[Bug]: Empty Tag in Provider's default_tags Clears Previous Tags

[sam-axcient]

Terraform Core Version

1.6.0

AWS Provider Version

5.23.1, 5.23.0

Affected Resource(s)

aws_cloudwatch_log_group

Expected Behavior

Adding an empty tag to the provider's default_tags should be added to all resources

Actual Behavior

Adding an empty tag to the provider's default_tags currently clears all previous tags on resources, and new tags do not update after applying.

Relevant Error/Panic Output Snippet

No response

Terraform Configuration Files

provider "aws" {
  default_tags {
    tags = {
      Service        = "myservice"
      # Owner          = ""
    }
  }
}

resource "aws_cloudwatch_log_group" "api_gw" {
  name              = "/aws/api_gw/some-gateway"
}

output "api_gw_tags_all" {
  value = aws_cloudwatch_log_group.api_gw.tags_all
}

Steps to Reproduce

1. Run terraform apply to set up resources with tags.
2. Now, run terraform apply again with an uncommented empty tag in the default_tags configuration.

Debug Output

first.log
Outputs

api_gw_tags_all = tomap({
  "Service" = "myservice"
})

second.log
Outputs:

api_gw_tags_all = tomap({})

Panic Output

No response

Important Factoids

No response

References

No response

Would you like to implement a fix?

No

[github-actions]

Community Note

Voting for Prioritization

• Please vote on this issue by adding a 👍 reaction to the original post to help the community and maintainers prioritize this request.
• Please see our prioritization guide for information on how we prioritize.
• Please do not leave "+1" or other comments that do not add relevant new information or questions, they generate extra noise for issue followers and do not help prioritize the request.

Volunteering to Work on This Issue

• If you are interested in working on this issue, please leave a comment.
• If this would be your first contribution, please review the contribution guide.

[johnsonaj]

Relates to #31941