bpo-32436: Fix a refleak; var GC tracking; a GCC warning (#5326)

The refleak in question wasn't really important, as context vars
are usually created at the toplevel and live as long as the interpreter
lives, so the context var name isn't ever GCed anyways.

2 files changed, 6 insertions, 4 deletions

diff --git a/Python/context.c b/Python/context.c
index 5439531cd1..d90ed25c4d 100644
--- a/Python/context.c
+++ b/Python/context.c
@@ -134,7 +134,9 @@ PyContextVar_New(const char *name, PyObject *def)
     if (pyname == NULL) {
         return NULL;
     }
-    return contextvar_new(pyname, def);
+    PyContextVar *var = contextvar_new(pyname, def);
+    Py_DECREF(pyname);
+    return var;
 }
 
 
@@ -741,8 +743,8 @@ contextvar_new(PyObject *name, PyObject *def)
     var->var_cached_tsid = 0;
     var->var_cached_tsver = 0;
 
-    if (_PyObject_GC_IS_TRACKED(name) ||
-            (def != NULL && _PyObject_GC_IS_TRACKED(def)))
+    if (_PyObject_GC_MAY_BE_TRACKED(name) ||
+            (def != NULL && _PyObject_GC_MAY_BE_TRACKED(def)))
     {
         PyObject_GC_Track(var);
     }
diff --git a/Python/hamt.c b/Python/hamt.c
index df3b1092cb..79c42c0f43 100644
--- a/Python/hamt.c
+++ b/Python/hamt.c
@@ -449,7 +449,7 @@ hamt_bitcount(uint32_t i)
     */
     i = i - ((i >> 1) & 0x55555555);
     i = (i & 0x33333333) + ((i >> 2) & 0x33333333);
-    return ((i + (i >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;
+    return (((i + (i >> 4)) & 0xF0F0F0F) * 0x1010101) >> 24;
 }
 
 static inline uint32_t