Restore min_size optimization

Author: vstinner

Objects/stringlib/codecs.h

@@ -350,6 +350,8 @@ STRINGLIB(utf8_encoder)(PyObject *unicode,
                 break;
 
             case _Py_ERROR_BACKSLASHREPLACE:
+                /* subtract preallocated bytes */
+                writer->size -= max_char_size * (endpos - startpos);
                 p = backslashreplace(writer, p,
                                      unicode, startpos, endpos);
                 if (p == NULL)
@@ -358,6 +360,8 @@ STRINGLIB(utf8_encoder)(PyObject *unicode,
                 break;
 
             case _Py_ERROR_XMLCHARREFREPLACE:
+                /* subtract preallocated bytes */
+                writer->size -= max_char_size * (endpos - startpos);
                 p = xmlcharrefreplace(writer, p,
                                       unicode, startpos, endpos);
                 if (p == NULL)
@@ -396,6 +400,8 @@ STRINGLIB(utf8_encoder)(PyObject *unicode,
                     }
                 }
                 else {
+                    /* subtract preallocated bytes */
+                    writer->size -= max_char_size * (newpos - startpos);
                     /* Only overallocate the buffer if it's not the last write */
                     writer->overallocate = (newpos < size);
                 }

Objects/unicodeobject.c

@@ -7414,6 +7414,8 @@ unicode_encode_ucs1(PyObject *unicode,
                 break;
 
             case _Py_ERROR_BACKSLASHREPLACE:
+                /* subtract preallocated bytes */
+                writer->size -= (collend - collstart);
                 str = backslashreplace(writer, str,
                                        unicode, collstart, collend);
                 if (str == NULL)
@@ -7422,6 +7424,8 @@ unicode_encode_ucs1(PyObject *unicode,
                 break;
 
             case _Py_ERROR_XMLCHARREFREPLACE:
+                /* subtract preallocated bytes */
+                writer->size -= (collend - collstart);
                 str = xmlcharrefreplace(writer, str,
                                         unicode, collstart, collend);
                 if (str == NULL)
@@ -7462,6 +7466,8 @@ unicode_encode_ucs1(PyObject *unicode,
                     }
                 }
                 else {
+                    /* subtract preallocated bytes */
+                    writer->size -= newpos - collstart;
                     /* Only overallocate the buffer if it's not the last write */
                     writer->overallocate = (newpos < size);
                 }