Console "Discard Old Duplicates" doesn't apply in Windows Terminal

[stanio]

Windows Terminal version

1.14.1861.0

Windows build number

10.0.19043.1826

Other Software

No response

Steps to reproduce

• Open a legacy "Command Prompt" console;

• From the window menu (top-right icon) select "Defaults";

• Check "Discard Old Duplicates" in the "Command History" options group, and "OK" to apply;

  

• Open a "Command Prompt" in Windows Terminal, and enter commands in succession:

  dir
  dir /b
  dir
  dir /b
  dir
  dir /b
  

Expected Behavior

The command buffer should discard previous duplicate entries, as I'm seeing in a legacy "Command Prompt" console – pressing F7 reveals:

Actual Behavior

The "Command Prompt" in Windows Terminal doesn't appear to honor the "Discard Old Duplicates" setting – pressing F7 reveals:

This often causes the inconvenience of losing previous command history, after repeating a few of the same commands in succession for some time.

[stanio]

FWIW, I'm not sure this is a Windows Terminal issue, as I'm noticing every time I open the (legacy) "Console Windows Properties" I'm seeing the "Discard Old Duplicates" setting unchecked while I'm seeing "HistoryNoDup"=dword:00000001 in the Windows Registry:

I'm observing this UI(?) quirk on at least two Windows 10 machines.

[stanio]

More details – if I repeat just the same last command, it doesn't get multiplied to the end of the command history:

>dir
>dir /b
>dir
>dir
>dir

F7 (doskey /?):

┌────────────────────────────────────────┐
│0: dir                                  │
│1: dir /b                               │
│2: dir                                  │
│                                        │
│                                        │
│                                        │
│                                        │
│                                        │
│                                        │
│                                        │
└────────────────────────────────────────┘

So it is likely a half-baked port of the original "Discard Old Duplicates" implementation.

My workflow involves repeating 2-3 commands (build, deploy, cls) for some time. After that, I want to quickly select and execute some other command(s) I've executed previously. The current behavior breaks it for me.

[zadjii-msft]

This is probably another face of #2558. When run in ConPTY (read: the terminal), the console just ignores most settings. That might have been a mis-play. We may want to keep around the history settings, but just ignore the "appearance" ones.

Ultimately, this has the same root cause as that issue, so I'm gonna close it as a dupe for bookkeeping purposes. Thanks!

/dup #2558

[stanio]

Just want to clarify my problem is not that the Windows Terminal doesn't appear to obey the "Discard Old Duplicates" option. It appears to implement some form of it – "discards" just the last command if it matches the previous one. It might be doing it by default, not obeying the original setting (haven't verified explicitly) but this issue is about not matching the original "Discard Old Duplicates" behavior. I suspect even if the setting is read from the Console, the Terminal behavior might still be left broken (at least for me).

[DHowett]

Yeah, I think this one is worth tracking. Even in its default configuration (read: enabled) it doesn't do what it says on the tin.