-- added recursion limit (currently ~10,000 levels)

-- improved error messages
-- factored out SRE_COUNT; the same code is used by
   SRE_OP_REPEAT_ONE_TEMPLATE
-- minor cleanups

Lib/test/output/test_sre

 test_sre
+maximum recursion limit exceeded

Lib/test/test_sre.py

@@ -264,6 +264,16 @@ for flags in [sre.I, sre.M, sre.X, sre.S, sre.L, sre.T, sre.U]:
     except:
         print 'Exception raised on flag', flags
 
+if verbose:
+    print 'Test engine limitations'
+
+# Try nasty case that overflows the straightforward recursive
+# implementation of repeated groups.
+try:
+    assert sre.match('(x)*', 50000*'x').span() == (0, 50000)
+except RuntimeError, v:
+    print v
+
 from re_tests import *
 
 if verbose:

Modules/sre.h

@@ -74,8 +74,6 @@ typedef struct {
     SRE_REPEAT *repeat; /* current repeat context */
     /* hooks */
     SRE_TOLOWER_HOOK lower;
-    /* debugging */
-    int maxlevel;
 } SRE_STATE;
 
 typedef struct {