfo.scala
+++ b/src/reflect/scala/reflect/internal/TreeInfo.scala
@@ -98,7 +98,8 @@ abstract class TreeInfo {
       // However, before typing, applications of nullary functional values are also
       // Apply(function, Nil) trees. To prevent them from being treated as pure,
       // we check that the callee is a method.
-      fn.symbol.isMethod && !fn.symbol.isLazy && isExprSafeToInline(fn)
+      // The callee might also be a Block, which has a null symbol, so we guard against that (SI-7185)
+      fn.symbol != null && fn.symbol.isMethod && !fn.symbol.isLazy && isExprSafeToInline(fn)
     case Typed(expr, _) =>
       isExprSafeToInline(expr)
     case Block(stats, expr) =>