sprintf format string f is locale dependent, should use F instead
I think this call is an error: calling sprintf("%.5f") here in Italy will result in something like 0,00001 (using comma as a decimal separator) while I think this function should always return a string that remains parsable by php as a float, and so it should always use the dot . as a decimal separator.
Changing f to F will use a NON locale aware conversion, so that the output will always be like 0.00001 (using the dot as a decimal separator) which will always be converted correctly to a float when needed.
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