Fix broken map::operator[].

    According to the STL documentation, 'insert' should do nothing if
    attempting to insert an item that already exists.  This allows []
    to be implemented as a form of insert(pair(key, data_T())).  Our
    insert was actually updating the data portion of the map, which
    was causing operator[] to always erase the data portion of any
    lookup.

Change-Id: I5b2ae1934dbd81d71df4b56d83e2f04f53f0e525
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/825
Tested-by: Jenkins Server
Reviewed-by: Douglas R. Gilbert <dgilbert@us.ibm.com>
Reviewed-by: Bradley W. Bishop <bradleyb@us.ibm.com>
Reviewed-by: A. Patrick Williams III <iawillia@us.ibm.com>

2 files changed, 6 insertions, 1 deletions

diff --git a/src/include/util/impl/stlmap.H b/src/include/util/impl/stlmap.H
index bed6674b7..599e1ed22 100644
--- a/src/include/util/impl/stlmap.H
+++ b/src/include/util/impl/stlmap.H
@@ -340,7 +340,6 @@ namespace Util
                     }
                     else
                     {
-                        reinterpret_cast<_Node*>(n)->data_T().second = x.second;
                         return make_pair(iterator(_TreeItr(&iv_tree, n)),
                                                   true);
                     }
diff --git a/src/usr/testcore/lib/stltest.H b/src/usr/testcore/lib/stltest.H
index b9a16d927..2c4efcb14 100644
--- a/src/usr/testcore/lib/stltest.H
+++ b/src/usr/testcore/lib/stltest.H
@@ -85,6 +85,12 @@ class STLTest : public CxxTest::TestSuite
             mymap[v5] = v5;
             mymap[v3] = v3;
 
+            if (v5.value() != mymap[v5].value())   // map::operator[] value
+            {
+                TS_FAIL("map::operator[] returned wrong value %d",
+                        mymap[v5].value());
+            }
+
             // test map::insert(v), map::insert(h,v), lower_bound()
             mymap.insert(std::map<V,V>::value_type(v2,v2));  //map::insert(v);