Change Details

**Steps to Reproduce: ** 1. Use Chrome. 2. Visit any Wikimedia page that can be edited in visual mode (Wikipedia, Wikimedia Commons, etc.). I used the Wikipedia article https://en.wikipedia.org/wiki/DNA_methylation as an example. 3. Click "Edit" to edit the page. 4. Switch to visual editor if not already in it (by clicking the pencil then clicking "Visual editing"). 5. Hold the middle mouse button down and flick the cursor down in a quick motion to scroll down the page. The same can be repeated for up the page. Clicking the mousewheel then flicking the cursor works too. **Actual Results:** A split-second after the initiation of the scroll (usually about 500ms), the page snaps back to where it was originally. One must hold the scrollwheel down longer in order to let the page snap back and scroll down again to where the user wants. It does not occur with every scroll. Video: https://www.dropbox.com/s/jtjj1k1okegdmtt/Chrome%20Wikipedia%20Scrolling%20Bug.mp4?dl=0 **Expected Results:** The page should scroll down or up as per the user's direction, with no uncommanded movements. **Notes:** It started in approximately June 2019 and has never been fixed. It happens on Wiktionary, Wikimedia Commons, or any Wikimedia website that can use the VisualEditor. It does not happen in Firefox or IE. I also tested on a second, unrelated PC, and it happened on that PC's Chrome. It happens in a clean session of Chrome Canary 81.0.4036.0 (64-bit). I then tested on version of Chromium from May 2019, March 2019 and October 2018, and it occurred on all of them, proving it is a VisualEditor issue and not a Chrome issue, even though it only occurs in Chrome.

**Steps to Reproduce: ** 1. Use Chrome. 2. Visit any Wikimedia page that can be edited in visual mode (Wikipedia, Wikimedia Commons, etc.). I used the Wikipedia article https://en.wikipedia.org/wiki/DNA_methylation as an example. 3. Click "Edit" to edit the page. 4. Switch to visual editor if not already in it (by clicking the pencil then clicking "Visual editing"). 5. Hold the middle mouse button down and flick the cursor down in a quick motion to scroll down the page. The same can be repeated for up the page. Clicking the mousewheel then flicking the cursor works too. **Actual Results:** A split-second after the initiation of the scroll (usually about 500ms), the page snaps back to where it was originally. One must hold the scrollwheel down longer in order to let the page snap back and scroll down again to where the user wants. It does not occur with every scroll. Video: https://www.dropbox.com/s/jtjj1k1okegdmtt/Chrome%20Wikipedia%20Scrolling%20Bug.mp4?dl=0 **Expected Results:** The page should scroll down or up as per the user's direction, with no uncommanded movements. **Notes:** It started in approximately June 2019 and has never been fixed. It happens on Wiktionary, Wikimedia Commons and any Wikimedia website that can use the VisualEditor. It does not happen in Firefox or IE. I also tested on a second, unrelated PC, and it happened on that PC's Chrome. It happens in a clean session of Chrome Canary 81.0.4036.0 (64-bit). I then tested on version of Chromium from May 2019, March 2019 and October 2018, and it occurred on all of them, proving it is a VisualEditor issue and not a Chrome issue, even though it only occurs in Chrome.

**Steps to Reproduce: ** 1. Use Chrome. 2. Visit any Wikimedia page that can be edited in visual mode (Wikipedia, Wikimedia Commons, etc.). I used the Wikipedia article https://en.wikipedia.org/wiki/DNA_methylation as an example. 3. Click "Edit" to edit the page. 4. Switch to visual editor if not already in it (by clicking the pencil then clicking "Visual editing"). 5. Hold the middle mouse button down and flick the cursor down in a quick motion to scroll down the page. The same can be repeated for up the page. Clicking the mousewheel then flicking the cursor works too. **Actual Results:** A split-second after the initiation of the scroll (usually about 500ms), the page snaps back to where it was originally. One must hold the scrollwheel down longer in order to let the page snap back and scroll down again to where the user wants. It does not occur with every scroll. Video: https://www.dropbox.com/s/jtjj1k1okegdmtt/Chrome%20Wikipedia%20Scrolling%20Bug.mp4?dl=0 **Expected Results:** The page should scroll down or up as per the user's direction, with no uncommanded movements. **Notes:** It started in approximately June 2019 and has never been fixed. It happens on Wiktionary, Wikimedia Commons, or and any Wikimedia website that can use the VisualEditor. It does not happen in Firefox or IE. I also tested on a second, unrelated PC, and it happened on that PC's Chrome. It happens in a clean session of Chrome Canary 81.0.4036.0 (64-bit). I then tested on version of Chromium from May 2019, March 2019 and October 2018, and it occurred on all of them, proving it is a VisualEditor issue and not a Chrome issue, even though it only occurs in Chrome.