also test unicode and fix the JSONDecodeError issue

CHANGES.txt

 Version 2.1.7 released 2011-XX-XX
 
+* JSONDecodeError is now raised instead of ValueError when a document
+  ends with an opening quote and the C speedups are in use.
+  https://github.com/simplejson/simplejson/issues/15
 * Updated documentation with information about JSONDecodeError
 * Force unicode linebreak characters to be escaped (U+2028 and U+2029)
   http://timelessrepo.com/json-isnt-a-javascript-subset

simplejson/_speedups.c

@@ -483,7 +483,10 @@
     PyObject *chunks = NULL;
     PyObject *chunk = NULL;
 
-    if (end < 0 || len <= end) {
+    if (len == end) {
+        raise_errmsg("Unterminated string starting at", pystr, begin);
+    }
+    else if (end < 0 || len < end) {
         PyErr_SetString(PyExc_ValueError, "end is out of bounds");
         goto bail;
     }
@@ -689,7 +692,10 @@
     PyObject *chunks = NULL;
     PyObject *chunk = NULL;
 
-    if (end < 0 || len <= end) {
+    if (len == end) {
+        raise_errmsg("Unterminated string starting at", pystr, begin);
+    }
+    else if (end < 0 || len < end) {
         PyErr_SetString(PyExc_ValueError, "end is out of bounds");
         goto bail;
     }

simplejson/tests/test_errors.py

@@ -22,4 +22,5 @@
 
     def test_scan_error(self):
         err = None
+        for t in (str, unicode):
             try:
@@ -25,5 +26,5 @@
             try:
-            json.loads('{"asdf": "')
+                json.loads(t('{"asdf": "'))
             except json.JSONDecodeError, e:
                 err = e
             else: