s2f() and s2d() fail with trailing decimal zeros

[biojppm]

It is easy to reproduce this in the unit tests:

// s2f_test.cc
TEST(S2fTest, TrailingDecimalZeros) {
  EXPECT_S2F(1.f, "1");
  EXPECT_S2F(1.f, "1.000");
  EXPECT_S2F(1.f, "1.000000000");  // fail: INPUT_TOO_LONG
  EXPECT_S2F(8388605.f, "8388605");
  EXPECT_S2F(8388605.f, "8388605.00");
  EXPECT_S2F(8388605.f, "8388605.000"); // fail: INPUT_TOO_LONG
}

// s2d_test.cc
TEST(S2dTest, TrailingDecimalZeros) {
  EXPECT_S2D(1.      , "1");
  EXPECT_S2D(1.      , "1.000");
  EXPECT_S2D(1.      , "1.0000000000000000");
  EXPECT_S2D(1.      , "1.00000000000000000"); // fail: INPUT_TOO_LONG
  EXPECT_S2D(8388605., "8388605");
  EXPECT_S2D(8388605., "8388605.000");
  EXPECT_S2D(8388605., "8388605.0000000000");
  EXPECT_S2D(8388605., "8388605.00000000000"); // fail: INPUT_TOO_LONG
}