linewrap then backspace produces unexpected visuals, missing characters

[fredless]

Environment

Windows build number: Microsoft Windows [Version 10.0.18362.175]
Windows Terminal version (if applicable): built using d82eab4

Steps to reproduce

• open terminal with following profile:

{
    "globals" : 
    {
        "alwaysShowTabs" : false,
        "defaultProfile" : "{9d2406b9-7e40-4e2b-a20d-82dc61c4cc24}",
        "initialCols" : 80,
        "initialRows" : 60,
        "requestedTheme" : "dark",
        "showTabsInTitlebar" : true,
        "showTerminalTitleInTitlebar" : false
    },
    "profiles" : 
    [
        {
            "acrylicOpacity" : 0.80000001192092896,
            "closeOnExit" : true,
            "colorScheme" : "Solarized Dark",
            "commandline" : "cmd.exe",
            "cursorColor" : "#FFFFFF",
            "cursorShape" : "bar",
            "fontFace" : "Consolas",
            "fontSize" : 10,
            "guid" : "{9d2406b9-7e40-4e2b-a20d-82dc61c4cc24}",
            "historySize" : 9001,
            "name" : "cmd",
            "padding" : "0, 0, 0, 0",
            "snapOnInput" : true,
            "startingDirectory" : "%USERPROFILE%",
            "useAcrylic" : true
        }
    ]
}

• input characters until the line wraps, backspace once, and enter an additional character

Expected behavior

• Cursor should return to the previous position following the last character on the previous line after hitting backspace.
• Additional input character (sent after backspace) should show up after the last character on the previous line.

Actual behavior

• Cursor returns to previous line, but with a whitespace between the last character input and the cursor position
• Additional input character does not show up in terminal, although it is recognized

'..789ab' is received as input in the example below, even though it is not shown:

[DHowett-MSFT]

This is probably something down in the pseudoconsole layer; we probably have a duplicate for it, but we can't find it.

[fredless]

Should have also mentioned in case it may be helpful, identical behavior was observed on 73ad742

Didn't report then as that was my first exposure, assumed either I couldn't be the only one (or that I was). I just repulled and built in hopes it might have been squashed. I searched then and now before submitting but didn't see a specific match.

[fredless]

I can't be the only one.. can I?

[zadjii-msft]

@fredless you're not the only one - this is a reasonable bug report with clear repro steps. Doesn't seem like there's much that needs to be added until someone starts working on a fix.