Bug 492518

SUMMARY
I use Kcalc many times every day. It worked great. I use it in Simple mode. When they added the history display, I started using it from flatpaks to get that feature in older releases of Kubuntu.

On Kubuntu 22.04, I am using Kcalc 23.04.3. It works exactly the way it used to - which is what I want.

On Kubuntu 18.04, I’m using Kcalc 24.05.2. It does not work as expected or desired.

I have no idea why I have different versions on the two notebooks. AFAIK, I installed them the same way.

On the old version, if I enter 1 * 2 =, the answer, 2 appears in the register. Clicking on the register copies it to my clipboard. Entering another digit clears the register and replaces it with the new digit. The old calculation and results are automatically out of the way.

On the new version, if I enter 1 * 2 =, 2 appears in a new space below the register and then disappears from that space and 2 appears in the register. Clicking on the register appears to do nothing. I have to double or triple click on it to select it and then press Ctrl+C to copy it to my clipboard. This is bad. But far worse, if I next type a 3, instead of the register containing 3, it appends the 3 and the register contains 23. This means I have to clear the register every time before I use it.

I have never seen a calculator that does this and don’t want to!

What is going on? Do I have to find a way to get and pin the old version?

Why was this done?

STEPS TO REPRODUCE
1. On the new version, if I enter 1 * 2 =, 2 appears in a new space below the register and then disappears from that space and 2 appears in the register.
2. Clicking on the register appears to do nothing. I have to double or triple click on it to select it and then press Ctrl+C to copy it to my clipboard.
3.  if I next type a 3, instead of the register containing 3, it appends the 3 and the register contains 23.

OBSERVED RESULT
Copying to the clipboard is much harder to do
Have to manually clear the register before the next independent calculation or it appends the new input to the old answer.
If I don't press =, I can click on the new line below the register and copy it, but then the calculation doesn't get added to the history unless I press = afterwards. Doesn't make any sense.

EXPECTED RESULT
Should work exactly as it did in Kcalc 23.04.3
Single clicking on the register copies to the clipboard
Anything typed after an equal sign replaces the contents of the register
If I want to continue using the current result, I should have to press an operator key after pressing =.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: Kubuntu 18.04 KDE (in a flatpak)
KDE Plasma Version: ??? (whatever the flatpak uses)
KDE Frameworks Version: 6.5.0
Qt Version: 6.7.2

ADDITIONAL INFORMATION
The new version is very unnatural to use and very mistake prone. The old version works great.