tags 27407 + patch
severity 27407 minor
quit

Pierre Neidhardt <ambrevar@gmail.com> writes:

> Steps to reproduce:
>
> - M-x eshell
> - Enter "hello"
>
> The new prompt becomes yellow.

You meant enter the text produced with (insert "echo \"\e[33mhello\e[0m\"").

> It does not happen if the SGR reset sequence is not last.
> This is fine for instance:
>
> - echo "hello"X
> - echo -n "hello"
>
> Maybe an off-by-one error in the `ansi-*' function?

The escape code is implemented by applying an overlay to the text
following it (see `ansi-color-apply-on-region').  The problem seems to
be that the reset sequence is translated to no face, so nothing is
applied (see `ansi-color-apply-overlay-face'), and the yellow overlay
gets extended despite the `ansi-color-freeze-overlay' modification-hook
because `eshell-output-filter' (and `eshell-send-input') let-bind
`inhibit-modification-hooks'.

I'm not sure why `inhibit-modification-hooks' needs to be let-bound at
all, but just binding it to nil around string insertion seems to be
enough: