[google] Handle NULL return values in setlocale calls (issue4444046)

[Diego Novillo]

I'm committing this patch for Jing Yu on google/main.

The patch handles NULL values returned from setlocale.  Jing, could
you please describe why this was needed?  Is this a patch that you
will want to submit for trunk?

Tested on x86_64.  Committed to google/main.


Diego.

2011-04-15  Jing Yu  <jingyu@google.com>
    
	Google ref 46499.

    	* config/locale/generic/c_locale.cc (__convert_to_v): Handle
    	NULL return value from setlocale.
    	* config/locale/generic/c_locale.h (__convert_from_v): Likewise.
    	* config/locale/generic/time_members.cc (_M_put): Likewise.

diff --git a/libstdc++-v3/config/locale/generic/c_locale.cc b/libstdc++-v3/config/locale/generic/c_locale.cc
index fb9b425..7e34fcf 100644
--- a/libstdc++-v3/config/locale/generic/c_locale.cc
+++ b/libstdc++-v3/config/locale/generic/c_locale.cc
@@ -52,10 +52,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       // Assumes __s formatted for "C" locale.
       char* __old = setlocale(LC_ALL, 0);
-      const size_t __len = strlen(__old) + 1;
-      char* __sav = new char[__len];
-      memcpy(__sav, __old, __len);
-      setlocale(LC_ALL, "C");
+      char* __sav = NULL;
+      if (__old != NULL)
+        {
+          const size_t __len = strlen(__old) + 1;
+          __sav = new char[__len];
+          memcpy(__sav, __old, __len);
+          setlocale(LC_ALL, "C");
+        }
       char* __sanity;
       bool __overflow = false;
 
@@ -117,10 +121,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       // Assumes __s formatted for "C" locale.
       char* __old = setlocale(LC_ALL, 0);
-      const size_t __len = strlen(__old) + 1;
-      char* __sav = new char[__len];
-      memcpy(__sav, __old, __len);
-      setlocale(LC_ALL, "C");
+      char* __sav = NULL;
+      if (__old != NULL)
+        {
+          const size_t __len = strlen(__old) + 1;
+          __sav = new char[__len];
+          memcpy(__sav, __old, __len);
+          setlocale(LC_ALL, "C");
+        }
       char* __sanity;
 
 #if !__DBL_HAS_INFINITY__
@@ -162,10 +170,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       // Assumes __s formatted for "C" locale.
       char* __old = setlocale(LC_ALL, 0);
-      const size_t __len = strlen(__old) + 1;
-      char* __sav = new char[__len];
-      memcpy(__sav, __old, __len);
-      setlocale(LC_ALL, "C");
+      char* __sav = NULL;
+      if (__old != NULL)
+        {
+          const size_t __len = strlen(__old) + 1;
+          __sav = new char[__len];
+          memcpy(__sav, __old, __len);
+          setlocale(LC_ALL, "C");
+        }
 
 #if !__LDBL_HAS_INFINITY__
       errno = 0;
diff --git a/libstdc++-v3/config/locale/generic/c_locale.h b/libstdc++-v3/config/locale/generic/c_locale.h
index 2c76000..6e6f673 100644
--- a/libstdc++-v3/config/locale/generic/c_locale.h
+++ b/libstdc++-v3/config/locale/generic/c_locale.h
@@ -60,7 +60,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   {
     char* __old = std::setlocale(LC_NUMERIC, 0);
     char* __sav = 0;
-    if (__builtin_strcmp(__old, "C"))
+    if (__old != NULL && __builtin_strcmp(__old, "C"))
       {
 	const size_t __len = __builtin_strlen(__old) + 1;
 	__sav = new char[__len];
diff --git a/libstdc++-v3/config/locale/generic/time_members.cc b/libstdc++-v3/config/locale/generic/time_members.cc
index 3031075..fb9eb6e 100644
--- a/libstdc++-v3/config/locale/generic/time_members.cc
+++ b/libstdc++-v3/config/locale/generic/time_members.cc
@@ -45,10 +45,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	   const tm* __tm) const throw()
     {
       char* __old = setlocale(LC_ALL, 0);
-      const size_t __llen = strlen(__old) + 1;
-      char* __sav = new char[__llen];
-      memcpy(__sav, __old, __llen);
-      setlocale(LC_ALL, _M_name_timepunct);
+      char* __sav = NULL;
+      if (__old != NULL)
+        {
+          const size_t __llen = strlen(__old) + 1;
+          __sav = new char[__llen];
+          memcpy(__sav, __old, __llen);
+          setlocale(LC_ALL, _M_name_timepunct);
+        }
       const size_t __len = strftime(__s, __maxlen, __format, __tm);
       setlocale(LC_ALL, __sav);
       delete [] __sav;
@@ -130,10 +134,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	   const tm* __tm) const throw()
     {
       char* __old = setlocale(LC_ALL, 0);
-      const size_t __llen = strlen(__old) + 1;
-      char* __sav = new char[__llen];
-      memcpy(__sav, __old, __llen);
-      setlocale(LC_ALL, _M_name_timepunct);
+      char* __sav = NULL;
+      if (__old != NULL)
+        {
+          const size_t __llen = strlen(__old) + 1;
+          __sav = new char[__llen];
+          memcpy(__sav, __old, __llen);
+          setlocale(LC_ALL, _M_name_timepunct);
+        }
       const size_t __len = wcsftime(__s, __maxlen, __format, __tm);
       setlocale(LC_ALL, __sav);
       delete [] __sav;


--
This patch is available for review at http://codereview.appspot.com/4444046