Issue 3116: fix quadratic behavior in marshal.dumps().
diff --git a/Misc/NEWS b/Misc/NEWS
index eeeaab0..cd44835 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -50,6 +50,8 @@
Extension Modules
-----------------
+- Issue #3116: marshal.dumps() had quadratic behavior for strings > 32Mb.
+
- Issue #2138: Add factorial() the math module.
- The heapq module does comparisons using LT instead of LE. This
diff --git a/Python/marshal.c b/Python/marshal.c
index 6db46e4..140192f 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -67,7 +67,7 @@
size = PyString_Size(p->str);
newsize = size + size + 1024;
if (newsize > 32*1024*1024) {
- newsize = size + 1024*1024;
+ newsize = size + (size >> 3); /* 12.5% overallocation */
}
if (_PyString_Resize(&p->str, newsize) != 0) {
p->ptr = p->end = NULL;