Added more comments to the new structseq repr code and implemented several of Neal...

diff --git a/Objects/structseq.c b/Objects/structseq.c
index 8e27441bace00595a0c01565576c08e7a311acad..b6126bae467e99b038542b1bd1076acc2fd9c65b 100644 (file)
--- a/Objects/structseq.c
+++ b/Objects/structseq.c
@@ -230,23 +230,37 @@ make_tuple(PyStructSequence *obj)
 static PyObject *
 structseq_repr(PyStructSequence *obj)
 {
-       PyObject *tup, *val, *repr;
+       /* buffer and type size were chosen well considered. */
+#define REPR_BUFFER_SIZE 512
+#define TYPE_MAXSIZE 100
+
+       PyObject *tup;
        PyTypeObject *typ = Py_TYPE(obj);
-       int i, len;
-       char buf[250+5]; /* "...)\0" */
-       char *cname, *crepr;
-       char *pbuf = buf;
-       char *endbuf = &buf[250];
-
-       strncpy(pbuf, typ->tp_name, 50);
-       pbuf += strlen(typ->tp_name) > 50 ? 50 : strlen(typ->tp_name);
-       *pbuf++ = '(';
+       int i, removelast = 0;
+       Py_ssize_t len;
+       char buf[REPR_BUFFER_SIZE];
+       char *endofbuf, *pbuf = buf;
+
+       /* pointer to end of writeable buffer; safes space for "...)\0" */
+       endofbuf= &buf[REPR_BUFFER_SIZE-5];
 
        if ((tup = make_tuple(obj)) == NULL) {
                return NULL;
        }
+
+       /* "typename(", limited to  TYPE_MAXSIZE */
+       len = strlen(typ->tp_name) > TYPE_MAXSIZE ? TYPE_MAXSIZE :
+                                                   strlen(typ->tp_name);
+       strncpy(pbuf, typ->tp_name, len);
+       pbuf += len;
+       *pbuf++ = '(';
+
        for (i=0; i < VISIBLE_SIZE(obj); i++) {
+               PyObject *val, *repr;
+               char *cname, *crepr;
+
                cname = typ->tp_members[i].name;
+               
                val = PyTuple_GetItem(tup, i);
                if (cname == NULL || val == NULL) {
                        return NULL;
@@ -262,8 +276,10 @@ structseq_repr(PyStructSequence *obj)
                        Py_DECREF(repr);
                        return NULL;
                }
-               len = strlen(cname) + strlen(crepr) + 3;
-               if ((pbuf+len) < endbuf) {
+               
+               /* + 3: keep space for "=" and ", " */
+               len = strlen(cname) + strlen(crepr) + 3;
+               if ((pbuf+len) <= endofbuf) {
                        strcpy(pbuf, cname);
                        pbuf += strlen(cname);
                        *pbuf++ = '=';
@@ -271,23 +287,26 @@ structseq_repr(PyStructSequence *obj)
                        pbuf += strlen(crepr);
                        *pbuf++ = ',';
                        *pbuf++ = ' ';
+                       removelast = 1;
                        Py_DECREF(repr);
                }
                else {
                        strcpy(pbuf, "...");
-                       pbuf += 5;
+                       pbuf += 3;
+                       removelast = 0;
                        Py_DECREF(repr);
                        break;
                }
        }
        Py_DECREF(tup);
-
-       pbuf-=2;
+       if (removelast) {
+               /* overwrite last ", " */
+               pbuf-=2;
+       }
        *pbuf++ = ')';
        *pbuf = '\0';
 
-       repr = PyString_FromString(buf);
-       return repr;
+       return PyString_FromString(buf);
 }
 
 static PyObject *