commit fa25a7d51fdc4c21ac569d9f62825e337a7a6b4a
author Fredrik Lundh <fredrik@pythonware.com> Sun Jan 14 23:55:55 2001 +0000
committer Fredrik Lundh <fredrik@pythonware.com> Sun Jan 14 23:55:55 2001 +0000
tree f3a9df2c2b4578172e1e9b5116e3da5428870520
parent 07e99cb77406e1bc84606f49b743e41b0de8a6d5

-- don't use recursion for unbounded non-greedy repeat
(bugs #115903, #115696)

This is based on a patch by Darrel Gallion.  I'm not 100%
sure about this fix, but I haven't managed to come up with
any test case it cannot handle...

Modules/_sre.c

diff --git a/Modules/_sre.c b/Modules/_sre.c
index 28ec61c..b040d87 100644
--- a/Modules/_sre.c
+++ b/Modules/_sre.c
@@ -24,6 +24,7 @@
  * 2000-10-24 fl  really fixed assert_not; reset groups in findall
  * 2000-12-21 fl  fixed memory leak in groupdict
  * 2001-01-02 fl  properly reset pointer after failed assertion in MIN_UNTIL
+ * 2001-01-15 fl  don't use recursion for unbounded MIN_UTIL
  *
  * Copyright (c) 1997-2001 by Secret Labs AB.  All rights reserved.
  *
@@ -38,7 +39,7 @@
 
 #ifndef SRE_RECURSIVE
 
-char copyright[] = " SRE 0.9.9 Copyright (c) 1997-2000 by Secret Labs AB ";
+char copyright[] = " SRE 0.9.9 Copyright (c) 1997-2001 by Secret Labs AB ";
 
 #include "Python.h"
 
@@ -1012,11 +1013,21 @@
 
             /* see if the tail matches */
             state->repeat = rp->prev;
-            i = SRE_MATCH(state, pattern, level + 1);
+            if (rp->pattern[2] == 65535) {
+                /* unbounded repeat */
+                for (;;) {
+                    i = SRE_MATCH(state, pattern, level + 1);
+                    if (i || ptr >= end)
+                        break;
+                    state->ptr = ++ptr;
+                }
+            } else
+                i = SRE_MATCH(state, pattern, level + 1);
             if (i) {
                 /* free(rp); */
                 return i;
             }
+
             state->ptr = ptr;
             state->repeat = rp;