E.g. the result of apr_snprintf(buf, sizeof(buf), "%.2f", 0.00000001) is "0.0000000" instead of "0.00".
Created attachment 11860 [details] Possible solution.
Created attachment 11861 [details] Testcase
Your patch was just committed to 0.9 and 1.0 branches of APR, along with a test function integrated into APR regression tests. Thanks for the report/fix!