re PR libstdc++/49060 (use of deleted memory in __gnu_cxx::hashtable::erase)

	PR libstdc++/49060
	* include/backward/hashtable.h (hashtable::erase): Don't crash if
	erasing first and another element with a reference to the other
	element.
	* testsuite/backward/hash_set/49060.cc: New.

From-SVN: r174240

1 files changed, 35 insertions, 0 deletions

diff --git a/libstdc++-v3/testsuite/backward/hash_set/49060.cc b/libstdc++-v3/testsuite/backward/hash_set/49060.cc
new file mode 100644
index 0000000..985cfcf
--- /dev/null
+++ b/libstdc++-v3/testsuite/backward/hash_set/49060.cc
@@ -0,0 +1,35 @@
+// { dg-options "-Wno-deprecated" }
+
+#include <backward/hashtable.h>
+#include <utility>
+
+struct modulo2_hash
+{
+  size_t operator()(int const key) const
+  {
+    return key % 2;
+  }
+};
+
+struct modulo2_eq
+{
+  bool operator()(int const left, int const right) const
+  {
+    return left % 2 == right % 2;
+  }
+};
+
+int main()
+{
+  typedef std::_Select1st<std::pair<int const, int> > extract_type;
+  typedef
+    __gnu_cxx::hashtable<std::pair<int const, int>, int, modulo2_hash,
+			 extract_type, modulo2_eq, std::allocator<int> >
+      table_type;
+  table_type table(4, modulo2_hash(), modulo2_eq(), extract_type(),
+		   std::allocator<int>());
+
+  table.insert_equal(std::make_pair(2, 1));
+  table_type::iterator it(table.insert_equal(std::make_pair(4, 2)));
+  table.erase(it->first);
+}