[gold patch] Fix usage of invalidated version string in Symbol_table::define_special_symbol

[Viktor Kutuzov <vkutuzov at accesssoftek dot com>]

Hi Ian,

I found that the Symbol_table::define_special_symbol method can return a
pointer to an invalidated version string from the local std::string
object (v) in case of condition only_if_ref == true. This patch should
fix this problem.

-Viktor.

	* symtab.cc (Symbol_table::define_special_symbol): Fix usage of
	the invalidated version string.

Index: symtab.cc
===================================================================
RCS file: /cvs/src/src/gold/symtab.cc,v
retrieving revision 1.159
diff -u -r1.159 symtab.cc
--- symtab.cc	1 Aug 2011 18:25:21 -0000	1.159
+++ symtab.cc	16 Sep 2011 20:35:16 -0000
@@ -1656,13 +1656,9 @@
       bool is_global;
       if (this->version_script_.get_symbol_version(*pname, &v, &is_global))
 	{
-	  if (is_global && !v.empty())
-	    {
-	      *pversion = v.c_str();
-	      // If we get the version from a version script, then we
-	      // are also the default version.
-	      is_default_version = true;
-	    }
+	  // If we get the version from a version script, then we
+	  // are also the default version.
+	  is_default_version = (is_global && !v.empty());
 	}
     }
 
@@ -1676,15 +1672,23 @@
 
   if (only_if_ref)
     {
+      // Look up for the externaly specified or default (NULL) versions.
       oldsym = this->lookup(*pname, *pversion);
+      // Look up for the script specified default version.
       if (oldsym == NULL && is_default_version)
-	oldsym = this->lookup(*pname, NULL);
+	oldsym = this->lookup(*pname, v.c_str());
       if (oldsym == NULL || !oldsym->is_undefined())
 	return NULL;
 
       *pname = oldsym->name();
       if (!is_default_version)
 	*pversion = oldsym->version();
+      
+      if (is_default_version)
+	{
+	  Stringpool::Key version_key = 0;
+	  *pversion = this->namepool_.add(v.c_str(), true, &version_key);
+	}
     }
   else
     {
@@ -1695,6 +1699,8 @@
       Stringpool::Key version_key = 0;
       if (*pversion != NULL)
 	*pversion = this->namepool_.add(*pversion, true, &version_key);
+      else if (is_default_version)
+	*pversion = this->namepool_.add(v.c_str(), true, &version_key);
 
       Symbol* const snull = NULL;
       std::pair<typename Symbol_table_type::iterator, bool> ins =