Git issue 495: Running time for failing fullmatch increases rapidly w…

…ith input length

Re-enabled modified repeat guards due to regression in speed caused by excessive backtracking.

regex_3/_regex.c

@@ -23178,7 +23178,10 @@ Py_LOCAL_INLINE(RE_STATUS_T) add_repeat_guards(PatternObject* pattern, RE_Node*
                       RE_STATUS_REF);
 
                     repeat_info = &pattern->repeat_info[node->values[0]];
-                    repeat_info->status |= RE_STATUS_BODY;
+                    /* Removing guard here to fix issue 494 and prevent
+                     * regression of issue 495. 
+                     */
+                    /* repeat_info->status |= RE_STATUS_BODY; */
 
                     if (tail_result != RE_STATUS_REF)
                         repeat_info->status |= RE_STATUS_TAIL;
@@ -23639,7 +23642,7 @@ Py_LOCAL_INLINE(BOOL) optimise_pattern(PatternObject* pattern) {
     /* Add position guards for repeat bodies containing a reference to a group
      * or repeat tails followed at some point by a reference to a group.
      */
-    //add_repeat_guards(pattern, pattern->start_node);
+    add_repeat_guards(pattern, pattern->start_node);
 
     /* Record the index of repeats and fuzzy sections within the body of atomic
      * and lookaround nodes.

regex_3/regex.py

@@ -241,7 +241,7 @@
   "VERSION1", "X", "VERBOSE", "W", "WORD", "error", "Regex", "__version__",
   "__doc__", "RegexFlag"]
 
-__version__ = "2.5.124"
+__version__ = "2.5.125"
 
 # --------------------------------------------------------------------
 # Public interface.

setup.py

@@ -7,7 +7,7 @@
 
 setup(
     name='regex',
-    version='2023.3.22',
+    version='2023.3.23',
     description='Alternative regular expression module, to replace re.',
     long_description=long_description,
     long_description_content_type='text/x-rst',