Both depends_on and ignore_changes contain references to objects that we
can validate.
Historically Terraform has not validated these, instead just ignoring
references to non-existent objects. Since there is no reason to refer to
something that doesn't exist, we'll now verify this and return errors so
that users get explicit feedback on any typos they may have made, rather
than just wondering why what they added seems to have no effect.
This is particularly important for ignore_changes because users have
historically used strange values here to try to exploit the fact that
Terraform was resolving ignore_changes against a flatmap. This will give
them explicit feedback for any odd constructs that the configuration
upgrade tool doesn't know how to detect and fix.
This includes a fix to hcl.RelTraversalForExpr where it would
inadvertantly modify the internals of a traversal AST node as part of
relativizing the traversal in order to return it.
This includes a number of upstream bug fixes, which in turn fix a number
of issues here in Terraform:
- New-style "full splat" operator now working correctly (#19181)
- The weird HCL1-ish single-line block syntax is now supported (#19153)
- Formatting of single-line blocks adds spaces around the braces (#19154)
This also includes a number of other upstream fixes that were not tracked
as issues in the Terraform repository. The highlights of those are:
- A for expression with the "for" keyword wrapped onto a newline after its
opening bracket now parses correctly.
- In JSON syntax, interpolation sequences in properties of objects that
are representing expressions now have their variables properly detected.
- The "flush" heredoc variant is now functional again after being broken
in some (much-)earlier rework of the template parser.
Notable changes:
* backend/s3: Automatic validation of `eu-north-1` region
* backend/s3: Support for `credential_process` handling in AWS configuration file
Updated via:
```
go get github.com/aws/aws-sdk-go@v1.16.4
go get github.com/terraform-providers/terraform-provider-aws@v1.52.0
go mod tidy
go mod vendor
```
James Bardin