Description:
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Given an array without index, http_build_query() adds numeric index 0, 1, 2,... in its output. This is working if the web server is php, but fails to work when I use php curl functions to send the array to a rails server. Rails server treats this as a hash (with the added index in http_build_query() output).

Test script:
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<?php

echo http_build_query(['user_ids' => [1313346,1313342,1313345]]);
// output:
//      user_ids%5B0%5D=1313346&user_ids%5B1%5D=1313342&user_ids%5B2%5D=1313345


Expected result:
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user_ids%5B%5D=1313346&user_ids%5B%5D=1313342&user_ids%5B%5D=1313345

Actual result:
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user_ids%5B0%5D=1313346&user_ids%5B1%5D=1313342&user_ids%5B2%5D=1313345