Store the current regex syntax along with the regular expression

string as the key to the cache.  This means that changing the syntax
will return the correct compiled pattern.

clear_cache(): New function.

diff --git a/Lib/regsub.py b/Lib/regsub.py
index c87ac262aa2d1deffe289523b931eda8d1eed2eb..8fb33065ed2269148227483fc0dadfd30b43b02b 100644 (file)
--- a/Lib/regsub.py
+++ b/Lib/regsub.py
@@ -109,27 +109,32 @@ def capwords(str, pat='[^a-zA-Z0-9_]+'):
 
 
 # Manage a cache of compiled regular expressions.
-# If the pattern is a string a compiled version of it is returned.
-# If the pattern has been used before we return an already compiled
+#
+# If the pattern is a string a compiled version of it is returned.  If
+# the pattern has been used before we return an already compiled
 # version from the cache; otherwise we compile it now and save the
-# compiled version in the cache.
-# Instead of a string, a compiled regular expression can also be
-# passed.
-# WARNING: if the pattern syntax is changed, the cache should be
-# flushed!
+# compiled version in the cache, along with the syntax it was compiled
+# with.  Instead of a string, a compiled regular expression can also
+# be passed.
 
 cache = {}
 
 def compile(pat):
        if type(pat) <> type(''):
                return pat              # Assume it is a compiled regex
-       if cache.has_key(pat):
-               prog = cache[pat]       # Get it from the cache
+       key = (pat, regex.get_syntax())
+       if cache.has_key(key):
+               prog = cache[key]       # Get it from the cache
        else:
-               prog = cache[pat] = regex.compile(pat)
+               prog = cache[key] = regex.compile(pat)
        return prog
 
 
+def clear_cache():
+       global cache
+       cache = {}
+
+
 # Expand \digit in the replacement.
 # Each occurrence of \digit is replaced by the substring of str
 # indicated by regs[digit].  To include a literal \ in the