1428753 - Zooming in on an image causes the cursor to change into a magnifying-glass with wrong symbols.

Status: RESOLVED FIXED

(Core :: Layout: Images, Video, and HTML Frames, defect, P3)

Description

[Oana Botisan, Desktop QA]

[Affected versions]:
- Latest Nightly 59 
- Beta 58.0b14
- Firefox 57.0.4

[Affected platforms]:
- Windows 10 x64
- macOS 10.13

[Steps to reproduce]:
1. Launch Firefox and open an image (ex. http://www.catster.com/wp-content/uploads/2017/08/A-fluffy-cat-looking-funny-surprised-or-concerned.jpg)
2. Use Ctrl+scroll to zoom in until the image is bigger than the browser window
3. Observe the cursor's behaviour.

[Expected result]:
- When you zoom in the cursor changes into magnifying-glass with "-" symbol. (I think this is the expected behaviour because it zooms out when you click on the image.)

[Actual result]:
- It alternates between the magnifying-glass with "+" symbol and the one with "-" symbol. If you click then the image rescales to the original size. 

[Regression range]:
- I can't find exactly when this problem first started because at some point the issue was that only the magnifying-glass with "+" symbol appeared. 

[Additional notes]:
- To see the issue please look at the attached screen recording.
- I've notice that this issue is reproducible for a lot of image formats: .jpg, .bmp, .gif etc. The only format that is not affected is .jpeg, as far as I can tell. 
-

Comment 1

[Jet Villegas (inactive)]

[ Triage 2017/02/20: P3 ]

Comment 2

[Daniel Almeida]

Please assign

Comment 3

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1428753: Ensure that vertical-overflowing images always show the zoom-out cursor.

Review commit: https://reviewboard.mozilla.org/r/236148/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/236148/

Comment 4

[Cameron McCormack (:heycam)]

Comment on attachment 8967486 [details]
Bug 1428753: Ensure that vertical-overflowing images always show the zoom-out cursor.

https://reviewboard.mozilla.org/r/236148/#review242096

Makes sense, thanks.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/260e4c83c8a9
Ensure that vertical-overflowing images always show the zoom-out cursor. r=heycam

Comment 6

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/260e4c83c8a9

Comment 7

[Cristian Baica [:cbaica], Release Desktop QA]

I have managed to reproduce this issue on Win 7x64, using Fx61.0b4. The magnifying glass has the '+' symbol the first time the picture is bigger than the browser window. If the zoom in is continued, the magnifying glass turns to '-' until the max zoom in is reached.
Please note that this occurs intermittently.