diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 3e4eb3e1682..34b1304af06 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,10 @@
+2002-04-26  Paolo Carlini  <pcarlini@unitus.it>
+
+	* include/bits/basic_string.h (replace(__pos, __n1, __s, __n2):
+	Fix and tighten __throw_length_error check.
+	* testsuite/21_strings/replace.cc (test05): New.
+	* testsuite/21_strings/replace.cc (test02, test03, test04): Tweak.
+
 2002-04-23  Loren J. Rittle <ljrittle@acm.org>
 
 	* include/std/std_fstream.h (basic_filebuf::sync): Hoist
diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index ab2360f77d9..b7d826dc08b 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -642,10 +642,10 @@ namespace std
 	const size_type __size = this->size();
  	if (__pos > __size)
 	  __throw_out_of_range("basic_string::replace");
-	if (__size - __n1 > this->max_size() - __n2)
-	  __throw_length_error("basic_string::replace");
 	const bool __testn1 = __n1 < __size - __pos;
 	const size_type __foldn1 = __testn1 ? __n1 : __size - __pos;
+	if (__size - __foldn1 > this->max_size() - __n2)
+	  __throw_length_error("basic_string::replace");
 	if (_M_rep()->_M_is_shared() || less<const _CharT*>()(__s, _M_data())
 	    || less<const _CharT*>()(_M_data() + __size, __s))
 	  return _M_replace_safe(_M_ibegin() + __pos,
diff --git a/libstdc++-v3/testsuite/21_strings/replace.cc b/libstdc++-v3/testsuite/21_strings/replace.cc
index 1b3cc3162f2..6dc9ec6b9bf 100644
--- a/libstdc++-v3/testsuite/21_strings/replace.cc
+++ b/libstdc++-v3/testsuite/21_strings/replace.cc
@@ -84,6 +84,7 @@ bool test01(void)
 void
 test02()
 {
+  bool test = true;
   const char* strlit = "../the long pier/Hanalei Bay/Kauai/Hawaii";
   std::string aux = strlit;
   aux.replace(aux.begin()+5, aux.begin()+20,
@@ -100,6 +101,7 @@ test02()
 void
 test03()
 {
+  bool test = true;
   const char* title01 = "nine types of ambiguity";
   const char* title02 = "ultra";
   std::string str01 = title01;
@@ -145,6 +147,7 @@ test03()
 void
 test04()
 {
+  bool test = true;
   std::string str01 = "geogaddi";
   std::string str02;
 
@@ -175,11 +178,25 @@ test04()
   VERIFY(str02 == "geogaddi");
 }
 
+// We wrongly used __n1 instead of __foldn1 in the length_error
+// check at the beginning of replace(__pos, __n1, __s, __n2)
+void
+test05()
+{
+  bool test = true;
+  std::string str01 = "londinium";
+  std::string str02 = "cydonia";
+
+  str01.replace(0, 20, str02.c_str(), 3);
+  VERIFY(str01 == "cyd");
+}
+
 int main()
 { 
   test01();
   test02();
   test03();
   test04();
+  test05();
   return 0;
 }