This is a small fix for default values in task variables. The
[documentation](https://zed.dev/docs/tasks) states
> You can also use verbose syntax that allows specifying a default if a
given variable is not available: ${ZED_FILE:default_value}
I found, however, that this doesn't actually work. Instead, the Zed
variable and the default value are just appended in the output. For
example, if I run a task `echo ${ZED_ROW:100}` the result I get is
`447:100` (in this case it should just be `447`).
This PR fixes that. I also added a new test case for handling default
values.
I also tested the fix in a dev build and it seems to work.
There are no UI adjustments.
AI disclosure: I used Claude Code to write the code, including the fix
and the tests.
This is actually my first open-source PR ever, so if I did something
wrong, I'd appreciate any tips and I'll make it right!
Release Notes:
- Fixed task variable substitution always appending the default
74e8afe9a8