Autosuggestions do not appear when cursor passes the fish_right_prompt

[tangmi]

$ fish --version
  echo $version
fish, version 3.1.0
3.1.0

$ uname -a
Darwin Mac.local 18.0.0 Darwin Kernel Version 18.0.0: Wed Aug 22 20:13:40 PDT 2018; root:xnu-4903.201.2~1/RELEASE_X86_64 x86_64

$ echo $TERM
xterm-256color

Hi, when I have a fish_right_prompt that is very long and type a command that overlaps it, the right prompt disappears (as expected!), but the autosuggestions on the command line stop appearing, as well.

Here is an example of what I'm trying to do:

function fish_prompt
    echo -n "\$ "
end

function fish_right_prompt
    set --local pwd (prompt_pwd)
    set --local prompt_len 2
    set --local rpadding (math -- $COLUMNS - (string length $pwd) - $prompt_len - 2)
    set_color $fish_color_autosuggestion
    echo -n $pwd(string repeat --count $rpadding " ")
    set_color normal
end

At a higher level, I'm trying to create a prompt that shows a "ghost" of $PWD until the user types (please let me know if there's a better way to do this!):

$ _ ~/code/fish-shell
  ^ ^
  | "ghost" of $PWD
  cursor position

$ ls
   ^ ^
   | "ghost" disappears
   user starts to type a command

Many thanks!

[ridiculousfish]

I think this was originally by design, although I can no longer remember the rationale. If someone would like to tackle this, screen.cpp compute_layout is the place to do it.

[ksralgp]

I have been interested in trying to make a contribution and via some debugging have small idea of how the layout computation works.

I saw this code in screen.cpp:

    // Here are the layouts we try in turn:
    // 1. Left prompt visible, right prompt visible, command line visible, autosuggestion visible.
    //
    // 2. Left prompt visible, right prompt visible, command line visible, autosuggestion truncated
    // (possibly to zero).
    //
    // 3. Left prompt visible, right prompt hidden, command line visible, autosuggestion hidden.
    //
    // 4. Newline separator (left prompt visible, right prompt hidden, command line visible,
    // autosuggestion visible).
    //
    // A remark about layout #4: if we've pushed the command line to a new line, why can't we draw
    // the right prompt? The issue is resizing: if you resize the window smaller, then the right
    // prompt will wrap to the next line. This means that we can't go back to the line that we were
    // on, and things turn to chaos very quickly.

which explains why autosuggestions are not shown because rendering option (3) is happening. @ridiculousfish is the suggestion to add another option that would sit between 2 and 3?

IE Left prompt visible, right prompt hidden, command line visible, autosuggestion visible

On a side-note the comment for (4) suggests autosuggestions should be displayed when the command line extends across multiple-lines. My observation in the code and using fish is currently autosuggesions are omitted. Should I open another issue for that?

[ridiculousfish]

Yeah that's the logic that computes the layout hierarchy. I think #4 is now a stale comment - we no longer push the command to a new line if it grows too long.