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Unlike other shells, fish tries to make it easy to work with multiline commands. Arguably, it's often better to use a full text editor but the shell can feel more convenient. Spreading long commands into multiple lines can improve readability, especially when there is some semantic grouping (loops, pipelines, command substitutions, quoted parts). Note that in Unix shell, every quoted string can span multiple lines, like Python's triple quotes, so the barrier to writing a multiline command is quite low. However these commands are not autosuggested. From1c4e5cadf2 (commitcomment-150853293)> the reason we don't offer multi-line autosuggestion is that they > can cause the command line to "jump" to make room for the second > and third lines, if you're at the bottom of your terminal. This jumping (as done by nushell for example) might be surprising, especially since there is no limit on the height of a command. Let's maybe avoid this jumping by rendering only however many lines from the autosuggestion can fit on the screen without scrolling. The truncation is hinted at by a single ellipsis ("…") after the last suggested character, just like when a single-line autosuggestion is truncated. (We might want to use something else in future.) To implement this, query for the cursor position after every command, so we know the y-position of the shell prompt within the terminal window (whose height we already know). Also, after we register a terminal window resize, query for the cursor position before doing anything else (until we od #12004, only height changes are relevant), to prevent this scenario: 1. move prompt to bottom of terminal 2. reduce terminal height 3. increase terminal height 4. type a command that triggers a multi-line autosuggestion 5. observe that it would fail to truncate properly As a refresher: when we fail to receive a query response, we always wait for 2 seconds, except if the initial query had also failed, seeb907bc775a(Use a low TTY query timeout only if first query failed, 2025-09-25). If the terminal does not support cursor position report (which is unlikely), show at most 1 line worth of autosuggestion. Note that either way, we don't skip multiline commands anymore. This might make the behavior worse on such terminals, which are probably not important enough. Alternatively, we could use no limit for such terminals, that's probably the better fallback behavior. The only reason I didn't do that yet is to stay a little bit closer to historical behavior. Storing the prompt's position simplifies scrollback-push and the mouse click handler, which no longer need to query. Move some associated code to the screen module. Technically we don't need to query for cursor position if the previous command was empty. But for now we do, trading a potential optimization for andother simplification. Disable this feature in pexpect tests for now, since those are still missing some terminal emulation features.