commit c9d369f1bf78c48083679b2afa5f31d8378ea94d
author Victor Stinner <victor.stinner@gmail.com> Sat Jun 16 02:22:37 2012 +0200
committer Victor Stinner <victor.stinner@gmail.com> Sat Jun 16 02:22:37 2012 +0200
tree 610388d08918fbb6fdafa6e5f7fa7123d0ec8a19
parent f05e17ece9ee4cf4d04e0657e6c7c9283a233968

Optimize _PyUnicode_FastCopyCharacters() when maxchar(from) > maxchar(to)

Python/formatter_unicode.c

diff --git a/Python/formatter_unicode.c b/Python/formatter_unicode.c
index fdb587d..cd66670 100644
--- a/Python/formatter_unicode.c
+++ b/Python/formatter_unicode.c
@@ -786,8 +786,10 @@
         goto done;
 
     /* Then the source string. */
-    _PyUnicode_FastCopyCharacters(writer->buffer, writer->pos,
-                                  value, 0, len);
+    if (len) {
+        _PyUnicode_FastCopyCharacters(writer->buffer, writer->pos,
+                                      value, 0, len);
+    }
     writer->pos += (len + rpad);
     result = 0;