Comment 6 for bug 1831264

Although reported to gitlab.freedesktop.org (see above), there is no sign whatsoever of activity in that quarter.
In the meantime, I have just downloaded the latest batch of 18.04 updates, and the situation has got immeasurably worse.

The relevant part of the xmodmap -pk output has now changed to:

    136 0xffc8 (F11) 0xffc8 (F11) 0xffc8 (F11) 0xffc8 (F11) 0xff69 (Cancel) 0x0000 (NoSymbol) 0xff69 (Cancel)
    137 0xffc9 (F12) 0xffc9 (F12) 0xffc9 (F12) 0xffc9 (F12) 0xff66 (Redo) 0x0000 (NoSymbol) 0xff66 (Redo)
    138 0xffca (F13) 0xffca (F13) 0xffca (F13) 0xffca (F13) 0x1005ff70 (SunProps) 0x0000 (NoSymbol) 0x1005ff70 (SunProps)
    139 0xffcb (F14) 0xffcb (F14) 0xffcb (F14) 0xffcb (F14) 0xff65 (Undo) 0x0000 (NoSymbol) 0xff65 (Undo)
    140 0xffcc (F15) 0xffcc (F15) 0xffcc (F15) 0xffcc (F15) 0x1005ff71 (SunFront) 0x0000 (NoSymbol) 0x1005ff71 (SunFront)
    141 0xffcd (F16) 0xffcd (F16) 0xffcd (F16) 0xffcd (F16) 0x1005ff72 (SunCopy) 0x0000 (NoSymbol) 0x1005ff72 (SunCopy)
    142 0xffce (F17) 0xffce (F17) 0xffce (F17) 0xffce (F17) 0x1005ff73 (SunOpen) 0x0000 (NoSymbol) 0x1005ff73 (SunOpen)
    143 0xffcf (F18) 0xffcf (F18) 0xffcf (F18) 0xffcf (F18) 0x1005ff74 (SunPaste) 0x0000 (NoSymbol) 0x1005ff74 (SunPaste)
    144 0xffd0 (F19) 0xffd0 (F19) 0xffd0 (F19) 0xffd0 (F19) 0xff68 (Find) 0x0000 (NoSymbol) 0xff68 (Find)
    145 0xffd1 (F20) 0xffd1 (F20) 0xffd1 (F20) 0xffd1 (F20) 0x1005ff75 (SunCut) 0x0000 (NoSymbol) 0x1005ff75 (SunCut)
    146 0xff6a (Help) 0x0000 (NoSymbol) 0xff6a (Help)

i.e. the keysyms mapped to keycodes 141, 142, 143, and 145 have all changed, and unpteen things which were working fine this morning are suddenly broken (in addition to gedit, which I can fix, my Opera Browser is affected' libreoffice and firefox seem to have survived, but every application whatsoever, when you press keycode 145, produces an ugly popup concerning my "rear microphone" - which does not even exist).

What is going on?