BinaryPrinter._getVariableIndex crash

[Hixie]

This rather dubious code:

test(x) => x();

void main() {
  test(bar() { print(bar); });
}

...causes this crash when run using dart test.dart:

ianh@burmese:~/dev/scratch$ dart test.dart
Null check operator used on a null value
#0      BinaryPrinter._getVariableIndex (package:kernel/binary/ast_to_binary.dart:83:17)
#1      BinaryPrinter.visitVariableGet (package:kernel/binary/ast_to_binary.dart:1497:17)
#2      VariableGet.accept (package:kernel/ast.dart:4144:44)
#3      BinaryPrinter.writeNode (package:kernel/binary/ast_to_binary.dart:430:10)
#4      BinaryPrinter.writeNodeList (package:kernel/binary/ast_to_binary.dart:340:7)
#5      BinaryPrinter.visitArguments (package:kernel/binary/ast_to_binary.dart:1777:5)
#6      Arguments.accept (package:kernel/ast.dart:5316:38)
#7      BinaryPrinter.writeArgumentsNode (package:kernel/binary/ast_to_binary.dart:444:10)
#8      BinaryPrinter.visitStaticInvocation (package:kernel/binary/ast_to_binary.dart:1760:5)
#9      StaticInvocation.accept (package:kernel/ast.dart:6601:44)
#10     BinaryPrinter.writeNode (package:kernel/binary/ast_to_binary.dart:430:10)
#11     BinaryPrinter.visitExpressionStatement (package:kernel/binary/ast_to_binary.dart:2079:5)
#12     ExpressionStatement.accept (package:kernel/ast.dart:9141:43)
#13     BinaryPrinter.writeNode (package:kernel/binary/ast_to_binary.dart:430:10)
#14     BinaryPrinter.writeNodeList (package:kernel/binary/ast_to_binary.dart:340:7)
#15     BinaryPrinter.visitBlock (package:kernel/binary/ast_to_binary.dart:2090:5)
#16     Block.accept (package:kernel/ast.dart:9197:43)
#17     BinaryPrinter.writeNode (package:kernel/binary/ast_to_binary.dart:430:10)
#18     BinaryPrinter.writeOptionalNode (package:kernel/binary/ast_to_binary.dart:522:7)
#19     BinaryPrinter.visitFunctionNode (package:kernel/binary/ast_to_binary.dart:1481:5)
#20     FunctionNode.accept (package:kernel/ast.dart:3846:38)
#21     BinaryPrinter.writeFunctionNode (package:kernel/binary/ast_to_binary.dart:437:10)
#22     BinaryPrinter.visitFunctionExpression (package:kernel/binary/ast_to_binary.dart:2023:5)
#23     FunctionExpression.accept (package:kernel/ast.dart:8592:44)
#24     BinaryPrinter.writeNode (package:kernel/binary/ast_to_binary.dart:430:10)
#25     BinaryPrinter.writeOptionalNode (package:kernel/binary/ast_to_binary.dart:522:7)
#26     BinaryPrinter.writeVariableDeclaration (package:kernel/binary/ast_to_binary.dart:2293:5)
#27     BinaryPrinter.visitLet (package:kernel/binary/ast_to_binary.dart:2033:5)
#28     Let.accept (package:kernel/ast.dart:8703:44)
#29     BinaryPrinter.writeNode (package:kernel/binary/ast_to_binary.dart:430:10)
#30     BinaryPrinter.writeNodeList (package:kernel/binary/ast_to_binary.dart:340:7)
#31     BinaryPrinter.visitArguments (package:kernel/binary/ast_to_binary.dart:1777:5)
#32     Arguments.accept (package:kernel/ast.dart:5316:38)
#33     BinaryPrinter.writeArgumentsNode (package:kernel/binary/ast_to_binary.dart:444:10)
#34     BinaryPrinter.visitStaticInvocation (package:kernel/binary/ast_to_binary.dart:1760:5)
#35     StaticInvocation.accept (package:kernel/ast.dart:6601:44)
#36     BinaryPrinter.writeNode (package:kernel/binary/ast_to_binary.dart:430:10)
#37     BinaryPrinter.visitExpressionStatement (package:kernel/binary/ast_to_binary.dart:2079:5)
#38     ExpressionStatement.accept (package:kernel/ast.dart:9141:43)
#39     BinaryPrinter.writeNode (package:kernel/binary/ast_to_binary.dart:430:10)
#40     BinaryPrinter.writeNodeList (package:kernel/binary/ast_to_binary.dart:340:7)
#41     BinaryPrinter.visitBlock (package:kernel/binary/ast_to_binary.dart:2090:5)
#42     Block.accept (package:kernel/ast.dart:9197:43)
#43     BinaryPrinter.writeNode (package:kernel/binary/ast_to_binary.dart:430:10)
#44     BinaryPrinter.writeOptionalNode (package:kernel/binary/ast_to_binary.dart:522:7)
#45     BinaryPrinter.visitFunctionNode (package:kernel/binary/ast_to_binary.dart:1481:5)
#46     FunctionNode.accept (package:kernel/ast.dart:3846:38)
#47     BinaryPrinter.writeFunctionNode (package:kernel/binary/ast_to_binary.dart:437:10)
#48     BinaryPrinter.visitProcedure (package:kernel/binary/ast_to_binary.dart:1312:5)
#49     Procedure.accept (package:kernel/ast.dart:3151:40)
#50     BinaryPrinter.writeProcedureNode (package:kernel/binary/ast_to_binary.dart:458:10)
#51     BinaryPrinter.writeProcedureNodeList (package:kernel/binary/ast_to_binary.dart:349:7)
#52     BinaryPrinter.visitLibrary (package:kernel/binary/ast_to_binary.dart:1063:5)
#53     Library.accept (package:kernel/ast.dart:565:38)
#54     BinaryPrinter.writeLibraryNode (package:kernel/binary/ast_to_binary.dart:451:10)
#55     BinaryPrinter.writeLibraries (package:kernel/binary/ast_to_binary.dart:756:9)
#56     BinaryPrinter.writeComponentFile.<anonymous closure> (package:kernel/binary/ast_to_binary.dart:595:7)
#57     Timeline.timeSync (dart:developer/timeline.dart:160:22)
#58     BinaryPrinter.writeComponentFile (package:kernel/binary/ast_to_binary.dart:577:14)
#59     serializeComponent (package:front_end/src/fasta/kernel/utils.dart:94:11)
#60     _processLoadRequest (file:///b/s/w/ir/cache/builder/sdk/pkg/vm/bin/kernel_service.dart:910:13)
<asynchronous suspension>