Preserve sign of -0.0 when result is run through marshal.

diff --git a/Python/compile.c b/Python/compile.c
index 6e68d0fd5da6cee5ab4134c7acc9bc0d293a19aa..71e90f7e21d5eabc8b75ccc29638ed30c0faec86 100644 (file)
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -545,7 +545,7 @@ fold_binops_on_constants(unsigned char *codestr, PyObject *consts)
 static int
 fold_unaryops_on_constants(unsigned char *codestr, PyObject *consts)
 {
-       PyObject *newconst, *v;
+       PyObject *newconst=NULL, *v;
        int len_consts, opcode;
 
        /* Pre-conditions */
@@ -557,7 +557,9 @@ fold_unaryops_on_constants(unsigned char *codestr, PyObject *consts)
        opcode = codestr[3];
        switch (opcode) {
        case UNARY_NEGATIVE:
-               newconst = PyNumber_Negative(v);
+               /* Preserve the sign of -0.0 */
+               if (PyObject_IsTrue(v) == 1)
+                       newconst = PyNumber_Negative(v);
                break;
        case UNARY_CONVERT:
                newconst = PyObject_Repr(v);