[PATCH 2 of 6] parsers.c: parse_index: use named labels and DECREF instead of a generic quit

[Nicolas Dumazet]

# HG changeset patch
# User Nicolas Dumazet <nicdumz.commits at gmail.com>
# Date 1251369670 -7200
# Node ID a235d3e45140f5532b3e7886f7beada51675bde4
# Parent  fdd0c8cdca78d000e76e895519abde0eeb0bbad1
parsers.c: parse_index: use named labels and DECREF instead of a generic quit

This way, we call DECREF only we we _know_ that its refcount has to be
decremented. We also understand that rval never needs to de DECREF'ed:
it's either NULL, either the correct, returned value.

diff --git a/mercurial/parsers.c b/mercurial/parsers.c
--- a/mercurial/parsers.c
+++ b/mercurial/parsers.c
@@ -384,11 +384,11 @@
 	 * plus one for the nullid */
 	index = inlined ? PyList_New(0) : PyList_New(size / 64 + 1);
 	if (!index)
-		goto quit;
+		return NULL;
 
 	nodemap = PyDict_New();
 	if (!nodemap)
-		goto quit;
+		goto err_nonodemap;
 
 	/* set up the cache return value */
 	if (inlined) {
@@ -396,7 +396,7 @@
 		data_obj = PyTuple_GET_ITEM(args, 0);
 		cache = Py_BuildValue("iO", 0, data_obj);
 		if (!cache)
-			goto quit;
+			goto err_nocache;
 	} else {
 		cache = Py_None;
 		Py_INCREF(Py_None);
@@ -412,10 +412,11 @@
 	return rval;
 
 quit:
-	Py_XDECREF(index);
-	Py_XDECREF(nodemap);
-	Py_XDECREF(cache);
-	Py_XDECREF(rval);
+	Py_DECREF(cache);
+err_nocache:
+	Py_DECREF(nodemap);
+err_nonodemap:
+	Py_DECREF(index);
 	return NULL;
 }