From 99fae47c8e6dc5d2a97291c0cb77a6047f8c81e8 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Wed, 5 May 2021 13:19:55 +0200
Subject: [PATCH] [Regression] Move the `super`-call in the
 `PredictorStream`-constructor to prevent errors (PR 13303)

*My apologies for breaking this; thankfully PR 13303 hasn't reach mozilla-central yet.*

It's (obviously) necessary to initialize a `PredictorStream`-instance fully, since otherwise breakage may occur if there's errors during the actual stream parsing.
To reproduce this issue, try opening the PDF document from issue 13051 locally and observe the following message in the console:
```
Warning: Invalid stream: "ReferenceError: this hasn't been initialised - super() hasn't been called"
```
---
 src/core/predictor_stream.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/core/predictor_stream.js b/src/core/predictor_stream.js
index 9a682f7e0..b04765ff5 100644
--- a/src/core/predictor_stream.js
+++ b/src/core/predictor_stream.js
@@ -19,10 +19,12 @@ import { isDict } from "./primitives.js";
 
 class PredictorStream extends DecodeStream {
   constructor(str, maybeLength, params) {
+    super(maybeLength);
+
     if (!isDict(params)) {
       return str; // no prediction
     }
-    const predictor = params.get("Predictor") || 1;
+    const predictor = (this.predictor = params.get("Predictor") || 1);
 
     if (predictor <= 1) {
       return str; // no prediction
@@ -30,8 +32,6 @@ class PredictorStream extends DecodeStream {
     if (predictor !== 2 && (predictor < 10 || predictor > 15)) {
       throw new FormatError(`Unsupported predictor: ${predictor}`);
     }
-    super(maybeLength);
-    this.predictor = predictor;
 
     if (predictor === 2) {
       this.readBlock = this.readBlockTiff;