308734 - Limit the values we accept for currentScale

Status: RESOLVED FIXED

(Core :: SVG, defect)

Description

[Jonathan Watt [:jwatt]]

We need to put limits on the values we allow for currentScale. Playing with

http://jwatt.org/svg/tests/zoom-and-pan-controls.svg

shows that you don't have to zoom in or out too many times before nasty
artifacts and maxing out of CPU and memory occurs. ASV allows for a maximum
value of 16 and a minimum value of 0.0625. Unless anyone has other ideas, I
suggest we use these limits too.

Comment 1

[Jonathan Watt [:jwatt]]

Attachment: patch

This patch keeps currentScale clamped to what are hopefully safe values.

For the record I tried doing this in WillModify/DidModify, but it isn't
possible. Once you get past the first issues (hint - recursion) you find that
it's impossible to dispatch event's with the correct data when you need to
clamp.

Comment 2

[Jonathan Watt [:jwatt]]

Comment on attachment 196276 [details] [diff] [review]
patch

Requesting approval. It's very important that we include this in FF1.5. The
risk is next to nothing.

Comment 3

[Asa Dotzler [:asa]]

Comment on attachment 196276 [details] [diff] [review]
patch

we're now locked down and in ship mode for 1.8b5. If you'd like to re-request
approval for this change, please set the approval1.8rc1? flag.

Comment 4

[Jonathan Watt [:jwatt]]

Sorry Asa, this is actually already landed. I just forgot to add the fixed1.8
keyword.