"Show Project-level variable details" API call returns only one result for multiple variables with the same name

Hello. I checked twice and haven't found any related issue.

Summary

I run into a problem with using v4 api to get Project-level variable details. This call returns only one result in case of many project variables with the same name, but with different environment_scope parameters.

Method documentation https://docs.gitlab.com/ee/api/project_level_variables.html#show-variable-details

Steps to reproduce

• Add multiple project variables with the same name, but with different environment_scope parameters.
• Get access token and request variable details

curl -sH "PRIVATE-TOKEN: ${GITLAB_TOKEN}" "https://gitlab.com/api/v4/projects/13745804/variables/TEST_VAR"|jq .
{
  "variable_type": "env_var",
  "key": "TEST_VAR",
  "value": "ddd",
  "protected": false,
  "masked": false,
  "environment_scope": "*"
}

• only one result returned
• But there are more variables with the same name

curl -sH "PRIVATE-TOKEN: ${GITLAB_TOKEN}" "https://gitlab.com/api/v4/projects/13745804/variables"|jq .
[
  {
    "variable_type": "env_var",
    "key": "TEST_VAR",
    "value": "123",
    "protected": false,
    "masked": false,
    "environment_scope": "env1"
  },
  {
    "variable_type": "env_var",
    "key": "TEST_VAR",
    "value": "321",
    "protected": false,
    "masked": false,
    "environment_scope": "env2"
  },
  {
    "variable_type": "env_var",
    "key": "TEST_VAR",
    "value": "456",
    "protected": false,
    "masked": false,
    "environment_scope": "env3"
  },
  {
    "variable_type": "env_var",
    "key": "TEST_VAR",
    "value": "ddd",
    "protected": false,
    "masked": false,
    "environment_scope": "*"
  }
]

Example Project

https://gitlab.com/Nklya/test-api

What is the current bug behavior?

Only one variable details returned

What is the expected correct behavior?

All environment variables with the same name return

Relevant logs and/or screenshots

My example project variables

Output of checks

This bug happens on GitLab.com too

Results of GitLab environment info

Tested on GitLab.com and private GitLab Enterprise Edition 11.11

Results of GitLab application Check

Not applicable, as bug reproduced on GitLab.com

Possible fixes

For now, I found a workaround with requesting all variables with https://docs.gitlab.com/ce/api/project_level_variables.html#list-project-variables and then check all of them.