package name is used always from the first element

[alfredbez]

Describe the bug
The package name is always fetched from the first element in the json file as you can see here:

gitlab-composer-repository/src/RegistryBuilder.php

Lines 266 to 273 in 0c1a99a

	function get_package_name($composerData) {
	$data = reset($composerData);
	if (!isset($data['name'])) {
	return false;
	}
	return strtolower($data['name']);
	}

In our case, there was a package with two branches which had another name in the composer.json and we were not able to install the package by the name provided in the composer.json on the develop branch.

composer.json on broken branch:

    "name": "vendorFoo/barWrong",

composer.json on develop branch:

    "name": "vendorFoo/barRight",

The resulting packages.json file showed only vendorFoo/barWrong, but not vendorFoo/barRight.

To Reproduce

1. Create a new project with a composer.json, using vendorfoo/bar as the name
2. Commit and push the code
3. Create a new branch and change the name of the package in the composer.json to vendorbaz/bar. I'm not sure how to force the new branch to be on top of the other available branches and tags (alphabetical order?)
4. Remove the cached json files on your server
5. Regenerate the packages.json file
6. Take a look into that file and check the name of the package, only one package should be available (either vendorfoo/bar or vendorbaz/bar)

Expected behavior
I expected to be able to install both packages.

[keywan-ghadami-oxid]

should be fixed on master branch, it collects now all names from all branches.