[Patch] More redundant NULL pointer checks

[Paolo Carlini <pcarlini at unitus dot it>]

Hi,

the below, which I consider almost obvious in the light of
the good acceptance of the previous one, completes the work
for stringstreams. Some constification in this case too.

Will wait one day, then commit.

Paolo.

//////////
2003-04-19  Paolo Carlini  <pcarlini at unitus dot it>

	* include/bits/sstream.tcc (pbackfail): Remove redundant
	NULL pointer check from test involving _M_in_*.
	(overflow, seekoff, seekpos): Const qualify bool variables.
	* include/std/std_sstream.h (underflow): Remove redundant
	NULL pointer check from test involving _M_in_*.
	(_M_really_sync): Const qualify bool variables.

	* include/std/std_streambuf.h (sgetc): Remove redundant
	variable.

diff -urN libstdc++-v3-orig/include/bits/sstream.tcc libstdc++-v3/include/bits/sstream.tcc
--- libstdc++-v3-orig/include/bits/sstream.tcc	2003-04-12 21:21:34.000000000 +0200
+++ libstdc++-v3/include/bits/sstream.tcc	2003-04-19 18:40:17.000000000 +0200
@@ -47,8 +47,9 @@
     pbackfail(int_type __c)
     {
       int_type __ret = traits_type::eof();
-      bool __testeof = traits_type::eq_int_type(__c, traits_type::eof());
-      bool __testpos = this->_M_in_cur && this->_M_in_beg < this->_M_in_cur; 
+      const bool __testeof = 
+	traits_type::eq_int_type(__c, traits_type::eof());
+      const bool __testpos = this->_M_in_beg < this->_M_in_cur; 
       
       // Try to put back __c into input sequence in one of three ways.
       // Order these tests done in is unspecified by the standard.
@@ -80,11 +81,12 @@
     basic_stringbuf<_CharT, _Traits, _Alloc>::
     overflow(int_type __c)
     {
-      bool __testout = this->_M_mode & ios_base::out;
+      const bool __testout = this->_M_mode & ios_base::out;
       if (__builtin_expect(!__testout, false))
 	return traits_type::eof();
 
-      bool __testeof = traits_type::eq_int_type(__c, traits_type::eof());
+      const bool __testeof =
+	traits_type::eq_int_type(__c, traits_type::eof());
       if (__builtin_expect(__testeof, false))
 	return traits_type::not_eof(__c);
 
@@ -94,7 +96,7 @@
       // suit particular needs.
       __size_type __len = std::max(__size_type(_M_string.capacity() + 1),
 				   __size_type(512));
-      bool __testput = this->_M_out_cur < this->_M_out_end;
+      const bool __testput = this->_M_out_cur < this->_M_out_end;
       if (__builtin_expect(!__testput && __len > _M_string.max_size(), false))
 	return traits_type::eof();
 
@@ -123,7 +125,7 @@
       pos_type __ret =  pos_type(off_type(-1)); 
       bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
       bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
-      bool __testboth = __testin && __testout && __way != ios_base::cur;
+      const bool __testboth = __testin && __testout && __way != ios_base::cur;
       __testin &= !(__mode & ios_base::out);
       __testout &= !(__mode & ios_base::in);
 
@@ -189,8 +191,8 @@
 	  off_type __pos = __sp; // Use streamoff operator to do conversion.
 	  char_type* __beg = NULL;
 	  char_type* __end = NULL;
-	  bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
-	  bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
+	  const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
+	  const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
 	  
 	  // NB: Ordered.
 	  bool __testposi = false;
diff -urN libstdc++-v3-orig/include/std/std_sstream.h libstdc++-v3/include/std/std_sstream.h
--- libstdc++-v3-orig/include/std/std_sstream.h	2003-04-12 21:21:34.000000000 +0200
+++ libstdc++-v3/include/std/std_sstream.h	2003-04-19 18:10:45.000000000 +0200
@@ -190,7 +190,7 @@
       virtual int_type
       underflow()
       {
-	if (this->_M_in_cur && this->_M_in_cur < this->_M_in_end)
+	if (this->_M_in_cur < this->_M_in_end)
 	  return traits_type::to_int_type(*gptr());
 	else
 	  return traits_type::eof();
@@ -260,8 +260,8 @@
       virtual void
       _M_really_sync(char_type* __base, __size_type __i, __size_type __o)
       {
-	bool __testin = this->_M_mode & ios_base::in;
-	bool __testout = this->_M_mode & ios_base::out;
+	const bool __testin = this->_M_mode & ios_base::in;
+	const bool __testout = this->_M_mode & ios_base::out;
 	__size_type __len = _M_string.size();
 
 	this->_M_buf = __base;
diff -urN libstdc++-v3-orig/include/std/std_streambuf.h libstdc++-v3/include/std/std_streambuf.h
--- libstdc++-v3-orig/include/std/std_streambuf.h	2003-04-19 13:28:45.000000000 +0200
+++ libstdc++-v3/include/std/std_streambuf.h	2003-04-19 18:23:25.000000000 +0200
@@ -452,12 +452,10 @@
       int_type 
       sgetc()
       {
-	int_type __ret;
 	if (_M_in_cur < _M_in_end)
-	  __ret = traits_type::to_int_type(*(this->gptr()));
+	  return traits_type::to_int_type(*(this->gptr()));
 	else 
-	  __ret = this->underflow();
-	return __ret;
+	  return this->underflow();
       }
 
       /**