Lately, the right-click context menu in Slackware64-current Firefox (60.0.2) has been acting up. Right-clicking and releasing without moving the mouse results in going back a page. Right-clicking and holding down the button reveals that the mouse is positioned over the "left arrow" back button in the top-left of the menu, then releasing causes back to be selected.

Right-clicking and moving over another selectable item causes that item to be selected immediately upon mouse release. Right-clicking and moving over a non-selectable item (grayed out item or the name of a submenu) or outside the menu before releasing causes the menu to stay posted, at which point it can be used like a normal menu. Everything mentioned in this paragraph is fine, but I'm just spelling it out to explore the other possibilities.

The one thing that's wrong with this picture is that right-clicking (without moving the mouse) and releasing goes back one page. My expectation is that the menu to stay posted so I can click again on the item I want.

Anyone else have this issue? What can be done about it? Is it a misconfiguration on my part? I haven't experienced this in the Windows versions of Firefox.

Weird! It's doing that for me now. Before (32- bit; I just switched to 64-bit Linux.) it opened a new tab on the exact same page; before that it worked. I asked at Mozilla's forum but didn't get a useful response; no one else seemed to have the problem. I almost always get better support for Firefox there than LQ: it's worth asking.

Not seeing this. Normal mouse behavior here with Slackware64-current (Sat Jun 16 05:59:57 UTC 2018) Firefox (60.0.2)

It's also not a problem for me if I right-click on a new tab for which there is no history, but only because back is an inactive item.

Right-clicking on a link gives different behavior. It causes the link to be opened in a new tab since that item is what happens to end up under the mouse pointer when the menu is posted.

Please confirm that the back button is shown directly under the mouse pointer when you right-click, that it is not inactive, and that it still doesn't get selected.

Comparing Firefox with other applications, I see that everything else that has a right-click menu positions it slightly away from the mouse pointer, for example with the very corner of the menu frame at the pointer, with none of the menu items actually overlapping it. I strongly suspect this difference is the root of the problem, since normal behavior is for releasing the mouse button to select the item under the mouse pointer, or to leave the menu posted if the mouse button is released when not pointing at an enabled menu item.

In light of that observation, please also check where the menu is posted relative to the mouse pointer. To be clear, mine is positioned such that the back button's exact center aligns with the mouse pointer. This same offset is applied to other Firefox right-click menus, such as right-clicking in a multi-line text entry, despite the fact that the other menus don't have a back button.

I tested this out as you outlined. As you noted with other programs the mouse is slightly offset (top left) from the context menu. This is what I am seeing. Here are two screen shots. I can right click multiple times, the only thing that happens (as expected) is the context menu open and closes. If the right click is near the bottom of the page the mouse is positioned offset at the bottom left.

I am running Slackware64-current with Alien Bob's ktown. I also tested this on a clean version of Slackware64-current with KDE4

You did not mention your desktop.

I have no idea at the moment aside from maybe the mouse has sensitivity issues.

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Thanks. That's definitely normal behavior, and now I'm convinced my problem can be traced to the right-click menu being posted with the mouse pointer positioned over a menu item. But why that is happening is still unclear.

I am using xfce4. I'll try again with KDE when I finish updating to the latest Slackware64-current, though I'm not using ktown.

Just tried a fresh Slackware-14.2 32-bit install (on a Compaq Armada M300 from 2000 with 192 megabytes RAM, woo!) and am not experiencing the mouse problem in Firefox 45.2.0. Later I will upgrade it to the latest Slackware-current and repeat the test.

I will probably have to wait until tonight or tomorrow to do these tests because I have other work to do.

Only Firefox is affected.

I tried all the available window managers. Most worked fine, positioning the menu's corner at the mouse pointer. Some shifted the menu vertically but not horizontally, so the mouse pointer was at the extreme left of the back button, just outside of activation range. xfce and mwm put the menu's back button under the pointer, causing the problem. KDE put the menu corner at the mouse pointer, but with just a pixel or two of overlap so that right-clicking actually triggers the back button.

Digression: I noticed that with twm, right-clicking very quickly caused the menu to flicker onscreen briefly then go away, whereas holding the right mouse button for a few milliseconds longer caused the menu to post normally.

Bottom line: there's a lot of variation between window managers.

More information: Right click automatically clicks first menu item (on the right click menu popup).

However, I'm not using the Theme Font & Size Changer extension, even if the symptom is the same. I tried changing the "density" using the customize panel, and that didn't have an effect. I also tried safe mode, and it didn't fix anything. That part is definitely at odds with the linked report, in which safe mode corrected the issue.

I'm guessing the variation in window managers has to do with the extent each window manager will honor Firefox's attempt to position the menu, but it's really Firefox's problem that it be asking to put the menu under the mouse pointer.

Try moving your ~/.mozilla directory out of the way and let firefox create a new profile for testing.

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That fixed it. I then experimented with each of the customizations I'd previously applied, putting them in one-by-one. This narrowed it down to me having unchecked Title Bar in the customization panel. That's what's confusing all the menu coordinate offsets. This also explains the differences between window managers, since that option only works for some, and on those that do (which, if I remember right, are also the ones that get the menu position wrong), the offset of the menu varies, since different window managers also have different window border geometries.

We can experiment more, though I think it may be worthwhile to file a bug report now that we have a procedure to reproduce. Thanks for the suggestion!

Tried that, definitely affects the cursor position, however in my case, moved it further off from the context menu by quite a bit. Perhaps it's more that one setting. Strange problem indeed.

Edit: I looks more like it moved the context menu lower rather than effecting the cursor position. Position to the left looks about the same.

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Mine was checked; unchecking it made Firefox work 'properly'.

With Firefox 6.1.0esr, this is no longer an issue. I can disable the titlebar and still get the menus in the right place.

I'm experiencing this problem (though I would rather call it a feature) on Xfce with titlebar turned off, but not on i3 regardless of the position of the titlebar

Firefox version is 64

Related bug report: https://bugzilla.mozilla.org/show_bug.cgi?id=1504021

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