vared tmp doesn't set tmp #8836
Description
Fish $version: 3.4.0-53-g3e5284aaf
OS: Arch linux x86_64
Terminal: Sakura 3.8.4
Effected by user config: No
Summary: vared specifically fails to set a variable named tmp. Any other names I have tested work correctly (ie. do set the variable.). 'Emulating' vared via set tmp (read) works correctly.
How to reproduce:
vared tmp; vared tmp2; set -S tmp tmp2
(input some values)
-> tmp is unset, tmp2 is set correctly (global var, unexported).
This is probably tied to the internal use of 'tmp' as a variable name. Changing this name to something more obscure like __vared_user_input seems to fix the problem.
Another facet of the issue is that set $argv is inadequate when the value of argv matches the name of the temporary variable (and the above 'fix' is obviously only a workaround). What vared really wants to do is set the nearest-scoped variable named by $argv that isn't of the same scope as the temporary variable. Not sure if there is actually a way to do that. It might be easier for fish to provide a mktempvar builtin, which could provide a pretty good guarantee that the generated variable name would not collide.