Segmentation Fault

I am running pdf.js to convert PDF to PNG. With the attached PDF i'm getting a segmentation fault that seems to be the problem with node-canvas.

Attach (recommended) or Link to PDF file here:
[Waves-WAVES-Whitepaper-error.pdf](https://github.com/Automattic/node-canvas/files/5619102/Waves-WAVES-Whitepaper-error.pdf)

Web browser and its version: Node.js version
PDF.js version: tested on 2.6.347 and 2.4.456
Steps to reproduce the problem:
Use the node.js pdf2png converter to convert the attached PDF (https://github.com/mozilla/pdf.js/blob/master/examples/node/pdf2png/pdf2png.js)

This will end in a segmentation fault. I installed segfault-handler and ran it again. this is the output.

Is there anybody who can help with this issue. It looks like this might be an issue with node-canvas. Is there another way to get more information on this than the segmentation error log below?

```
PID 70543 received SIGSEGV for address: 0x0
0 segfault-handler.node 0x0000000102f01010 _ZL16segfault_handleriP9__siginfoPv + 304
1 libsystem_platform.dylib 0x00007fff6d93a5fd _sigtramp + 29
2 ??? 0x0000ffff00001fa3 0x0 + 281470681751459
3 canvas.node 0x0000000104c1cc60 _ZN9Context2d4fillEb + 228
4 canvas.node 0x0000000104c13a3e _ZN9Context2d4FillERKN3Nan20FunctionCallbackInfoIN2v85ValueEEE + 264
5 canvas.node 0x0000000104c029c8 _ZN3Nan3impL23FunctionCallbackWrapperERKN2v820FunctionCallbackInfoINS1_5ValueEEE + 186
6 node 0x00000001001f40e8 _ZN2v88internal25FunctionCallbackArguments4CallENS0_15CallHandlerInfoE + 616
7 node 0x00000001001f36a9 _ZN2v88internal12_GLOBAL__N_119HandleApiCallHelperILb0EEENS0_11MaybeHandleINS0_6ObjectEEEPNS0_7IsolateENS0_6HandleINS0_10HeapObjectEEESA_NS8_INS0_20FunctionTemplateInfoEEENS8_IS4_EENS0_16BuiltinArgumentsE + 521
8 node 0x00000001001f2dd2 _ZN2v88internalL26Builtin_Impl_HandleApiCallENS0_16BuiltinArgumentsEPNS0_7IsolateE + 258
9 node 0x000000010097d6b9 Builtins_CEntry_Return1_DontSaveFPRegs_ArgvOnStack_BuiltinExit + 57
```