re PR libstdc++/14220 ([3.5] num_put::do_put() undesired float/double behavior)

2004-02-22  Paolo Carlini  <pcarlini@suse.de>

	PR libstdc++/14220
	* include/bits/locale_facets.tcc (num_put<>::_M_convert_float):
	Don't clip the precision passed down to __convert_from_v:
	22.2.2.2.2 nowhere says so.

From-SVN: r78268

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 03f66fa5e690c8c60b98b823c7febc0097cf1a9a..2bb5a2a2d919f23fb1627fe8788077f659b3db94 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,10 @@
+2004-02-22  Paolo Carlini  <pcarlini@suse.de>
+
+       PR libstdc++/14220
+       * include/bits/locale_facets.tcc (num_put<>::_M_convert_float):
+       Don't clip the precision passed down to __convert_from_v:
+       22.2.2.2.2 nowhere says so.
+
 2004-02-14  Release Manager
 
        * GCC 3.3.3 Released.

diff --git a/libstdc++-v3/include/bits/locale_facets.tcc b/libstdc++-v3/include/bits/locale_facets.tcc
index 3dec34ecdaa3f48e3d4378375f5997adc37bae5c..641d333fa8a732e74d659e5d2a620b1d4e98851b 100644 (file)
--- a/libstdc++-v3/include/bits/locale_facets.tcc
+++ b/libstdc++-v3/include/bits/locale_facets.tcc
@@ -884,22 +884,13 @@ namespace std
       _M_convert_float(_OutIter __s, ios_base& __io, _CharT __fill, char __mod,
                       _ValueT __v) const
       {
-       // Note: digits10 is rounded down: add 1 to ensure the maximum
-       // available precision.  Then, in general, one more 1 needs to
-       // be added since, when the %{g,G} conversion specifiers are
-       // chosen inside _S_format_float, the precision field is "the
-       // maximum number of significant digits", *not* the "number of
-       // digits to appear after the decimal point", as happens for
-       // %{e,E,f,F} (C99, 7.19.6.1,4).
-       const int __max_digits = numeric_limits<_ValueT>::digits10 + 2;
-
        // Use default precision if out of range.
        streamsize __prec = __io.precision();
-       if (__prec > static_cast<streamsize>(__max_digits))
-         __prec = static_cast<streamsize>(__max_digits);
-       else if (__prec < static_cast<streamsize>(0))
+       if (__prec < static_cast<streamsize>(0))
          __prec = static_cast<streamsize>(6);
 
+       const int __max_digits = numeric_limits<_ValueT>::digits10;     
+
        typedef numpunct<_CharT>  __facet_type;
        typedef __locale_cache<numpunct<_CharT> > __cache_type;
        const locale __loc = __io._M_getloc();
@@ -911,7 +902,7 @@ namespace std
        char __fbuf[16];
 
 #ifdef _GLIBCPP_USE_C99
-       // First try a buffer perhaps big enough (for sure sufficient
+       // First try a buffer perhaps big enough (most probably sufficient
        // for non-ios_base::fixed outputs)
        int __cs_size = __max_digits * 3;
        char* __cs = static_cast<char*>(__builtin_alloca(__cs_size));
@@ -933,13 +924,13 @@ namespace std
        const bool __fixed = __io.flags() & ios_base::fixed;
        const int __max_exp = numeric_limits<_ValueT>::max_exponent10;
 
-       // ios_base::fixed outputs may need up to __max_exp+1 chars
-       // for the integer part + up to __max_digits chars for the
-       // fractional part + 3 chars for sign, decimal point, '\0'. On
-       // the other hand, for non-fixed outputs __max_digits*3 chars
-       // are largely sufficient.
-       const int __cs_size = __fixed ? __max_exp + __max_digits + 4 
-                                     : __max_digits * 3;
+       // ios_base::fixed outputs may need up to __max_exp + 1 chars
+       // for the integer part + __prec chars for the fractional part
+       // + 3 chars for sign, decimal point, '\0'. On the other hand,
+       // for non-fixed outputs __max_digits * 2 chars + __prec are
+       // largely sufficient.
+       const int __cs_size = __fixed ? __max_exp + __prec + 4 
+                                     : __max_digits * 2 + __prec;
        char* __cs = static_cast<char*>(__builtin_alloca(__cs_size));
 
        _S_format_float(__io, __fbuf, __mod, __prec);