crop() works incorrectly when x = 0 and w = current image width

[tdobes]

Expected Behavior

Running crop() should result in a buffer of the appropriate length

Current Behavior

Running crop() results in a buffer with an incorrect length

Failure Information (for bugs)

There is a bug on this line:
https://github.com/oliver-moran/jimp/blob/master/packages/plugin-crop/src/index.js#L30

Specifically, it looks like we're shifting things left by 3 bits instead of 2 bits. Assuming that we have 4-byte pixels (RGB+alpha), we should only shift by 2 bits. (2**2 = 4)

Steps to Reproduce

$ node
> const Jimp = require('jimp');
undefined
> t = new Jimp(100, 100, 0x00000000);
<Jimp 100x100>
> t.bitmap.data.length == 4*100*100
true
> t.clone().crop(0, 0, 100, 50).bitmap.data.length == 4*100*50
false

(That last line should report true!)

Context

• Jimp Version: 0.6.0
• Operating System: Ubuntu Linux 18.04
• Node version: 8.14.0

Fix

I'm not going to hassle with making a pull-request since this is a one-line fix. Basically, change the bit shift to 2 instead of 2+1. Specifically, the line should read:
const end = (start + h * w) << 2;

[hipstersmoothie]

One line fixes are the best though ;)

[piyushkantm]

Hey, is this fixed and merged in/before 0.6.4

[hipstersmoothie]

🚀 Issue was released in v0.6.6 🚀