1195123 - Pull "!" inverting operator out of logic in SVG-image rejection code, to make it clearer that it matches the comment

Status: RESOLVED FIXED

(Core :: SVG, defect)

Description

[Daniel Holbert [:dholbert]]

As noted in bug 693940 comment 37, and bug 693940 comment 39, we've got some code for rejecting SVG images which is the inverse of the comment that describes it.

(The comment describes what's accepted; the code tests for what's rejected.)

This could be made clearer by pulling the "!" out of the code, so that we effectively have:
 if (!(accepted)) {
   reject;

Then it's easier to audit that the code matches the comment.

Comment 1

[Daniel Holbert [:dholbert]]

[er, somehow ended up with an arbitrary component. Sorry; --> SVG]

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: fix v1

So this patch changes:
 if (!A || (!B && !C))
...to:
 if (!(A && (B || C))
...which are be equivalent by the laws of logic and how "!" is applied to a complex expression.

Comment 3

[Daniel Holbert [:dholbert]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=f3c16ab74123

Comment 4

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/1563c2cabdc8

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/1563c2cabdc8